Antiproteinuric Effect of Sulodexide versus Losartan in Primary Glomerulonephritis

Abdul Halim Abdul Gafor, Wan Hazlina Wan Mohamad, Rozita Mohd, Rizna Abdul Cader, Kong Wei Yen, Shamsul Azhar Shah, Norella C. T. Kong

Department of Epidemiology and Biostatistics, University Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latif, Bandar Tun Razak, Cheras, Kuala Lumpur, Malaysia.
Nephrology Unit, Department of Medicine, University Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latif, Bandar Tun Razak, Cheras, Kuala Lumpur, Malaysia.

DOI: 10.4236/ojneph.2014.42010                

Abstract

Introduction: Limited data are available for the use of sulodexide in primary glomerulonephritis (GN). Objective: We studied the efficacy of sulodexide compared to losartan in patients with primary GN. Design and Method: This was a prospective, open labelled, randomized control trial in patients with stable primary GN. Patients were randomized to receive either sulodexide or losartan to maximum tolerated doses for 12 weeks. Blood and urine investigations were measured at baseline and at 4-weekly intervals. Adverse effects were recorded. Results: 18 patients were recruited (10-sulodexide and 8-losartan). Their baseline characteristics were comparable. At end study, patients in both groups showed no significant reduction in proteinuria and there were no differences between groups at each visit. Nonetheless, there was a trend towards lower protein uria in the losartan but not in sulodexide group. There were no changes in the other parameters of renal function or of coagulation over time. No adverse events in particular clinical bleeding occurred. Conclusion: Sulodexide and losartan did not demonstrate any significant anti-proteinuric effect in primary GN. Nevertheless, there was a trend of better proteinuria reduction in losartan group. Furthermore, other renal parameters were not significantly affected by both drugs.

Keywords

Antiproteinuria, Losartan, Primary Glomerulonephritis, Sulodexide

1. Introduction

Glomerulonephritis (GN) is a renal disease characterized by inflammation of the glomeruli, or small blood vessels in the kidneys. GN is broadly categorized into primary GN and secondary GN. Primary GN is due to intrinsic causes to the kidney while secondary GN is due to infection, drugs, diabetes mellitus or systemic disorders. Primary GN includes minimal change disease (MCN), focal segmental glomerulosclerosis (FSGS), primary membranous GN, immunoglobulin A nephropathy (IgAN) and various proliferative GN.

Little is known about the worldwide variation in incidence of primary GN. A systemic review had shown the incidence of primary GN to vary between 0.2/100,000/year and 2.5/100,000/year worldwide [1] . The commonest primary GN reported by the 3^rd report of the Malaysian Registry of Renal Biopsy 2009 was MCN (33.4%), FSGS (29.3%) followed by IgAN (19.6%) and idiopathic membranous nephropathy (9.8%) [2] . GN is the third leading cause of end stage renal disease (ESRD) in United States [3] and fourth in the Malaysian population [4] .

Proteinuria is the clinical hallmark of GN and is the most important predictor of outcome. It is also an independent determinant of the progression of chronic kidney disease (CKD)―the greater the proteinuria the more rapid decline of renal function [5] -[7] . These patients also have increased cardiovascular risk which is further aggravated by reduction of the glomerulofiltration rate (GFR) [8] . Hence, therapeutic intervention that reduces the level of proteinuria should impact the progression of proteinuric nephropathies.

As most primary GN is immune mediated, immunosuppressive therapy is an important first line treatment. The next therapeutic approach is the inhibition of the renin-angiotensin-aldosterone system (RAAS) by using angiotensin-converting enzymes inhibitors (ACE-I) and/or angiotensin II receptor blockers (ARBs) and/or aldosterone receptor blockers. These have both antihypertensive and antiproteinuric properties and have been shown to significantly reduce the rate of progression of both diabetic and non diabetic nephropathies [9] -[12] .

One of the pathogenic mechanisms leading to proteinuria in GN, involves an alteration in heparin sulfate (HS) expression in glomerular basement membrane (GBM). HS is a member of the family of glycosaminoglycans (GAGs) that is generally bound to a core protein to form a proteoglycan (PG). Alterations in HS expression in the GBM had been reported in many proteinuric renal diseases which include diabetic nephropathy, minimal change nephropathy and membranous GN [13] . The decrease of HS content causes a reduction on the permselectivity to negatively charged macromolecules such as albumin thus allowing protein leak into the urinary space.

Sulodexide is a highly purified mixture of GAGs composed of a fast-moving heparin like substance (80%) and dermatan sulphate (20%), with a low molecular weight, a high oral bioavailability and possesses antithrombotic and profibrinolytic activities [14] . This mixture of GAGs is highly purified from porcine intestinal mucosa by a patented process. It is concentrates in the renal parenchyma for a long time after administration [15] . It was shown to reduce proteinuria in patients with diabetes kidney disease (DKD) and non DKD [16] -[23] .

In addition to increasing the permselectivity of the GBM, sulodexide also inhibits mesangial cell proliferation [24] and exerts an antimitogenic effect on glomerular epithelial cells [25] . It reduces transforming growth factor- β expression and has an anti-thrombotic effect which helps to further reduce proteinuria [24] [26] [27] .

The fast moving heparin (FMH) and dermatan sulphate (DS) accelerate the inhibition of thrombin by their interaction with ATIII and heparin cofactor II (HCII) and directly inhibit thrombin and thrombin generation by inhibiting the feedback activation of prothrombin. Sulodexide also prolongs the thrombin clotting time and the activated partial thromboplastin time (aPTT) [28] [29] . Several clinical trials have demonstrated the beneficial effect of sulodexide in the treatment of deep vein thrombosis [30] [31] , venous leg ulcers [32] and intermittent claudication [33] .

Most studies of the antiprotenuric effect of sulodexide have been carried out in patients with type 1 and/or type 2 diabetes mellitus. The antiproteinuric effect of sulodexide in proteinuric chronic primary GN is less well studied [34] .

Most studies investigating the use of sulodexide as a novel antiproteinuric agent that works on perm selectivity of the GBM have been performed in patients with DKD and non DKD and many have reported that sulodexide had a significant antiproteinuric effect with or without added RAAS blockade [17] [18] [20] -[22] . However, there are no studies that have directly compared sulodexide and a RAAS blocker (e.g. losartan) as antiproteinuric agents. Hence we would like to perform a head-to-head comparison of this novel GAG with the ARB, losartan to evaluate the efficacy of sulodexide as an alternative antiproteinuric agent in primary GN.

Our primary objective was to evaluate the antiproteinuric effect of sulodexide compared to losartan, an ARB in primary GN. Our secondary objectives were to evaluate the effect of sulodexide compared to losartan on other parameters of renal function and determine the safety of sulodexide on parameters of coagulation.

2. Methodology

2.1. Patients and Method

This was a prospective open labelled randomized control trial involving patients with primary GN on follow up at the Nephrology Unit, Universiti Kebangsaan Malaysia Medical Centre (UKMMC). The study approved by the local Ethics & Research Committee (FF-454-2011).

Only patients with proteinuria of 0.3 g - 3.5 g/day and CKD stages 1 - 3 (eGFR > 30 ml/min/1.73m²) with the diagnosis of primary GN included in this study. Patients on stable maintenance immunosuppressive therapy were included without altering the immunosuppressive drug. All patients had blood pressure of ≤ 150/90 mmHg and serum potassium of < 5.5 mmol/L at recruitment. Patients with known renal artery stenosis or allergy to study drugs were excluded from this study. Pregnant or lactating patients and patients with childbearing potential without effective method of birth control were also excluded from this study.

2.2. Randomization

Patients who met the eligibility criteria were recruited. Prior to randomization patients who were on RAAS blockers underwent a 4-week washout period. Other antihypertensive medications were continued. The patients were reviewed 2-weekly during the washout period and target systolic BP ≤ 150 mmHg and diastolic BP ≤ 90 mmHg were maintained. Other antihypertensive medications were added and/or dose adjusted until target blood pressure was achieved. Patients naïve to losartan and those who had undergone the RAAS blocker washout period were randomized into the sulodexide or losartan arms. Randomization was done in blocks of four. A short sequence of four probable alphabetical orders of AB combination were put in an envelope and pulled out as patients were recruited.

2.3. Study Protocol

At study entry, full blood count, coagulation profiles and blood samples for renal, liver and lipid profiles were taken. Spot urine sample urine Protein Creatinine Index (uPCI) was also taken. The treatment was for 12 weeks. Patients were reviewed at Weeks 0 (baseline), 2, 4 (V1), 8 (V2) and 12 (V3). At Weeks 4 (V1), 8 (V2) and 12 (V3)-blood pressure, uPCI and blood investigations listed above were taken each visit except for the estimated GFR (eGFR), coagulation and lipid parameters which were evaluated at the beginning (V0) and end of the study-Week 12 (V3). The eGFR was calculated by the Modification of Diet in Renal disease (MDRD) formula.

Losartan and sulodexide doses were titrated up to the maximum tolerated dose as judged by blood pressure. Losartan dosages ranged from 50 - 100 mg daily and those for sulodexide from 100 - 200 mg daily. Patients were strongly advised to adhere to the study drugs given and to report any adverse reactions either by phone or during clinic visits. Patient compliance to study treatment was assessed by pill counts. Compliance was taken as adherence with medications ≥80% of the time.

2.4. Statistical Analysis

All data were recorded and analyzed using the statistical package Statistical Package for the Social Sciences version 20 (IBM SPSS, Armonk, NY: IBM Corp). Our sample size was small and was not normally distributed; hence non-parametric tests were used. Results were expressed as median with interquartile range (IQR). The differences between two groups were analyzed using the Mann-Whitney-U test. Related data across time were analyzed using both the Wilcoxon Rank test and the Friedman’s analysis. Nominal and ordinal data were analyzed using Fisher’s exact test. A p value of < 0.05 was considered significant.

3. Results

Eighty seven patients were screened and 34 patients were noted to be in complete remission with proteinuria < 0.3 g/day. Ten patients were excluded as they were not on stable immunosuppressive therapies. Eight patients had CKD above stage 3, 7 patients declined, 4 patients were non compliant to medications, 4 females had breast cancer and 2 females were pregnant. Hence only 18 patients were recruited with 10 patients randomized to receive sulodexide and eight patients to losartan.

Baseline demographics and clinical characteristics were tabulated in Table 1. Baseline laboratory investigations were tabulated in Table 2.

Median dose for sulodexide was 150 (100 - 200) mg daily and losartan was 75 (50 - 100) mg daily. The use of other concurrent medications including antihypertensive, statin, aspirin and immunosuppressive medication were the same between both groups. There was no significant difference of blood pressure across the study duration in both study groups.

Both groups did not show any significant reduction in proteinuria whether intragroup or intergroup and across all visits. Nonetheless, the losartan arm had a trend towards lower proteinuria at end study whilst in the sulodexide group, proteinuria levels remained static (Figure 1).

Other renal parameters results were tabulated in Table 3. There were no significant differences in all the parameters in between and within both groups.

Over the 12 weeks of treatment, there were no significant changes in the full blood count parameters nor prothrombin time (PT), international normalized ratio (INR) and activated partial thromboplastin time (APTT) in patients in the sulodexide arm. There were also no clinical episodes of bleeding and no other adverse effects occurred.

4. Discussion

Primary GN is one of the common renal diseases that progress to ESRD. Besides immunosuppressive medications, RAAS blockade play an important role in the treatment of primary GN and reduction of proteinuria by reducing the intraglomerular pressure. A few randomized trials have shown that losartan has significant antiproteinuric effect in primary GN [35] -[39] .

Table 1. Baseline demographics and clinical characteristics of the study groups.

Results in median (IQR), IQR: interquartile range; IgAN: IgA nephropathy; FSGS: Focal segmental glomerulosclerosis; p value < 0.05 is significant.

Table 2. Baseline laboratory parameters of the two study groups.

Results in median (IQR), IQR: interquartile range; uPCI: urine protein index; CKD: Chronic Kidney Disease; eGFR: estimated glomerular filtration rate; HDL: high-density lipoprotein; LDL: low-density lipoprotein; p value < 0.05 is significant.

Figure 1. uPCI across the study period in both groups.

 

Table 3. Other renal parameters across the study period and in between the two groups.

Results in median (IQR), IQR: interquartile range; eGFR: estimated glomerular filtration rate; p value^*: Intra-group analysis using Friedman’s analysis; p value: intergroup using Mann-Whitney-U test; p value < 0.05 is significant.

In our study, there was no significant antiproteinuric property in both losartan and sulodexide groups. Nevertheless there was a trend towards significance of proteinuria reduction in the losartan group.

These rather disappointing results in losartan group can be explained by a short study duration of 12 weeks and a the lower median dose of 75 mg daily used due to patient intolerance as manifested by a lowish blood pressure. In DKD, it is a fact that RAAS blockers exert maximal antiproteinuric effects after 6 months of treatment [9] [12] [40] [41] . In several studies using losartan as antiproteinuric agent in non-DKD, losartan even at low doses of 25 - 50 mg were sufficient to significantly reduce proteinuria in primary GN as hypertension is not universal in early non-DKD [38] . Large multicenter trials have also demonstrated the optimum antiproteinuric dose of losartan to be 100 mg daily and that no beneficial effects were seen beyond this dose [42] -[44] . Furthermore, from the extensive experience with the use of RAAS blockers in DKD and more recently in non-DKD, the higher the baseline proteinuria, the greater the proteinuria reduction [5] [9] [11] [12] . Thus, the low baseline proteinuria, low median dose of losartan and short duration of our study may account for the lowered antiproteinuric performance of losartan in our study.

To date, large trials of sulodexide have been conducted only in hypertensive patients with type 2 diabetes mellitus (DM) [20] -[22] . Its use in proteinuric chronic GN is very recent and followed the failure of the SUNMicro-trial in which sulodexide at the optimal dose of 200 mg daily did not further reduce microalbuminuria [21] . The SUN-Macro-trial which was terminated prematurely by the sponsor had already recruited more than 2000 hypertensive type 2 DM patients with a mean follow-up of 11 months [22] .

Several published studies, which included only a small number of patients, had previously investigated the effect of sulodexide on proteinuria in chronic non-DKD [17] -[19] [45] . Almost all these studies on non-DKD involved the use of sulodexide with an ACE-I or ARB. To our knowledge, there has been no head-to-head comparison between sulodexide versus a RAAS blocker in proteinuric renal disease, diabetic or non-diabetic. We believed this was the first study to investigate the antiproteinuric property of sulodexide as a sole antiproteinuric agent in primary GN.

A recent multicenter study by Kitae Bang et al. of sulodexide involved 77 patients with IgA nephropathy who despite RAAS blockade remained proteinuric. They were randomized to receive placebo, sulodexide 75 mg daily or sulodexide 150 mg daily. At the end of 16 weeks only those on sulodexide 150 mg daily had a significant reduction in proteinuria [17] .

In a retrospective review, BY Yang et al. reported their experience with 20 patients with IgA nephropathy treated with sulodexide 50 mg daily as add-on therapy to optimized RAAS blockade. The investigators found a significant reduction of proteinuria and also noted the higher the baseline levels of proteinuria the greater the reduction [18] .

As our study was a head-to-head comparison of sulodexide to losartan, it was not appropriate to compare our results with those of the above studies, which evaluated sulodexide as add-on therapy to RAAS blockade in proteinuric non DKD.

The median dose of sulodexide used was 150 mg daily (100 - 200 mg). In the literature, no previous study had specifically addressed the optimal dose of SDX in primary GN. In earlier study, Gambaro G et al. demonstrated a significant reduction of proteinuria with increasing oral doses of sulodexide from 50 mg to 100 mg to 200 mg daily [20] . In a recent study of patients with IgA nephropathy, sulodexide at 150 mg daily had significant antiproteinuric effects up to 4 months of treatment and maximized at 6 months [17] . Another study by Byeong Yun Yang et al. reported that even lower sulodexide doses of 50 mg daily as add-on to ACE-I/ARB resulted in ≥ 50% reduction in IgA nephropthy [18] . The shorter study duration of 12-week could explain the lack of antiproteinuric efficacy of sulodexide in our study.

Serum creatinine and eGFR were stable throughout the study period of 12 weeks and there were no differences seen within or between the two treatment groups. There was even a slight improvement in the serum creatinine and eGFR in both groups. These findings are consistent with other reports of the use of sulodexide in IgA nephropathy [17] [18] as well as in diabetic nephropathy [20] . Studies of losartan in primary GN also reported similar findings to ours [13] [37] .

Serum uric acid has emerged as a risk marker for progression of CKD [46] . Hyperuricaemia increases blood pressure, proteinuria, renal dysfunction and renal scarring [46] . The changes of serum uric acid levels in our study patients were not significant in both groups. So far, there have been no reports on changes of serum uric acid in the earlier sulodexide studies [17] -[20] . In contrast, losartan has been proven to reduce serum uric acid and delay renal progression in patients with DKD [47] . There were no changes seen in the serum haemoglobin, platelet count, protrombin time, INR and aPTT after 12 weeks of treatment in our study. This is consistent with findings from numerous trials with sulodexide for renal disease including D.I.N.A.S [20] . No adverse events such as rash, diarrhea, musculoskeletal symptoms, epigastric pain and vomiting were observed in our study.

5. Conclusion

Sulodexide and losartan did not demonstrate any significant anti-proteinuric effect in primary GN. Nevertheless, there was a trend of better proteinuria reduction in losartan group. Furthermore, other renal parameters were not significantly affected by both drugs. These findings may be due to lower dose of study drugs, shorter study duration and low baseline proteinuria in both groups. We found both drugs were safe and well tolerated by patients. A larger and longer study is indicated to confirm our findings.

Acknowledgements

We would like to thank the Dean of the Faculty of Medicine, Universiti Kebangsaan Malaysia, for allowing us to publish these data.

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Mc Grogan, A.F.C. and de Vries, C.S. (2011) The Incidence of Primary Glomerulonephritis Worldwide: A Systematic Review of the Literature. Nephrol Dial Transplant, 26, 414-430. http://dx.doi.org/10.1093/ndt/gfq665
[2]	Sunita, B. and Lim, S.K. (2009) 3rd Report of the Malaysian Registry of Renal Biopsy 2009. Primary Glomerulonephritis, 2, 24.
[3]	US Renal Data System, USRDS 2012 Annual Data Report (2012) Atlas of Chronic Kidney Disease and End-Stage Renal Disease in the United States. National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, 226.
[4]	Lim, Y.N., Ong, L.M., Ghazali, A. and Lee, D.G. (2012) Nineteen Report of Malaysian Dialysis and Transplantation Registry 2012: Dialysis in Malaysia. The National Renal Registry, Kuala Lumpur.
[5]	Ruggenenti, P., Perna, A., Mosconi, L., Pisoni, R. and Remuzzi, G. (1998) Urinary Protein Excretion Rate Is the Best Independent Predictor of ESRF in Non-Diabetic Proteinuric Chronic Nephropathies. “Gruppo Italiano di Studi Epidemiologici in Nefrologia” (GISEN). Kidney International, 53, 1209-1216. http://dx.doi.org/10.1046/j.1523-1755.1998.00874.x
[6]	Peterson, J.C., Adler, S., Burkart, J.M., Greene, T., Hebert, L.A., Hunsicker, L.G., et al. (1995) Blood Pressure Control, Proteinuria, and the Progression of Renal Disease. The Modification of Diet in Renal Disease Study. Annals of Internal Medicine, 123, 754-762. http://dx.doi.org/10.7326/0003-4819-123-10-199511150-00003
[7]	Lea, J., Greene, T., Hebert, et al. (2005) The Relationship between Magnitude of Proteinuria Reduction and Risk of End Stage Renal Disease: Results of the African American Study of Kidney Disease and Hypertension. Achives of Internal Medicine, 165, 2254-2261.
[8]	So, W.Y.K.K., Iseki, C., et al. (2006) Glomerular Filtration Rate, Cardiorenal End Points, and All Cause Mortality in Type 2 Diabetic Patients. Diabetes Care, 29, 2046-2052.
[9]	Lewis, E.J.H.L., Clarke, W.R., Berl, T., Pohl, M.A., Lewis, J.B., et al. (2001) Renoprotective Effect of the Angiotensin-Receptor Antagonist Irbesartan in Patients with Nephropathy Due to Type 2 Diabetes. New England Journal of Medicine, 345, 851-860. http://dx.doi.org/10.1056/NEJMoa011303
[10]	Maschio, G.A.D., Janin, G., Locatelli, F., Mann, J.F., Motolese, M., et al. (1996) Effect of the Angiotensin-Converting-Enzyme Inhibitor Benazepril on the Progression of Chronic Renal Insufficiency. The Angiotensin-Converting-Enzyme Inhibition in Progressive Renal Insufficiency Study Group. New England Journal of Medicine, 334, 939-945. http://dx.doi.org/10.1056/NEJM199604113341502
[11]	Group, T.G. (1997) Randomised Placebo Control Trial of Effect of Ramipril on Decline in Glomerular Filtration Rate and Risk of Terminal Renal Failure in Proteinuric, Non Diabetic Nephropathy. Lancet, 349, 1857-1863. http://dx.doi.org/10.1016/S0140-6736(96)11445-8
[12]	Brenner, B.M.C.M., de Zeeuw, D., Keane, W.F., Mitch, W.E., Parving, H.H., et al. (2001) Effects of Losartan on Renal and Cardiovascular Outcomes in Patients with Type 2 Diabetes and Nephropathy. New England Journal of Medicine, 345, 861-869. http://dx.doi.org/10.1056/NEJMoa011161
[13]	Jacob Van Den Born, L.W.J.V., Marinka, H.B., Jacquesh, V., Karel, J.M.A., Jan, J.W. and Jo, H.M.B. (1993) Distribution of GBM Heparan Sulfate Proteoglycan Core Protein and Side Chains in Human Glomerular Diseases. Kidney Intenational, 43, 454-463. http://dx.doi.org/10.1038/ki.1993.67
[14]	Harenberg, J. (1998) Review of Pharmacodynamics, Pharmacokinetics, and Therapeutic Properties of Sulodexide. Medicinal Research Reviews, 18, 1-20. http://dx.doi.org/10.1002/(SICI)1098-1128(199801)18:1<1::AID-MED1>3.0.CO;2-4
[15]	Ruggeri, A., Guizzardi, S., Franchi, M., Morocutti, M. and Mastacchi, R. (1985) Pharmacokinetics and Distribution of a Fluoresceinated Glycosaminoglycan, Sulodexide, in Rats. Part II: Organ Distribution in Rats. Arzneimittelforschung, 35, 1517-1519.
[16]	Dedov, I., Shestakova, M., Vorontzov, A. and Palazzini, E. (1997) A Randomized, Controlled Study of Sulodexide Therapy for the Treatment of Diabetic Nephropathy. Nephrology Dialysis Transplantation, 12, 2295-2300. http://dx.doi.org/10.1093/ndt/12.11.2295
[17]	Bang, K., Chin, H.J., Chae, D.W., Joo, K.W., Kim, Y.S., Kim, S., et al. (2011) Anti-Proteinuric Effect of Sulodexide in Immunoglobulin A Nephropathy. Yonsei Medical Journal, 52, 588-594. http://dx.doi.org/10.3349/ymj.2011.52.4.588
[18]	Yang, B.Y., Lee, H.S., Song, S.H., Kwak, I.S., Lee, S.B., Lee, D.W., et al. (2012) Use of Low-Dose Sulodexide in IgA Nephropathy Patients on Renin-Angiotensin System Blockades. Kidney Research and Clinical Practice, 31, 163-169. http://dx.doi.org/10.1016/j.krcp.2012.06.006
[19]	Rozita, M., Loo, C.Y., et al. (2008) Glycosaminoglycans (Sulodexide) for Resistant Heavy Proteinuria of Chronic Glomerulonephritides (Abstract). 11th Asian Pacific Congress of Nephrology, Kuala Lumpur, 5-8 May 2008.
[20]	Gambaro, G., Kinalska, I., Oksa, A., Pont’uch, P., Hertlová, M., Olsovsky, J., et al. (2002) Oral Sulodexide Reduces Albuminuria in Microalbuminuric and Macroalbuminuric Type 1 and Type 2 Diabetic Patients: The Di.N.A.S. Randomized Trial. Journal of the American Society of Nephrology, 13, 1615-1625. http://dx.doi.org/10.1097/01.ASN.0000014254.87188.E5
[21]	Lewis, E.J., Lewis, J.B., Greene, T., Hunsicker, L.G., Berl, T., Pohl, M.A., et al. (2011) Sulodexide for Kidney Protection in Type 2 Diabetes Patients with Microalbuminuria: A Randomized Controlled Trial. American Journal of Kidney Diseases, 58, 729-736. http://dx.doi.org/10.1053/j.ajkd.2011.06.020
[22]	Packham, D.K., Wolfe, R., Reutens, A.T., Berl, T., Heerspink, H.L., Rohde, R., et al. (2012) Sulodexide Fails to Demonstrate Renoprotection in Overt Type 2 Diabetic Nephropathy. Journal of the American Society of Nephrology, 23, 123-130.
[23]	Gambaro, G., Venturini, A.P., Noonan, D.M., Fries, W., Re, G., Garbisa, S., et al. (1994) Treatment with a Glycosaminoglycan Formulation Ameliorates Experimental Diabetic Nephropathy. Kidney International, 46, 797-806. http://dx.doi.org/10.1038/ki.1994.335
[24]	Caenazzo, C., Garbisa, S., Ceol, M., Baggio, B., Borsatti, A., Marchi, E., et al. (1995) Heparin Modulates Proliferation and Proteoglycan Biosynthesis in Murine Mesangial Cells: Molecular Clues for Its Activity in Nephropathy. Nephrology Dialysis Transplantation, 10, 175-184.
[25]	Ceol, M., Gambaro, G., Sauer, U., Baggio, B., Anglani, F., Forino, M., et al. (2000) Glycosaminoglycan Therapy Prevents TGF-Beta1 Overexpression and Pathologic Changes in Renal Tissue of Long-Term Diabetic Rats. Journal of the American Society of Nephrology, 11, 2324-2336.
[26]	Lewis, E.J. and Xu, X. (2008) Abnormal Glomerular Permeability Characteristics in Diabetic Nephropathy: Implications for the Therapeutic Use of Low-Molecular Weight Heparin. Diabetes Care, 31, S202-S207. http://dx.doi.org/10.2337/dc08-s251
[27]	Gambaro, G. and Kong, N.C. (2010) Glycosaminoglycan Treatment in Glomerulonephritis? An Interesting Option to Investigate. Journal of Nephrology, 23, 244-252.
[28]	Linhardt, R.J., Al-Hakim, A., Liu, J.A., Hoppensteadt, D., Mascellani, G., Bianchini, P., et al. (1991) Structural Features of Dermatan Sulfates and Their Relationship to Anticoagulant and Antithrombotic Activities. Biochemical Pharmacology, 42, 1609-1619. http://dx.doi.org/10.1016/0006-2952(91)90431-4
[29]	Furie, B. and Furie, B.C. (1992) Molecular and Cellular Biology of Blood Coagulation. The New England Journal of Medicine, 326, 800-806. http://dx.doi.org/10.1056/NEJM199203193261205
[30]	Cirujeda, J.L. and Granado, P.C. (2006) A Study on the Safety, Efficacy, and Efficiency of Sulodexide Compared with Acenocoumarol in Secondary Prophylaxis in Patients with Deep Venous Thrombosis. Angiology, 57, 53-64. http://dx.doi.org/10.1177/000331970605700108
[31]	Errichi, B.M., Cesarone, M.R., Belcaro, G., Marinucci, R., Ricci, A., Ippolito, A., et al. (2004) Prevention of Recurrent Deep Venous Thrombosis with Sulodexide: The SanVal Registry. Angiology, 55, 243-249. http://dx.doi.org/10.1177/000331970405500302
[32]	Coccheri, S., Scondotto, G., Agnelli, G., Aloisi, D., Palazzini, E., Zamboni, V., et al. (2002) Randomised, Double Blind, Multicentre, Placebo Controlled Study of Sulodexide in the Treatment of Venous Leg Ulcers. Thrombosis and Haemostasis, 87, 947-952.
[33]	Coccheri, S., Scondotto, G., Agnelli, G., Palazzini, E. and Zamboni, V. (2002) Sulodexide in the Treatment of Intermittent Claudication. Results of a Randomized, Double-Blind, Multicentre, Placebo-Controlled Study. European Heart Journal, 23, 1057-1065. http://dx.doi.org/10.1053/euhj.2001.3033
[34]	Gluhovschi, G.B.G., Petrica, L., et al. (2006) Nephroprotection, Part of Multi-Organprotection. Temporomandibular Joint Disorders, 56, 2-3.
[35]	Rutkowski, P., Tylicki, L., Renke, M., Korejwo, G., Zdrojewski, Z. and Rutkowski, B. (2004) Low-Dose Dual Blockade of the Renin-Angiotensin System in Patients with Primary Glomerulonephritis. American Journal of Kidney Diseases, 43, 260-268. http://dx.doi.org/10.1053/j.ajkd.2003.10.032
[36]	Renke, M., Tylicki, L., Rutkowski, P. and Rutkowski, B. (2004) Low-Dose Angiotensin II Receptor Antagonists and Angiotensin II-Converting Enzyme Inhibitors Alone or in Combination for Treatment of Primary Glomerulonephritis. Scandinavian Journal of Urology and Nephrology, 38, 427-433. http://dx.doi.org/10.1080/00365590410015687
[37]	Praga, M., Andrade, C.F., Luño, J., Arias, M., Poveda, R., Mora, J., et al. (2003) Antiproteinuric Efficacy of Losartan in Comparison with Amlodipine in Non-Diabetic Proteinuric Renal Diseases: A Double-Blind, Randomized Clinical Trial. Nephrology Dialysis Transplantation, 18, 1806-1813. http://dx.doi.org/10.1093/ndt/gfg284
[38]	Tylicki, L., Rutkowski, P., Renke, M. and Rutkowski, B. (2002) Renoprotective Effect of Small Doses of Losartan and Enalapril in Patients with Primary Glomerulonephritis. Short-Term Observation. American Journal of Nephrology, 22, 356-362. http://dx.doi.org/10.1159/000065227
[39]	Tylicki, L., Renke, M., Rutkowski, P., Rutkowski, B. and Lysiak-Szydlowska, W. (2005) Randomized, Controlled Study of the Effects of Losartan versus Enalapril in Small Doses on Proteinuria and Tubular Injury in Primary Glomerulonephritis. Medical Science Monitor, 11, 131-137.
[40]	Hou, F.F., Xie, D., Zhang, X., Chen, P.Y., Zhang, W.R., Liang, M., Guo, Z.J. and Jiang, J.P. (2007) Renoprotective of Optimal Antiproteinuric Doses (ROAD) Study: A Randomized Controlled Study of Benazepril and Losartan in Chronic Renal Insufficiency. Journal of the American Society of Nephrology, 18, 1889-1898. http://dx.doi.org/10.1681/ASN.2006121372
[41]	Mogensen, C.E., Neldam, S., Tikkanen, I., Oren, S., Viskoper, R., et al. (2000) Randomised Controlled Trial of Dual Blockade of Renin-Angiotensin System in Patients with Hypertension, Microalbuminuria, and Non-Insulin Dependent Diabetes: The Candesartan and Lisinopril Microalbuminuria (CALM) Study. BMJ, 321, 1440-1444.
[42]	Wright Jr., J.T., Bakris, G., Greene, T., Agodoa, L.Y., Appel, L.J., Charleston, J., et al. (2002) Effect of Blood Pressure Lowering and Antihypertensive Drug Class on Progression of Hypertensive Kidney Disease: Results from the AASK Trial. JAMA, 288, 2421-2431.
[43]	Arguedas, J.A., Perez, M.I. and Wright, J.M. (2009) Treatment Blood Pressure Targets for Hypertension. Cochrane Database of Systematic Reviews, Article ID: CD004349.
[44]	Andersen, S., Rossing, P., Juhl, T.R., Deinum, J. and Parving, H.H. (2002) Optimal Dose of Losartan for Renoprotection in Diabetic Nephropathy. Nephrology Dialysis Transplantation, 17, 1413-1418. http://dx.doi.org/10.1093/ndt/17.8.1413
[45]	Gluhovschi, A.S.G., Raica, M., Petrica, L., Trandafirescu, V., Velciov, S., Bozdog, G., Patrascu, C. and Gluhovschi, C. (2001) The Effects of the Therapy with Natural Glycosaminoglycans (Sulodexide) on Proteinuria in Different Types of Glomerulonephritis. Medicine and Biology, 8, 26-30.
[46]	Kang, D.H., Nakagawa, T., Feng, L., Watanabe, S., Han, L., Mazzali, M., et al. (2002) A Role for Uric Acid in the Progression of Renal Disease. Journal of the American Society of Nephrology, 13, 2888-2897. http://dx.doi.org/10.1097/01.ASN.0000034910.58454.FD
[47]	Miao, Y., Ottenbros, S.A., Laverman, G.D., Brenner, B.M., Cooper, M.E., Parving, H.H., et al. (2011) Effect of a Reduction in Uric Acid on Renal Outcomes during Losartan Treatment: A Post Hoc Analysis of the Reduction of Endpoints in Non-Insulin-Dependent Diabetes Mellitus with the Angiotensin II Antagonist Losartan Trial. Hypertension, 58, 2-7. http://dx.doi.org/10.1161/HYPERTENSIONAHA.111.171488