Relationship between the Level of Helicobacter pylori and Number of Platelets in Non-ITP Patients Who Underwent Gastroscopy

Purpose: To investigate both the presence of H. pylori in non-ITP patients who had not undergone H. pylori eradication, and also its relationship (if any) with the number of platelets. Methods: This retrospective study was performed with a total of 220 cases aged between 18 and 65 years who had undergone gastroscopy. H. pylori levels of the participants were investigated, and concurrently their hemograms were analyzed, and their platelet counts were performed. At the same time, cases in the H. pylori positive arm were compared with subgroups categorized based on their degree of positivity. Results: A statistically significant difference was not detected between platelet counts of the cases based on their H. pylori levels (p = 0.583). A statistically significant difference was detected between H. pylori levels, and distribution of histopathological diagnosis of the cases (p = 0.001; p < 0.01). Conclusion: Our study results revealed that in cases where any primary or secondary factor which might affect platelets is absent, the presence of H. pylori has not any effect on platelet counts.


Introduction
Helicobacter pylori (H. pylori), a gram-negative spiral bacterium that colonizes the human stomach, is globally known as a causative agent of many gastrointestinal diseases and a risk factor for the development of gastric cancer and lymphoma. H. pylori causes one of the most common human chronic infections, being present in the gastric mucosa of more than 50% of the world population [1]. Infection has also been associated to non-digestive diseases such as coronary heart disease, acne rosacea, chronic idiopathic urticaria, hematological disorders, and immune thrombocytopenia (ITP) [2]. The prevalence of H. pylori is variable in the population, reaching up to 80% [2].
Platelets have important roles in hemostasis. The normal platelet count ranges between 100 × 10 9 /L and 450 × 10 9 /L [3]. Circulating lifetime of platelets is ten days and almost 1/3 of platelets are seized in the spleen [3]. Consequently, a continuous balance between production and consumption is essential. Generally defined as a platelet count less than 150 × 10 9 /L, thrombocytopenia is caused by increased destruction or consumption, splenomegaly, and decreased production due to bone marrow suppression or failure [4]. Besides the contribution of age, gender and genetic factors are known to affect the platelet count.
Successful eradication against H. pylori had been increasingly demonstrated to recover platelet counts in patients with ITP [5], and reports on the long-term outcome of this established treatment have been published [6] [7]. In contrast, Matsukawa et al. reported a reduction in platelet counts 8 weeks after the successful eradication therapy for the pathogen in non-ITP patients [8].
The aim of the present study was to investigate both the presence of H. pylori in patients without primary and secondary disease which will affect the number of platelets who had not undergone H. pylori eradication, and also its relationship (if any) with the number of platelets.

Material and Method
Study Design: This retrospective study was performed with a total of 220 cases aged between 18 and 65 years who had undergone gastroscopy. The cases were grouped according to age, gender, histopathological diagnosis (H. pylori positive, and negative), and platelet counts. H. pylori positive patients were subgrouped within themselves as cases with low, moderate, and higher bacterial densities.
Patients with previously known hematologic malignancy, and/or received radiotherapy or chemotherapy for the treatment of these malignancies, cases with disease which primarily and secondarily related to H. pylori infection, patients using drugs which will possibly effect platelet counts, and participants who had used drugs with the intention to eradicate H. pylori were excluded from the study.

Results
A total of 220 patients met the eligibility criteria for the study. Of the 220 patients (147 females, 73 males) whose charts were reviewed, the mean age was 42.93 ± 12.52 (range 18 to 65) years.
Chronic active gastritis was most frequently observed in cases with high H. pylori levels relative to those without (p = 0.001; p < 0.01). Chronic inactive gastritis was observed at significantly higher rates in whom H. pylori was not observed when compared with cases with low, moderate, and high H. pylori levels (p = 0.001; p = 0.001; p = 0.001; p < 0.01). Similarly, in patients who had low H pylori densities, chronic inactive gastritis was detected at statistically significantly higher rates when compared with patients with moderate, and high levels of H. pylori (p = 0.008; p = 0.023; p < 0.05). Chronic superficial gastritis was observed at a significantly lower rate in cases without H. pylori when relative to those with low, and moderate levels of H. pylori (p = 0.015; p = 0.018; p < 0.05). Similarly, chronic superficial gastritis was observed at a remarkably, though not significantly lower when compared with low, and moderate levels of H. pylori (p = 0.084; p = 0.086; p > 0.05) (Table 1) (Figure 1). A statistically significant difference was not detected between H. pylori-negative cases, and cases with lower H. pylori-positivity (p = 0.511; p > 0.05). A statistically significant difference was not found between H. pylori-negative, and moderately positive cases (p = 0.667; p > 0.05). Platelet counts were 16.000/mm 3 higher in H. pylori-negative cases when compared with highly positive-cases  (Figure 2).

Discussion
The aim of our study was to investigate if any correlation exists between H. pylori level, and platelet counts in patients who had undergone gastroscopy, and hadn't any disease which might affect platelet counts. In the literature, many studies have investigated the impact of H. pylori eradication on platelet counts, however any study which evaluated the relationship between platelet counts and H. pylori levels has not been encountered. In the present study, we have found that presence of H. pylori, and degree of positivity were independent from age, and gender. In accordance with the literature, H. pylori was detected most fre- H. pylori eradication therapy. In the comparison between H. pylori-positive, and -negative groups, a statistically significant intergroup difference was not detected (p > 0.05). Among H. pylori-positive cases a statistically significant difference between H. pylori levels, and platelet counts was not found (p > 0.05).
Limitations of our study include the retrospective design and relatively small number of our series. In addition, some details of history and factors that may influence the outcome may not be completely documented. Due to these restric-tions, associations should be interpreted with caution.
Our study results revealed that in cases where any primary or secondary factor which might affect platelets is absent, the presence of H. pylori has not any effect on platelet counts. In our study a statistically significant difference was not observed between presence, and density of H. pylori and platelet counts which supports the assumption suggesting that eradication of H. pylori, and variations in platelet counts might be mediated via another mechanism. Re-evaluation of the relationship between H. pylori infection, and platelet counts, in the light of more detailed parameters, and larger scale studies will provide a reference value which will be required during treatment planning process.