TITLE:
C-Reactive Protein as a Triage Test in Guiding Who Should Get a Confirmatory Test for Pulmonary Tuberculosis Diagnosis among Adults: A Case-Control Proof-of-Concept Study from Urban Tanzania
AUTHORS:
Evarist Chiweka, Thomas Maroa, Hosiana Temba, Joseph Ponera, Sharifa Athumani, Lujeko Kamwela, Mohamed Sasamalo, Rastard Naftari, Mirambi Tito, Francis Mhimbira, Jerry Hella
KEYWORDS:
C-Reactive Protein, Pulmonary Tuberculosis, Screening, Temeke, Tanzania
JOURNAL NAME:
Journal of Tuberculosis Research,
Vol.10 No.1,
March
25,
2022
ABSTRACT: Background:
The current screening tools for tuberculosis (TB) are inadequate resulting in
insufficient TB case detection and continued community transmission of TB. As the
world is geared into finding missing TB cases, new strategies are called for to
aid in rapid identification of TB cases. This study aimed to evaluate the role
C-reactive protein (CRP) in triaging patients to get a definitive test for active pulmonary TB diagnosis in urban
Tanzania. Methods: A case-control study was conducted among pulmonary TB (PTB) patients and
contacts without active PTB. The diagnosis of PTB was performed using GeneXpert
MTB/RIF assay and culture. Blood was collected from cases and controls for
measuring CRP levels during recruitment. We compared socio-demographic
characteristics, clinical and laboratory parameters obtained during recruitment
and performed diagnostic accuracy analyses for CRP. Results: Out of all 193
study participants who were involved in final analysis, 147 (76.2%) were males.
Pulmonary TB cases had significantly lower median BMI than controls (median
17.4 kg/m2 [IQR: 15.8 - 19.2 kg/m2] vs., 24.9 kg/m2 [IQR: 22.1 - 28.5 kg/m2), p i.e., 13.33% vs., 11.7%, p = 0.48. CRP was significantly higher in PTB cases vs., controls (median
67.8 mg/L, [IQR: 36.5 - 116.9 mg/L] vs., 1.55 mg/L, [IQR: 0.59 - 6.0 mg/L], p = 0.003). Furthermore, CRP at cut-off ≥10
mg/L was associated with best combination of sensitivity, specificity and area
under the curve of 89.9%, 95% CI: 82.2 - 95.0, 80.9%, CI: 71.4 - 88.2 and 0.85,
95% CI: 0.80 - 0.90 respectively. A multivariate logistic regression model adjusted for
fever, night sweats and body mass index showed that CRP above 10 mg/L was
significantly associated with PTB, aOR 5.2, 95% CI 1.2 - 22.8. Conclusions: CRP
at cut-off ≥10 mg/L can be used to screen pulmonary TB. These findings can be
used to improve TB screening algorithm by
incorporating CRP in combination with TB symptoms to identify patients
who need further confirmatory TB tests. However, additional prospective studies
are required to support our findings and contribute into policy recommendations
on use of CRP in a screening algorithm for pulmonary TB.