Diagnostic accuracy and clinical role of rapid C-reactive protein testing in HIV-infected individuals with presumed tuberculosis in South Africa

Abstract

Objective We sought to determine the accuracy and role of rapid C-reactive protein (CRP) testing in HIV-infected tuberculosis suspects. Design We enrolled HIV-infected adults (≥18 years) with a cough for ≥2 weeks and negative sputum smears for acid-fast bacilli (AFB) in KwaZulu-Natal, South Africa. Participants were evaluated for pulmonary tuberculosis by a nurse with rapid CRP, and independently by a physician with a chest radiograph. Rapid CRP test results were compared to laboratory CRP and sputum sent for confirmation of tuberculosis. Results Among 93 participants, 55 (59%) were female, mean age was 35 years, and median CD4 count was 177/mm3. Forty-five (54%) participants were diagnosed with pulmonary tuberculosis. Diagnostic sensitivity and specificity were 95% (95% CI 74–99%) and 51% (95% CI 35–66%) for rapid CRP > 8 mg/l, 87% (95% CI 73–96%) and 53% (95% CI 38–68%) for nurse assessment, and 69% (95% CI 52–83%) and 76% (95%CI 61–87%) for physician examination. Combining a positive rapid CRP (> 8 mg/l) to nurse and physician assessments decreased post- test probability of pulmonary tuberculosis from 22% to 6% and 32% to 6%, respectively. Conclusion Rapid CRP testing helped exclude pulmonary tuberculosis, and may be a valuable test to assist nurses and physicians in tuberculosis-endemic regions.

Diagnostic accuracy of C-reactive protein for active pulmonary tuberculosis: a meta-analysis

“…One study evaluated two different CRP assays (POC sandwich vs. lab-based immunoturbidometric assay) within the same study population and found no differences in their diagnostic accuracy for pulmonary TB. 28 To avoid underestimating heterogeneity, we included accuracy data obtained from only the POC assay. 28 None of the included studies reported enrolling pediatric patients.…”

“…28 To avoid underestimating heterogeneity, we included accuracy data obtained from only the POC assay. 28 None of the included studies reported enrolling pediatric patients.…”

“…Most studies were designed to evaluate the diagnostic accuracy of CRP for pulmonary TB. 8,9,22,28 All studies selected patients either consecutively or by random sample. 8,9,17,22,28 Two studies enrolled a representative spectrum of patients 8,9 while three studies restricted enrollment to patients with a high probability of pulmonary TB ( e.g.…”

Latent tuberculosis infection – Revisiting and revising concepts

“…A number of assays are available to measure this because of the use of CRP in cardiovascular disease. In a recent study, rapid CRP >8 mg/dl had a sensitivity of 95% and specificity of 51% for the diagnosis of TB in symptomatic HIV-infected persons with negative sputum smears [141]. Neopterin is produced by activated macrophages and dendritic cells.…”

Host-Based Diagnostics for Detection and Prognosis of Infectious Diseases

“…Despite its discovery in 1930 (Tillett & Francis, 1930), CRP continues to be investigated for its diagnostic and prognostic utility. Recent examples include periprosthetic joint infection (Deirmengian et al, 2014), urinary tract infections (Xu, Liu, Liu, & Dong, 2014), tuberculosis in HIV patients (Drain et al, 2014), and as an early predictor of infective complications in laparoscopic colorectal surgery (Nason et al, 2014).…”