Erythrocyte sedimentation rate at diagnosis in culture positive cases of active tuberculosis

Objective: To evluate the Erythocyte Sedimentation Rate (ESR) at the time of diagnosis in culture positive cases of different types of active tuberculosis (TB). Methodology: In this retrospective descriptive study conducted at King Abdulaziz Medical City, Riyadh, Saudi Arabia, ESR was done by a modified Westergren method using a rapid test. Cases of active TB (defined as a case of TB up to two weeks from the start of anti-tuberculous treatment), were evaluated for ESR at the time of diagnosis. Results: Of 246 cases of culture positive TB, ESR results during active phase were available in 195 (79.3%) patients. Number (%) of patients with pulmonary, extra-pulmonary and disseminated TB were 69 (35%), 78 (40%) and 49 (25%) respectively. Two (1%) of these patients were HIV positive. ESR was elevated in 169 (87%) and was normal in 26 (13%) patients. Mean ESR in all patients was 67.6 mm/hr with no statistical difference between patients with different TB types. ESR between 1-30, 31-60, 61-90, 91-120 and 121-150 mm/hr represented 19%, 23%, 23%, 19% and 6% of the cases respectively, whereas 44 (22.6%) of the patients had ESR more than 100 mm/hr. Conclusion: In HIV negative patients with suggestive features of TB but without any other underlying disease affecting the ESR, the baseline ESR may be a valuable diagnostic test to suspect TB in resource poor countries.