The haematological manifestations of tuberculosis

Abstract

Background: The exact haematological changes present in tuberculosis, pulmonary and extrapulmonary, are still very controversial and have not been adequately investigated. The effect of human immunodeficiency virus (HIV) on these haematological manifestations also remains to be explored since most studies on the haematological effect of tuberculosis were performed in the pre-HIV era. Objective: To evaluate the haematological manifestations of tuberculosis in an evolving HIV era. Methods: Prospective study of consecutively recruited patients (n=125) with microbiologically or histologically proven tuberculosis admitted at Chris Hani Baragwanath Academic Hospital between October 2017 and July 2018. Participants were obtained through the National Health Laboratory Service (NHLS). Demographics and relevant medical history were obtained for all participants and their blood results obtained through the NHLS database. Results: Anaemia was seen in 60.7% of patients with pulmonary tuberculosis (PTB) and 61.1% of extra-pulmonary tuberculosis (ETB) patients (p = 0.964). ETB patients had lower white cell counts (WCC) and lower neutrophil counts than PTB patients, 5.59 [3.6-8.1] vs 7.96 [5.27- 10.34], p = 0.002, and 4.2 [2.1-7.0] vs 5.5 [3.3-8.4], p = 0.079, respectively. Leucocytosis was only seen with PTB. Compared to the HIV seronegative patients, HIV co-infected PTB patients had lower WCC, lymphocyte counts, and neutrophil counts, 6.9 [4.8-9.7] vs 9.4 [8.6- 11.4], p = 0.0037, 0.7 [0.46-1.31] vs 1.51 [1.13-2.05], p = 0.0051, and 4.7 [2.8-7.7] vs 8.5 [5.9- 10.1], p = 0.0106, respectively. Patients co-infected with HIV and tuberculosis had higher levels of WCC, 7.9 [4.6-10.9] vs 5.8 [4.3-8.3], p=0.0465, if they were on combination antiretroviral therapy (cART). Conclusion: Anaemia is still the most common manifestation of tuberculosis. We have highlighted the reactive nature of PTB haematological abnormalities, as compared to ETB based on the presence of higher white cell counts in both HIV seropositive and HIV seronegative patients. HIV can blunt some of the previously described haematological manifestations of tuberculosis such as neutrophilia and lymphocytosis among patients with PTB but does not significantly alter the haematological presentation of ETB.