Hemophagocytic lymphohistiocytosis (HLH) secondary to tuberculosis: A case series.

Hemophagocytic lymphohistiocytosis (HLH) is an exaggerated but ineffective immune response secondary to infections, inflammatory conditions, or malignancies. HLH is characterized by macrophage and T-cell activation resulting in phagocytosis of erythrocytes, lymphocytes, and platelets and an exuberant cytokine response respectively leading to catastrophic systemic manifestations. The clinical and biochemical profile of HLH significantly overlaps with that of sepsis, which may lead to misdiagnosis. Tuberculosis (TB) is an important infectious cause of HLH with a reported mortality of more than 50%. HLH may be misdiagnosed in patients with tuberculosis as the reticuloendothelial system is extensively involved in both disseminated TB and HLH. We present a series of four cases of TB-HLH admitted to the respiratory intensive care unit in a tertiary care hospital.