Direct antibody test negative autoimmune hemolytic anemia with pulmonary tuberculosis: A diagnostic challenge

Tuberculosis (TB) has varied manifestations, but autoimmune hemolytic anemia (AIHA) due to TB is rare. Direct antibody test (DAT) or Coombs negative AIHA is also rare. We report a case of a 14-year-old boy who presented with hemolytic anemia and pneumonia. The Coombs test was repeatedly negative. After ruling out the possible infectious and noninfectious causes by extensive investigations, he was diagnosed as DAT-negative AIHA by monospecific antibody test with 4°C low ionic strength saline washes and column agglutination method which revealed the presence of IgG-2+ antibodies. Bronchoalveolar lavage fluid for acid-fast bacilli and gene Xpert was also positive. It is important to recognize TB as a cause of AIHA in South Asian countries where its incidence is high.