Severe Evans Syndrome at the Infection-Inflammation-Autoimmunity Interface During Bacteriologically Confirmed Pulmonary Tuberculosis: A Case Report

Evans syndrome is a rare autoimmune cytopenia combining autoimmune hemolytic anemia and immune thrombocytopenia. Active pulmonary tuberculosis creates an inflammatory setting in which anemia of inflammation, bleeding, coagulation abnormalities, marrow involvement, and treatment toxicity can mimic or amplify cytopenia, making attribution to immune destruction difficult.

A 49-year-old man with smear-, Xpert MTB/RIF-, and culture-confirmed drug-susceptible post-primary pulmonary tuberculosis developed diffuse cutaneous bleeding, a hemoglobin nadir of 27 g/L, and a platelet nadir of 1×10⁹/L. Warm autoimmune hemolysis was supported by a strongly positive direct antiglobulin test and a pan-reactive warm eluate with compatible hemolysis markers. The platelet component showed increased turnover, poor post-transfusion increments, and compensatory megakaryocytic hyperplasia. Because the glycoprotein-specific platelet-autoantibody assay was negative, immune thrombocytopenia remained a clinical diagnosis supported by the overall pattern and exclusion of major competing causes. Focused evaluation of an isolated APTT prolongation showed sustained correction on immediate and incubated mixing, no factor VIII, IX, or XI deficiency, no factor VIII inhibitor, and no significant anti-Xa activity. A separate flow-cytometric assay did not detect rifampicin-dependent platelet reactivity. Anti-tuberculosis therapy was continued while glucocorticoids, recombinant human thrombopoietin, transfusion support, and organ support were administered. Counts recovered during combined treatment, tuberculosis therapy was completed, and hematologic remission persisted for 12 months.

Severe infection-associated inflammation can coexist with and obscure autoimmune cytopenia. In this case, convergent evidence established warm autoimmune hemolysis, whereas the immune thrombocytopenia component was diagnosed clinically after exclusion of major competing explanations rather than by definitive platelet serology. The case supports a structured, parallel evaluation of infection, immune cytopenia, consumptive processes, marrow disease, and treatment-related causes without inferring that tuberculosis directly caused Evans syndrome.