Recurrent Infection and Immune Dysfunction: A Case of NCF-2 Gene Mutation with Secondary Hemophagocytic Lymphohistiocytosis

Abstract

A 3-month-old female was referred to our facility for evaluation of recurrent severe infections. Her medical history was rich with frequent hospital admissions for intravenous antibiotic courses, blood transfusions on two separate occasions, and a recent growth of <i>Pseudomonas aeruginosa</i> on bronchoalveolar lavage culture. During inpatient stay, culture-sensitive antibiotics, broad-spectrum antifungals, and blood products were administered. Her blood, urine, and spinal fluid cultures, as well as serum/respiratory viral screening panels, yielded nil. In view of persistent high-grade fever, raised inflammatory markers, and recurrent infections, whole-exome sequencing was performed with the suspicion of an underlying immunodeficiency syndrome and/or primary hemophagocytic lymphohistiocytosis (HLH). A homozygous pathogenic variant <i>c.229C&#x3e;T(p.R77X)</i> in the <i>NCF-2 (neutrophil cytosolic factor 2)</i> gene was detected, with no concurrent primary HLH mutations. Thus, a diagnosis of chronic granulomatous disease with secondary HLH was confirmed. Aggressive continuation of antimicrobial therapy soon led to defervescence, recession of inflammatory markers, and improvement in general wellbeing. Notably, the institution of definitive HLH treatment protocol was not required as the triggering element was targeted. The patient was then repatriated on prophylactic antibiotics with strong recommendation for bone marrow transplantation.