Tuberculosis-Associated HLH in an 8-Month-Old Infant: A Case Report and Review

Area of Science:

• Pediatrics
• Immunology
• Infectious Diseases

Background:

• Hemophagocytic lymphohistiocytosis (HLH) is a severe immune dysregulation syndrome that can be triggered by infections.
• Tuberculosis (TBC) is an uncommon but significant infectious trigger for secondary HLH, particularly in infants.
• Distinguishing HLH from sepsis in infants is challenging due to overlapping clinical presentations.

Observation:

• An 8-month-old infant presented with prolonged fever, pancytopenia, and acute respiratory failure, initially suspected as sepsis.
• Bone marrow biopsy confirmed hemophagocytosis, and familial HLH work-up was negative.
• Despite initially negative microscopy and PCR, a positive interferon-gamma release assay prompted empiric anti-tuberculous therapy, leading to TBC confirmation.

Findings:

• The infant was successfully treated with extracorporeal membrane oxygenation (ECMO) for 28 days for TBC-associated HLH-induced acute respiratory failure.
• Disseminated TBC lesions were identified, and the infant's mother was the source of infection.
• The child recovered with mild fine motor skill sequelae.

Implications:

• This case highlights the importance of considering tuberculosis (TBC) in the differential diagnosis of infants presenting with suspected septicemia and HLH, even with initially negative microbiological tests.
• Successful management of TBC-associated HLH in infants may involve supportive care like ECMO.
• Early diagnosis and treatment of TBC are critical to prevent severe outcomes like acute respiratory failure in infants with HLH.