Adenovirus-associated HLH with coronary involvement

A 2-year-old boy was treated in the outpatient clinic for a febrile illness associated with cough and cold. However, these therapies failed. He also exhibited increasing respiratory rates. The child had been generally healthy since birth.

The boy was immediately hospitalized; adenovirus was detected on the upper respiratory Biofire test. The fever persisted despite bronchodilators and fluids. This prompted an echocardiogram on day five – revealing significant coronary artery dilation without Kawasaki disease features. Treatment included intravenous immunoglobulin (IVIG), but respiratory distress necessitated transfer to the pediatric intensive care unit (PICU).

Here, the child received heated, humidified high-flow oxygen (HHHFNC). However, hepatosplenomegaly was detected; on chest X-ray, there was a dense consolidation in the left lower zone. Further, the C-reactive protein and procalcitonin levels were elevated. Antibiotics (vancomycin, meropenem) were initiated. 

Subsequent echocardiography showed dilated coronary arteries, and the child was commenced on high-dose aspirin and inj. methylprednisolone. Persistent fever directed a work-up for hemophagocyticlymphohistiocytosis (HLH)––which revealed bicytopenia, hyperferritinemia, and hypertriglyceridemia. The child received IVIG, methylprednisolone, and sc. inj. anakinra. 

On day four of anakinra, echocardiography showed improvement, but the child remained febrile and HHHFNC-dependent. Anakinra was continued, and steroids were switched to IV hydrocortisone. Yet, the child became afebrile on day six of anakinra; HRCT revealed lung consolidation. After one week of anakinra, the dose was reduced, and the child remained afebrile. Anakinra was ceased after day ten. Whole exome sequencing found no genetic evidence of primary HLH.

Follow-up investigations showed decreasing inflammatory markers, and echocardiography revealed a small aneurysm in the proximal left anterior descending artery. The child was gradually weaned off steroids and antibiotics, was discharged after a month from admission, and continued aspirin – six months post-discharge.

Anakinra, rather than etoposide, was chosen due to the lower sepsis risk. In this case, anakinra exhibits efficacy in treating secondary HLH – emphasizing its potential as a first-line agent. The case highlights the unique aspect of adenovirus-associated HLH with coronary involvement, underscoring the consideration of anakinra as a treatment option in such cases.

Source: Chowdhury P, Saha S, Meur S. Indian Pediatrics. 2023 Dec;60(12):1041-2.