Pulmonary Involvement in Patients With Hemophagocytic Lymphohistiocytosis

Acquired hemophagocytic lymphohistiocytosis (HLH) is a life-threatening event that usually occurs as a complication of immunodeficiency. Lung involvement in HLH has received little attention. This article describes lung involvement in HLH and assesses whether it affects the prognosis.

We retrospectively studied 219 patients with HLH admitted to a national reference center over a 14-year period, including 118 (54%) with lung involvement.

Dyspnea and cough were the most common onset symptoms. Radiographs revealed interstitial infiltrates with centrilobular nodules, ill-defined consolidation, or localized ground-glass opacities. Pleural effusions and mediastinal lymphadenopathies were found in approximately one-half of the patients. One or more causes of lung involvement were documented in 91 of 118 patients (77.1%) and included infection (n = 52), pulmonary edema (n = 34), and malignancies (n = 22 [mostly lymphoma]). HLH-specific treatment combined with treatment of the cause of lung involvement improved respiratory function in only 67 of the 188 patients (56.7%). Hospital mortality was higher in patients with lung involvement (52.5% vs 20%). Infection as the cause of lung involvement was the only determinant of death (56% vs 30%; P = .004).

Lung involvement is common and of poor prognosis in patients with HLH. Studies should assess whether specific diagnostic and therapeutic strategies are warranted in patients with HLH and lung involvement.