Childhood Langerhans cell histiocytosis with severe lung involvement: a nationwide cohort study.

BACKGROUND: Lung involvement in childhood Langerhans cell histiocytosis (LCH) is infrequent and rarely life threatening, but occasionally, severe presentations are observed. METHODS: Among 1482 children (< 15 years) registered in the French LCH registry (1994-2018), 111 (7.4%) had lung involvement. This retrospective study included data for 17 (1.1%) patients that required one or more intensive care unit (ICU) admissions for respiratory failure. RESULTS: The median age was 1.3 years at the first ICU hospitalization. Of the 17 patients, 14 presented with lung involvement at the LCH diagnosis, and 7 patients (41%) had concomitant involvement of risk-organ (hematologic, spleen, or liver). Thirty-five ICU hospitalizations were analysed. Among these, 22 (63%) were secondary to a pneumothorax, 5 (14%) were associated with important cystic lesions without pneumothorax, and 8 (23%) included a diffuse micronodular lung infiltration in the context of multisystem disease. First-line vinblastine-corticosteroid combination therapy was administered to 16 patients; 12 patients required a second-line therapy (cladribine: n = 7; etoposide-aracytine: n = 3; targeted therapy n = 2). A total of 6 children (35%) died (repeated pneumothorax: n = 3; diffuse micronodular lung infiltration in the context of multisystem disease: n = 2; following lung transplantation: n = 1). For survivors, the median follow-up after ICU was 11.2 years. Among these, 9 patients remain asymptomatic despite abnormal chest imaging. CONCLUSIONS: Severe lung involvement is unusual in childhood LCH, but it is associated with high mortality. Treatment guidelines should be improved for this group of patients: viral infection prophylaxis and early administration of a new LCH therapy, such as targeted therapy.

Long-term follow-up of children with risk organ-negative Langerhans cell histiocytosis after 2-chlorodeoxyadenosine treatment.

The nucleoside analogue, 2-chlorodeoxyadenosine (2CDA), was reported to be an active treatment for childhood Langerhans cell histiocytosis (LCH) without risk organ (RO-) involvement. However, we lack data on long-term effects of 2CDA treatment, including the disease reactivation rate, permanent sequelae and long-term tolerance. This study included 44 children from the French LCH registry, treated for a RO- LCH with 2CDA monotherapy (median number of six courses). The median age at the beginning of 2CDA was 3·6 years (range, 0·3-19·7 years) and the median follow-up after was 5·4 years (range, 0·6-15·1 years). Objective response to 2CDA was observed in 25 patients (56·8%), while six patients (13·6%) had stable disease and 13 patients (29·5%) exhibited progressive disease. Among patients without progression, only two experienced disease reactivation after 2CDA discontinuation. The five-year cumulative incidence of disease progression or reactivation after 2CDA therapy initiation was 34·3%. The lymphopenia reported in all cases [72% below absolute lymphocyte count (ALC) of 0·5 G/l], was addressed with appropriate prophylactic measures. Other toxicities above grade 2 were uncommon, and no second malignant neoplasm or neuropathy was reported. The five-year overall survival was 97·7%. In conclusion, we could confirm that 2CDA monotherapy was a beneficial long-term therapy for treating patients with RO- LCH. Appropriate management of induced immune deficiency is mandatory.

Management and long-term outcomes of sarcoidosis-associated pulmonary hypertension.

Studies reporting the effects of modern strategies with pulmonary arterial hypertension (PAH)-targeted therapies in sarcoidosis-associated pulmonary hypertension (S-APH) are limited.Clinical and haemodynamic data from newly diagnosed patients with severe S-APH (mean pulmonary artery pressure (mPAP) >35 mmHg or mPAP 25-35 mmHg with cardiac index <2.5 L·min-1·m-2) were collected from the French Pulmonary Hypertension Registry between 2004 and 2015.Data from 126 patients with severe S-APH were analysed (mean±sd age 57.5±11.6 years, 74% radiological stage IV). 97 patients (77%) received PAH-targeted therapy and immunosuppressive therapy was initiated or escalated in 33 patients at the time of pulmonary hypertension diagnosis. Four months after PAH-targeted therapy initiation, mean±sd pulmonary vascular resistance decreased from 9.7±4.4 to 6.9±3.0 Wood units (p<0.001), without significant improvement in exercise capacity. Among the 11 patients treated only with immunosuppressive therapy, a haemodynamic improvement was observed in four patients, including two with compressive lymph nodes. After a median follow-up of 28 months, 39 patients needed PAH-targeted therapy escalation, nine underwent lung transplantation and 42 had died. Survival at 1, 3 and 5 years was 93%, 74% and 55%, respectively.PAH-targeted therapy improved short-term pulmonary haemodynamics in severe S-APH without change in exercise capacity. Immunosuppressive therapy improved haemodynamics in selected patients. Pulmonary hypertension in sarcoidosis remains associated with a poor prognosis.