Chemotherapy in patients with pulmonary Langerhans cell histiocytosis

Pulmonary Langerhans cell histiocytosis (PLCH) is a rare disorder, affecting mainly young adult smoker. The aim of this study was to present the results of cladribine (2-CdA) treatment in patients with PLCH. Patients and method: This retrospective analysis included 12 patients (7 females and 5 males; aged mean 40.08 ± 6.7 years) with LCH treated with 2-CDa in years 2010 to 2017. Eight patients had multi system and 4 isolated pulmonary LCH. Patients received 2 to 6 courses of 2-CdA, as a single agent in a dose of 0.15 mg/kg per day/ iv. for 5 consecutive days at monthly intervals. Results: Treatment resulted in improvement or stabilisation of pulmonary function parameters in 5(36%) and 7(64%) patients respectively. Two patients with bone lesions, one with abdominal changes and one woman with infiltration in vertebra and in periaortic space experienced partial regression and disease was not active. Treatment related toxicities were: upper respiratory tract infections grade 2 in 7(64%) patients, and grade 3 in 2(18%), leukopenia grade 1 in 3(25%), grade 2 in 4 (33%), grade 3 in 1(9%) patients, lymphopenia grade 1 in 3(25%), grade 2 in 7(64%), and grade 3 in 2(18%) patients, thrombocytopenia grade 1 in 2(17%), grade 2 in 1(9%), grade 4 in one (9 %) patient, anaemia grade 4 and 2 in one (9%) patient respectively. There was no case of LCH progression. During observation (mean 111.5 ± 59.22 months), one patient suddenly died with unknown cause, other one developed chronic myelogenic leukaemia. No reactivation of the disease has been noticed. Conclusion: Cladribine as a single agent is an effective therapy in adult patients with progressive PLCH but was mainly resulted in stabilization of pulmonary function.