Lenalidomide-induced hypersensitivity pneumonitis.

symptoms recovered within few days. The transbronchial biopsies in the patients described by Lerch et al. [1] and Thornburg et al. [2] revealed a nonspecific, hypersensitivity pneumonitis (compatible with toxic drug-induced damage). Immunosuppressive therapy with steroids induced a rapid relief of all symptoms in all 3 cases. Infectious cause of the pulmonary infiltrates could be excluded by broncho-alveolar lavage. No eosinophilia was found, as reported in literature in several cases of thalidomide induced pulmonary reactions. Taking the well-tolerated thalidomide pretreatment of the here described patient in consideration, rather a drug-, than a class-specific adverse effect may be suggested. Accordingly, Pretz et al. in 2009 [3] described a 76-year-old female myeloma patient who had developed a thalidomide induced pneumonitis and showed a good tolerance to a subsequent lenalidomide therapy. As described for bortezomib and thalidomide, lenalidomide therapy may cause severe pulmonary side effects in rare cases. The pathomechanism remains unclear, a toxic or immunologically mediated mechanism can be envisaged. Physicians prescribing lenalidomide should be aware of this rare but severe pulmonary complication, and should consider a lenalidomide induced hypersensitivity pneumonitis if patients develop a pulmonary affection during lenalidomide therapy. Especially in patients not responding to antibiotic therapy a broncho-alveolar lavage and if possible a transbronchial biopsy are recommended to document a hypersensitivity reaction which should be treated by steroids and to exclude an infectious disease. In these patients further exposition to lenalidomide may be harmful, potential alternatives should be considered.