The immunocompromised patients (n = 6, 50% men, median age 62 years) were diagnosed with haematological malignancies (n = 2; pomalidomide plus dexamethasone treated myeloma and untreated chronic lymphocytic leukemia, respectively) and spondyloarthritis (n = 2; both treated with TNF blocking agents and sulfasalazine). Here, TNF is linked to plasma cell myeloma.