[Recurrent upper respiratory tract infections during and after rituximab therapy]

Rituximab maintenance therapy is indicated for the treatment of patients with non-Hodgkin's lymphoma (NHL) who responded to induction therapy. More than 10% of patients will develop rituximab-induced upper respiratory tract infections (URTIs). These infections are usually mild in patients receiving first-line or second-line treatment. Heavily pretreated patients sometimes undergo additional rituximab maintenance therapy. We describe three female patients aged 53, 43 and 42 years who were successfully treated with rituximab maintenance therapy after chemotherapy for three or more recurrences of NHL. These patients developed more serious recurrent URTIs due to rituximab-induced long-term hypogammaglobulinaemia. In one patient, serum IgG levels continued to decline for four years after rituximab therapy. Long-term immunoglobulin substitution was needed to treat these patients. Physicians should be aware that URTIs may develop in heavily pretreated patients even years after rituximab maintenance therapy and substitution with immunoglobulin may be warranted.