Background: The anti-CD 20 monoclonal antibody rituximab depletes B cells and is given to patients with refractory and chronic ITP. Secondary hypogammaglobulinemia have been reported afterwards.
Aim: To evaluate the prevalence of hypogammaglobulinemia in children with ITP after treatment with rituximab.
Methods: The database of the Hematology and Immunology units was searched for children diagnosed with ITP during 2000-2014. Results of serum immunoglobulin levels and clinical details were extracted.
Results: 307 patients were included; twelve were treated with rituximab . Two of them (16.7%), with normal immunoglobulins prior to treatment, had in addition autoimmune hemolytic anemia and developed persistent hypogammaglobulinemia 1 and 2 years following rituximab treatment. One had recurrent respiratory tract infections, and one had generalized lymphadenopathy and granulomatous lung disease. Two of the 295 untreated patients (0.68% ,p=0.008), developed persistent hypogammaglobulinemia:one with recurrent ear and respiratory infections 6 years after ITP diagnosis, the other one presented with necrotizing fasciitis of deltoid muscle after routine vaccination, 4 years after ITP diagnosis.
Conclusions: 1.3% 0f patients with ITP developed persistent hypogammaglobulinemia and clinical features compatible with common variable immunodeficiency. The rate was significantly higher in patients who were treated with rituximab compared to those without rituximab treatment. ITP, especially when accompanied by immune mediated hemolytic anemia, can precede the development of CVID by several years. However, acceleration of this process by rituximab treatment cannot be excluded. Serum immunoglobulins levels should be tested periodically in patients with immune mediated thrombocytopenia, especially in symptomatic patients and after rituximab treatment.
