Iatrogenic IgG2 deficiency in a leukaemic child. A case report.

A girl with acute non-lymphoblastic leukaemia was treated with immunosuppressive chemotherapy. After cessation of therapy she had three consecutive episodes of infection due to Streptococcus pneumoniae from which she recovered and was shown to have developed a combined deficiency of both IgG2 and IgG4. The patient eventually relapsed and died 3 years after the initial diagnosis. The importance of measuring IgG subclasses in patients treated with immunosuppressive chemotherapy is discussed.