SEVERE NEUTROPENIA ASSOCIATED WITH IGG2 SUBCLASS DEFICIENCY AND BONE-MARROW T-LYMPHOCYTE INFILTRATION

Patients with selective IgG2 subclass deficiency (IgG2 SD) usually suf fer from recurrent respiratory infections, The occurrence of cytopenia is extremely rare in these patients. We report on two patients with i solated IgG2 SD who experienced unexplained severe neutropenia associa ted with T-lymphocyte proliferation, IgG2 SD clearly preceded the occu rrence of neutropenia in one patient, In the other patient, the long-s tanding history of recurrent respiratory infections prior to diagnosis of agranulocytosis suggests that IgG2 SD also preceded the occurrence of neutropenia, Analysis of bone marrow biopsy in both patients and s kin tissue lesions in one patient showed massive infiltration with CD4 + and CD8+ T-lymphocytes, The pathological feature did not suggest any malignant lymphoproliferative disorder, Neutropenia was refractory to i.v. Ig in both patients and to recombinant G-CSF, steroids, and cycl ophosphamide in one patient, Severe cellulitis led to death in one pat ient, In summary, we reported herein a heretofore undescribed syndrome characterized by the association of IgG2 SD with severe neutropenia a nd tissue T-cell infiltration. It suggests that bone marrow analysis a s well as determination of serum IgG subclasses need to be performed i n patients with unexplained neutropenia. (C) 1998 Wiley-Liss, Inc.