A pilot study of memory B lymphocytes in relapsed immune-related pancytopenia patients.
BACKGROUND
Relapse of immune-related pancytopenia (IRP) has often occurred and is very difficult to cure; the pathogenesis of relapsed IRP was unclear. The aim of this work is to investigate whether memory B lymphocytes (Bm) in bone marrow were involved in pathogenesis of relapsed IRP.


METHODS
Seventy-nine patients with IRP (26 untreated, 32 relapsed, and 21 remittent after relapsed) were assessed, the category and the titer of autoantibodies on bone marrow mononuclear cell (BMMNC-Ab), Bm (CD19+CD27+) cells, and activated Bm (CD19+CD27+HLA-DR+) cells in bone marrow were detected by fluorescence-activated cell sorting (FACS).


RESULTS
The percentages of Bm cells (CD19+CD27+/CD19+) and activated Bm cells (CD19+CD27+HLA-DR+/ CD19+CD27+) were 34.73 +/- 11.93% and 69.46 +/- 25.22%, respectively, which were significantly higher than those of untreated IRP (4.73 +/- 0.85%, 12.47 +/- 8.29%) and remittent after relapsed IRP (1.32 +/- 3.52%, 4.35 +/- 6.61%) correspondingly (p < 0.05). The majority of BMMNC-Ab in relapsed patients were IgG (75%), and the positive rates and the titers of IgG autoantibody of relapsed IRP were significantly more elevated than those of untreated IRP (p < 0.05). The positive rate of IgM autoantibody in patients with untreated IRP was 69.23%, and the titer was 28.38 +/- 28.00%, but no significant differences were found in the positive rate and titers of IgM between untreated IRP and relapsed IRP (p > 0.05).


CONCLUSIONS
In patients with relapsed IRP, Bm cells in bone marrow were increased and hyperactive. The predominant autoantibody was IgG. These findings suggest that autoreactive Bm cells may be involved in the pathogenesis of relapsed IRP.
Yi-Hao
YH
Wang
Rong
R
Fu
Zong-Hong
ZH
Shao
D000293:Adolescent; D000328:Adult; D000368:Aged; D016175:B-Lymphocyte Subsets / Q000276:immunology* / Q000473:pathology*; D001854:Bone Marrow Cells / Q000276:immunology / Q000473:pathology; D002648:Child; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007156:Immunologic Memory; D008297:Male; D008875:Middle Aged; D010198:Pancytopenia / Q000276:immunology* / Q000473:pathology*; D010865:Pilot Projects; D012008:Recurrence; D055815:Young Adult