Deficiency of glycosylphosphatidyl inositol-anchored proteins in patients with aplastic anaemia does not affect response to immunosuppressive therapy.
Deficient expression of glycosylphosphatidyl inositol (GPI)-anchored proteins in aplastic anaemia (AA) patients has previously been reported to be associated with a poor response to immunosuppressive (IS) therapy. Here we report the response to IS therapy of 111 patients with AA and correlate this with GPI-anchored protein expression on peripheral blood cells by flow cytometry. A GPI-anchored protein deficient population was identified in 15% (17/111) of patients with AA who had a negative Ham's test and no laboratory evidence of haemolysis. Patients were treated with antilymphocyte globulin and/or cyclosporin A, or oxymetholone. Bone marrow transplantation was performed in 12 patients, seven of whom had not responded to IS therapy. In patients tested for CPI-anchored protein expression prior to IS therapy there was no difference in response rate to IS therapy between AA patients with a GPI-anchored protein deficiency and those with normal GPI-anchored protein expression (50% response rate versus 75%, respectively). Survival in these two groups was similar at 90% with follow-up over 140 months from diagnosis. Eight of the 17 AA patients who developed a GPI-anchored protein-deficient population later went on to develop a positive Ham's test. From this study we demonstrate a lower incidence of GPI-anchored protein deficiency in AA patients compared with previous reports. In addition we have shown that the presence of a GPI-anchored protein-deficient cell population in patients with AA who have a negative Ham's test is not a poor prognostic factor in terms of response and survival after IS therapy.
De Lord
C
C
Department of Cellular and Molecular Sciences, St George's Hospital Medical School, London.
Tooze
J A
JA
Saso
R
R
Marsh
J C
JC
Gordon-Smith
E C
EC
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000741:Anemia, Aplastic / Q000378:metabolism* / Q000628:therapy; D016026:Bone Marrow Transplantation; D002648:Child; D005260:Female; D017261:Glycosylphosphatidylinositols / Q000172:deficiency*; D006801:Humans; D007165:Immunosuppression Therapy; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D015996:Survival Rate
D017261:Glycosylphosphatidylinositols