[Rituximab treatment for adults with steroid-resistant idiopathic thrombocytopenic purpura].

OBJECTIVE

To investigate the efficacy and safety as well as the effects of rituximab on B-lymphocytes and anti-platelet glycoprotein-specific antibodies, in patients with steroid-resistant idiopathic thrombocytopenic purpura (ITP).

METHODS

Twelve steroid-resistant ITP patients, 16 to 54 years old, received intravenous rituximab at the dose of 375 mg/m2 once--weekly for 4 weeks. Lab studies included CBC, serum concentrations of IgG, IgM and IgA. CD3+, CD4+, CD8+, CD19+, CD20+ cell numbers were assayed by flow cytometry and anti-platelet glycoprotein-specific antibodies (GP IIb/IIa, GP Ib/IX) were assayed by monoclonal antibody-specific immobilisation of platelet antigens prior to and following rituximab therapy.

RESULTS

A complete response (platelet counts > or = 100 x 10(9)/L) was observed in 4 cases, a partial response (platelet counts between 50 and 100 x 10(9)/L) in 3 cases, a minor response (platelet counts between 30 and 50 x 10(9)/L) in 2 cases, and nonresponse (platelet counts < 30 x 10(9)/L) in 3 cases. Responses were sustained 0.5 to 12 months (median 5 months). After 4 weeks of rituximab therapy, anti-platelet glycoprotein-specific antibodies (GP IIb/IIIa, GP Ib/IX) disappeared except one NR patient and CD19+/ CD20+ cells were almost depleted in all patients (295.0 +/- 86.4) x 10(6)/L vs (4.1 +/- 2.2) x 10(6)/L (P < 0.01). As expected, the T cell counts, and the serum concentrations of IgG, IgM and IgA were not changed after therapy. No severe side effects were observed.

CONCLUSION

Rituximab may be an effective and safe treatment for adults with steroid-resistant ITP.