Mycophenolate Mofetil Therapy Is a Steroid Sparing In Childhood and Young Adult Chronic ITP and Evans Syndrome.

Abstract 1441

Chronic ITP and Evans syndrome are diseases characterized by autoantibody formation with resultant destruction of platelets or both platelets and red blood cells on neutrophils, respectively. Affected patients are at risk of life threatening bleeding complications and/or life threatening anemia. Conventional therapies are often ineffective or transiently effective and have significant toxicity. One of the most commonly used therapeutic strategies employs chronic corticosteroid administration with the attendant weight gain, hypertension, hyperglycemia, bone loss, infection risk, mood changes and protean other undesirable side effects. Mycophenolate Mofetil (MMF) is an immunosuppressive agent with a favorable side effect profile. It is converted to the active metabolite, mycophenolic acid, and interferes with purine metabolism in T-lymphocytes, effectively killing many of these cells and down-regulating autoimmune phenomena. With approval of our local IRB /HIC we retrospectively reviewed the charts of 11 chronic ITP/Evans syndrome patients who had received MMF, all such patients treated at a large urban Children's Hospital. Clinical variables included age, sex, duration of disease, steroid use, IVIG use, Anti-D use, platelet counts, hemoglobin concentrations and reticulocyte percentages. These data were analyzed using paired t-tests, one-sample t-test and descriptive statistics. The 11 patients ranged in age from 9–22 years old, with a mean age of 15 years. The mean time from diagnosis of disease was 41.8 months with a range of 6–95 months. There were 5 female subjects, 6 Evans syndrome patients and 5 with chronic ITP alone. The median platelet count over the 6 months prior to MMF was 70×10⁹/L, (18-223), with a median of 90×10⁹/L with (27-145) during the first 6 months of MMF therapy (p=0.4). In the Evans syndrome group, the mean hemoglobin prior to MMF was 10.9 g/dL, (9.1-14.6), with a mean of 12.1 g/dL, (6.9-16.7) on MMF (p=0.54). Similarly, the mean reticulocyte percentage was 2.7%, (0.5-14) prior to MMF, with a mean of 2.3%, (0.3-8.9) during MMF therapy. The mean total dose of steroids used in the 6 months prior to MMF was 84.2 mg/kg (prednisone equivalent), (11.2-170), compared to 62.2 mg/kg, (0-193.8) on MMF. 9 of 11 patients had reductions in steroid requirement by an average of 49.3% (p=0.0013). During the first 6 months of MMF both IVIG and anti-D usage decreased from total doses for the entire group of 17 and 3 doses to 8 and 1 dose, respectively. None of the patients experienced severe bleeding episodes or side effects more serious than a transient rash while on MMF. These data suggest that MMF may have a role as a steroid sparing therapy in the treatment of chronic ITP and Evans syndrome.