University of Campinas, Hematology and Hemotherapy Center, Campinas, Brazil.
Department of Clinical Pathology, School of Medical Sciences, University of Campinas, Campinas, Brazil.
J Thromb Haemost. 2021 Sep;19(9):2275-2286. doi: 10.1111/jth.15396. Epub 2021 Aug 9.
The optimum second-line treatment or best sequence of treatments for immune thrombocytopenia (ITP) are yet to be determined. Our institution has accumulated extensive experience regarding the use of dapsone as second-line therapy for ITP.
We aimed to assess the efficacy rate and safety of dapsone treatment in ITP patients.
PATIENTS/METHODS: Here we report our experience in a retrospective study, including 122 patients, with a median treatment duration with dapsone of 6 months and a median follow-up period of 3.4 years.
The overall response rate in this cohort was 66%, including 24% of complete responses. Among responders, in 24% a relapse occurred while on treatment. Therefore, a sustained response was observed in 51% of patients. Interestingly, 81% of the responders maintained the response after the interruption of treatment, for a median time of 26 months. Side effects were reported in 16% of the patients in this cohort and treatment was interrupted due to side effects in 11% of patients. The main cause in these cases was hemolytic anemia and methemoglobinemia. Reductions in hemoglobin levels during the use of dapsone were seen in 94% of the patients. Responders presented significantly greater reductions in their hemoglobin levels than nonresponders did: median hemoglobin drop of 1.9 g/dl vs. 1.2 g/dl (p = .004).
Our findings suggest that dapsone has adequate efficacy and is well tolerated. Although the mechanism of action is still unclear, our observation that the degree in the drop of hemoglobin is greater in responders suggest a possible role of the blockage of the reticuloendothelial system in the therapeutic effect of the drug.
免疫性血小板减少症（ITP）的最佳二线治疗或最佳治疗顺序尚未确定。我们机构在使用氨苯砜作为 ITP 的二线治疗方面积累了丰富的经验。
评估氨苯砜治疗 ITP 患者的疗效和安全性。
患者/方法：在此，我们报告了一项回顾性研究的经验，该研究包括 122 例患者，氨苯砜的中位治疗时间为 6 个月，中位随访时间为 3.4 年。
该队列的总体缓解率为 66%，包括 24%的完全缓解。在缓解者中，24%的患者在治疗过程中复发。因此，51%的患者观察到持续缓解。有趣的是，81%的缓解者在停药后仍能维持缓解，中位时间为 26 个月。该队列中有 16%的患者出现了不良反应，11%的患者因不良反应而中断了治疗。这些情况下的主要原因是溶血性贫血和高铁血红蛋白血症。在使用氨苯砜期间，94%的患者血红蛋白水平下降。缓解者的血红蛋白水平下降幅度明显大于无缓解者：中位血红蛋白下降 1.9 g/dl 比 1.2 g/dl（p = 0.004）。
我们的研究结果表明，氨苯砜具有足够的疗效且耐受性良好。尽管其作用机制尚不清楚，但我们观察到缓解者的血红蛋白下降幅度更大，这表明其阻断网状内皮系统可能在药物的治疗效果中起作用。
