免疫性血小板减少症(ITP)可导致膜性肾病(MN)。这里,我们报道了一例MN并发ITP的病例,并通过免疫球蛋白(Ig)G亚类和抗磷脂酶A2受体(PLA2R)抗体的免疫荧光分析,验证了循环抗血小板抗体导致MN的假设.一名39岁的日本男子患有ITP,他已经用泼尼松龙治疗了10个月,病情稳定。然而,4个月后逐渐减少剂量到10毫克泼尼松龙,他患上了肾病综合征,尿蛋白与肌酐之比(U-PCR)为10.6g/gCr,入院。他的血小板计数,在89,000/μL时,低于正常范围,提示ITP复发。肾活检显示肾小球基底膜增厚,IgG和补体成分3沉积。IgG1的主要沉积和抗PLA2R染色的阴性表明继发性MN;然而,没有明显的继发性MN的典型条件。虽然口服泼尼松龙和环孢素A,他难以治疗。总共12次低密度脂蛋白单采术(LDL-A)将他的U-PCR降低至<3g/gCr。出院后七个月,他的U-PCR进一步降低至0.54g/gCr,血小板计数恢复至>200,000/μL。我们的文献综述表明,这种情况对类固醇治疗是难治性的。LDL-A可有效治疗耐药MN并发ITP。
Immune thrombocytopenia (ITP) may lead to membranous nephropathy (MN). Here, we report a
case of MN complicated by ITP and validate the hypothesis that circulating antiplatelet antibodies cause MN using immunofluorescence analysis for immunoglobulin (Ig) G subclass and anti-phospholipase A2 receptor (PLA2R) antibodies. A 39-year-old Japanese man with ITP, who had been treated with prednisolone for 10 months, achieved a stable disease condition. However, 4 months after tapering the dose down to 10 mg prednisolone, he developed nephrotic syndrome, with a urinary protein-to-creatinine ratio (U-PCR) of 10.6 g/g Cr and was admitted to our hospital. His platelet count, at 89,000/μL, was lower than the normal range, indicating the recurrence of ITP. Renal biopsy revealed the thickening of the glomerular basement membrane with the deposition of IgG and complement component 3. Predominant deposition of IgG1 and negativity for anti-PLA2R staining indicated secondary MN; however, no typical conditions of secondary MN were evident. Although oral prednisolone and cyclosporine A were administered, he was refractory to treatment. A total of 12 sessions of low-density lipoprotein apheresis (LDL-A) decreased his U-PCR to < 3 g/g Cr. Seven months after discharge, his U-PCR further decreased to 0.54 g/g Cr and platelet count recovered to > 200,000/μL. Our literature review reveals that this condition is refractory to steroid therapy. LDL-A can be an effective treatment in drug-resistant MN complicated by ITP.