Appearance of new CDC-reactive antibodies in patients waiting for kidney transplantation

BackgroundPatients awaiting kidney transplantation are regularly screened for HLA-antibodies, but there is scarce data about the optimal interval.MethodsResults from Complement-dependent cytotoxicity testing (CDC) for waitlisted patients were reviewed for increases in panel reactive antibodies (PRA) by at least 10%-points. Clinical records were screened for historic immunizing events and possible trigger factors preceding the PRA-increase. Additionally, non-pretransplanted men tested negative for HLA antibodies by solid-phase assays (SPA) out of their first two samples on the waiting list (“non-immunized men”) were evaluated for detection of HLA antibodies by SPA during their further stay on the waiting list.Results15,360 samples from 1928 patients tested by CDC were analyzed for changes in PRA. PRA-increases occurred most frequently in patients waitlisted recently for retransplantation (annual incidence 6%). Removal of previous transplants, severe infections and/or reduced immunosuppression triggered 65% of PRA-increases during the first year after waitlisting. Transfusions accounted for 55% of PRA-increases in later years. Leucocyte-reduced red blood cell units not only boosted historic antibodies, but even induced primary immunization. In the second part of the study, 6780 samples tested by SPA from 703 non-immunized men were evaluated for development of HLA-antibodies. Only 9 men (1.3%) turned HLA antibody-positive (annual incidence 0.4%).ConclusionA uniform screening interval does not fit all: Frequencies should be highest in patients newly waitlisted for re-transplant and lowest in non-immunized men. Transfused patients should be monitored closely for development of HLA-antibodies even if leukoreduced products are used.     

变性高效液相色谱检测 PKD2基因突变

目的　利用变性高效液相色谱分析技术 ( denaturing high- performance liquidchromatography,DHPL C) ,检测 2型常染色体显性遗传性多囊肾病致病基因 ( polycystic kidney diseasegene 2 ,PKD2 )突变。方法　收集临床确诊的汉族常染色体显性遗传性多囊肾病 ( autosomal dominantpolycystic kidney disease,ADPKD) 94个家系 ,提取外周血白细胞 DNA,用聚合酶链反应 ( polymerasechain reaction,PCR)扩增目的基因的全编码区 ,DHPL C对 PCR产物进行突变筛选 ,出现异常峰型的DNA片段进行核苷酸序列测定 ,明确突变位点和类型。结果　以 5 0名健康志愿者为正常对照 ,从 94例患者家系中成功检测出 8种突变 ,包括 2种无义突变、3种移码突变、3种错义突变。无义突变分别位于第 5和13外显子 ( 12 4 9C→ T,2 4 0 7C→ T) ,编码氨基酸分别在 4 17和 80 3位形成终止密码子。移码突变分别位于第2、12和 13外显子 ( 6 36 - 6 37ins T,2 348- 2 35 1del AGAA,2 4 0 1del A)。错义突变分别位于第 1、4和 5外显子 ( 5 6 8G→ A,96 4 C→T,116 8G→A) ,其编码氨基酸发生改变 ( 190 Ala→ Thr,32 2 Arg→Trp,390 Gly→ Ser)。结论　所检测出的 8种突变 ,为 ADPKD患者的基因诊断、产前诊断和囊肿前诊断积累了资料     

基质金属蛋白酶1/组织金属蛋白酶抑制因子1在常染色体显性遗传性多囊肾组织中的表达

目的:探讨基质金属蛋白酶1(MMP1)/组织金属蛋白酶抑制因子(TIMP1)在正常肾脏、常染色体显性遗传性多囊肾病(ADPKD)肾脏以及肾移植平均(2.5±1.2)年后切除的ADPKD肾组织中的表达差异.方法:用基因表达谱芯片筛选正常肾脏、ADPKD肾脏及肾脏移植后ADPKD肾脏的差异表达基因;以RT-PCR法验证其中差异表达的MMP1/TIMP1.结果:基因芯片筛选发现在正常肾组织与ADPKD肾组织中存在463条差异表达基因,肾移植后ADPKD肾组织对比ADPKD肾组织存在130条差异表达基因.筛选结果表明ADPKD以及肾移植后ADPKD肾脏MMP1/TIMP1表达较正常肾组织明显上调(P＜0.05),而前两者间无显著差异.RT-PCR法证实MMP1/TIMP1在ADPKD肾脏以及肾移植后ADPKD肾组织中的表达均明显上调,明显高于正常肾脏组织(P＜0.05),而前两者间无显著差异.结论:ADPKD的病理改变可能与MMPs/TIMPs基因表达失衡有关,MMPs抑制剂可能会对其有一定的治疗作用.