Bertelli Roberta, Bonanni Alice, Caridi Gianluca, Canepa Alberto, Ghiggeri G M
Laboratory of Molecular Nephrology, Genoa, Italy.
Nephrology, Dialysis, Transplantation Unit, Integrated Department of Pediatrics and Hemato-Oncology Sciences, Istituto Giannina Gaslini IRCCS, Genoa, Italy.
Front Med (Lausanne). 2018 Jun 11;5:170. doi: 10.3389/fmed.2018.00170. eCollection 2018.
Minimal Change Disease (MCD) is a clinical condition characterized by acute nephrotic syndrome, no evident renal lesions at histology and good response to steroids. However, frequent recurrence of the disease requires additional therapies associated with steroids. Such multi-drug dependence and frequent relapses may cause disease evolution to focal and segmental glomerulosclerosis (FSGS) over time. The differences between the two conditions are not well defined, since molecular mechanisms may be shared by the two diseases. In some cases, genetic analysis can make it possible to distinguish MCD from FSGS; however, there are cases of overlap. Several hypotheses on mechanisms underlying MCD and potential molecular triggers have been proposed. Most studies were conducted on animal models of proteinuria that partially mimic MCD and may be useful to study glomerulosclerosis evolution; however, they do not demonstrate a clear-cut separation between MCD and FSGS. Puromycin Aminonucleoside and Adriamycin nephrosis are models of glomerular oxidative damage, characterized by loss of glomerular basement membrane polyanions resembling MCD at the onset and, at more advanced stages, by glomerulosclerosis resembling FSGS. Also Buffalo/Mna rats present initial lesions of MCD, subsequently evolving to FSGS; this mechanism of renal damage is clearer since this rat strain inherits the unique characteristic of overexpressing Th2 cytokines. In Lipopolysaccharide nephropathy, an immunological condition of renal toxicity linked to B7-1(CD80), mice develop transient proteinuria that lasts a few days. Overall, animal models are useful and necessary considering that they reproduce the evolution from MCD to FSGS that is, in part, due to persistence of proteinuria. The role of T/Treg/Bcells on human MCD has been discussed. Many cytokines, immunomodulatory mechanisms, and several molecules have been defined as a specific cause of proteinuria. However, the hypothesis of a single cell subset or molecule as cause of MCD is not supported by research and an interactive process seems more logical. The implication or interactive role of oxidants, Th2 cytokines, Th17, Tregs, B7-1(CD80), CD40/CD40L, c-Mip, TNF, uPA/suPAR, Angiopoietin-like 4 still awaits a definitive confirmation. Whole genome sequencing studies could help to define specific genetic features that justify a definition of MCD as a "clinical-pathology-genetic entity."
微小病变性肾病（MCD）是一种临床病症，其特征为急性肾病综合征、组织学上无明显肾脏病变且对类固醇治疗反应良好。然而，疾病的频繁复发需要与类固醇联合的其他治疗方法。这种多药依赖和频繁复发可能随着时间的推移导致疾病进展为局灶节段性肾小球硬化（FSGS）。由于两种疾病可能共享分子机制，这两种病症之间的差异尚未明确界定。在某些情况下，基因分析可以区分MCD和FSGS；然而，也存在重叠的病例。关于MCD潜在机制和潜在分子触发因素已经提出了几种假说。大多数研究是在蛋白尿动物模型上进行的，这些模型部分模拟MCD，可能有助于研究肾小球硬化的演变；然而，它们并未明确区分MCD和FSGS。嘌呤霉素氨基核苷和阿霉素肾病是肾小球氧化损伤的模型，其特征是肾小球基底膜多阴离子的丧失，在疾病初期类似于MCD，在更晚期则类似于FSGS的肾小球硬化。同样，布法罗/Mna大鼠最初表现为MCD病变，随后发展为FSGS；这种肾损伤机制更为明确，因为该大鼠品系继承了过度表达Th2细胞因子的独特特征。在脂多糖肾病中，一种与B7-1（CD80）相关的肾毒性免疫病症，小鼠会出现持续数天的短暂蛋白尿。总体而言，考虑到动物模型再现了从MCD到FSGS的演变，部分原因是蛋白尿的持续存在，所以动物模型是有用且必要的。已经讨论了T/Treg/B细胞在人类MCD中的作用。许多细胞因子、免疫调节机制以及几种分子已被确定为蛋白尿的特定原因。然而，单一细胞亚群或分子作为MCD病因的假说并未得到研究支持，一个相互作用的过程似乎更符合逻辑。氧化剂、Th2细胞因子、Th17、Tregs、B7-1（CD80）、CD40/CD40L、c-Mip、TNF、uPA/suPAR、血管生成素样4的影响或相互作用作用仍有待最终确认。全基因组测序研究有助于确定特定的遗传特征，从而证明将MCD定义为“临床 - 病理 - 遗传实体”是合理的。
