Department of Medicine, Division of Nephrology, Ohio State University Wexner Medical Center, Columbus, OH, USA.
Department of Pathology, University of Washington Medical Center, Seattle WA, USA.
Nephrol Dial Transplant. 2018 Jul 1;33(7):1168-1175. doi: 10.1093/ndt/gfx238.
It has been suggested that the prognosis of immunoglobulin (IgA) nephropathy (IgAN) is adversely affected if there is codeposition of IgG in the glomeruli or if immune deposits are present in the glomerular capillary walls. We sought to understand how these variables affect clinical outcome.
A total of 80 IgAN biopsies were retrospectively divided into groups: (i) IgA without IgG deposition versus IgA + IgG and (ii) immune deposits restricted to the mesangium versus mesangium and peripheral capillary walls (PCWs). The association of these groups with the composite primary outcome of renal replacement therapy, renal transplant, death or doubling of serum creatinine (SCr) concentration was determined. The change in estimated glomerular filtration rate (eGFR) was also assessed. Covariates examined were age, sex, race, SCr and proteinuria level at biopsy and at follow-up, duration of follow-up, treatment, Oxford score and presence of crescents.
IgG codeposition showed a trend toward endocapillary hypercellularity (P = 0.082); there were no other baseline differences between the IgA (n = 55) and IgA + IgG (n = 25) groups. At a median follow-up time of 29 months, the combined primary outcome was reached in 24 patients, 16 with IgA and 8 with IgA + IgG (P = 0.82). Patients with immune deposits in the PCWs (n = 21) presented with higher baseline proteinuria than those with deposits limited to the mesangium (n = 59; P = 0.025), were more likely to have crescents/segmental glomerular necrosis on biopsy (P = 0.047) and were more likely to reach the combined primary outcome (P = 0.026). Biopsies with crescents/segmental glomerular necrosis were associated with endocapillary hypercellularity (P < 0.001).
In this multicenter IgAN cohort, IgG co-deposition and the location of glomerular immune deposits in the PCWs were both associated with greater histologic activity on renal biopsy, but only the location of glomerular immune deposits in the PCWs was associated with a significantly increased risk for end-stage renal disease, transplant, death and/or doubling of SCr.
有人提出，如果免疫球蛋白（Ig）在肾小球中共同沉积或免疫沉积物存在于肾小球毛细血管壁中，IgA 肾病（IgAN）的预后会受到不利影响。我们试图了解这些变量如何影响临床结果。
总共回顾性地将 80 例 IgAN 活检分为两组：（i）IgA 无 IgG 沉积与 IgA+IgG 和（ii）免疫沉积物局限于系膜与系膜和外周毛细血管壁（PCW）。确定这些组与包括肾脏替代治疗、肾移植、死亡或血清肌酐（SCr）浓度加倍在内的复合主要终点之间的关联。还评估了估算肾小球滤过率（eGFR）的变化。检查的协变量是年龄、性别、种族、活检时和随访时的 SCr 和蛋白尿水平、随访时间、治疗、牛津评分和新月体的存在。
IgG 共同沉积显示出向毛细血管内细胞增生的趋势（P=0.082）；在 IgA（n=55）和 IgA+IgG（n=25）两组之间没有其他基线差异。在中位数为 29 个月的随访期间，24 例患者达到了复合主要终点，其中 16 例为 IgA，8 例为 IgA+IgG（P=0.82）。PCW 中存在免疫沉积物的患者（n=21）的基线蛋白尿水平高于仅在系膜中存在沉积物的患者（n=59；P=0.025），在活检时更有可能存在新月体/节段性肾小球坏死（P=0.047），并且更有可能达到复合主要终点（P=0.026）。有新月体/节段性肾小球坏死的活检与毛细血管内细胞增生相关（P<0.001）。
在这个多中心 IgAN 队列中，IgG 共同沉积和肾小球免疫沉积物在 PCW 中的位置均与肾活检时更大的组织学活动相关，但只有肾小球免疫沉积物在 PCW 中的位置与终末期肾病、移植、死亡和/或 SCr 加倍的风险显著增加相关。
