Histological reappraisal of IgA nephropathy: the role of glomerular pattern of injury and mesangial complement deposition.

BACKGROUND: There is a clear need to refine the histological assessment in IgA Nephropathy (IgAN). We sought to investigate the clinical significance of the light microscopy (LM) pattern of glomerular injury and of the intensity of mesangial C3 staining in IgAN. METHODS: We conducted a retrospective, observational study that included all patients with biopsy-proven primary IgAN that had at least 12 months of follow-up. The LM pattern of glomerular injury was reevaluated based on a modified HAAS classification. Mesangial C3 deposition by immunofluorescence (IF) staining was scored semi-quantitatively. The study primary composite endpoint was defined as doubling of serum creatinine or ESRD (dialysis, renal transplant or eGFR < 15 ml/min). The secondary study endpoint was eGFR decline per year. RESULTS: This cohort included 214 patients with IgAN (mean age, 41.4 ± 12.6 years), with a mean eGFR and median 24-h proteinuria of 55.2 ± 31.5 ml/min/1.73m2 and 1.5 g/day (IQR:0.8-3.25), respectively. The most frequent LM pattern was the mesangioproliferative (37.4%), followed by the sclerotic (22.5%) and proliferative/necrotizing patterns (21.4%). Regarding the IF findings, mild-moderate and intense mesangial C3 staining was present in 30.6% and 61.1% of patients, respectively. Those with sclerosing and crescentic patterns had the worst renal survival (5-year renal survival of 48.8% and 42.9%) and the highest rate of eGFR change/year (-2.32 ml/min/y and - 2.16 ml/min/y, respectively) compared to those with other glomerular patterns of injury. In addition, those with intense C3 staining reached the composite endpoint more frequently compared to those without intense C3 staining (35.5% vs. 21.4%, p = 0.04). After multivariate adjustment, patients with crescentic and sclerosing patterns had a 3.6-fold and 2.1-fold higher risk for the composite endpoint compared to those with mesangioproliferative pattern, while an intense mesangial C3 deposition being also associated with a worse renal outcome (HR, 3.33; 95%CI, 1.21-9.2). CONCLUSIONS: We have shown that the LM pattern of glomerular injury and the intensity of mesangial C3 deposition might stratify more accurately the renal outcome in patients with IgAN.

The impact of SARS-CoV-2 infection on renal function in patients with biopsy-proven kidney diseases.

BACKGROUND: We sought to evaluate the long-term effects of COVID-19 on renal function in patients with biopsy-proven kidney diseases. METHODS: A total of 451 patients with biopsy-proven kidney disease and at least 12 months of follow-up subsequent to COVID-19 pandemic onset were included in the study. The primary study endpoint was a composite of a persistent decline of more than 30% in eGFR or ESRD. RESULTS: 23.1% of patients had COVID-19 during a follow-up period of 2.5 y (0.8-2.6), while 17.6% of patients reached the composite endpoint. Those with COVID-19 were more likely to reach the composite endpoint [26.7% vs. 14.8%; OR, 2.1 (95%CI, 1.23-3.58), p = 0.006). There was a significant eGFR change in the first year of follow-up between the two study groups [-2.24 (95%CI,-4.86; 0.37) vs. +2.31 (95%CI, 0.78; 3.85) ml/min, p = 0.004], with an adjusted mean difference of -4.68 ml/min (95%CI,-7.7; -1.59)(p = 0.03). The trend for worse renal outcomes remained consistent in patients with IgAN, MN and FSGS, but not in those with LN. After multivariate adjustment, the independent predictors of the composite endpoint were baseline eGFR (HR, 0.94; 95%CI, 0.92-0.95), COVID-19 (HR, 1.91; 1.16-3.12) and male gender (HR, 1.64; 95%CI, 1.01-2.66). In multivariate linear regression analysis, COVID-19 independently determined a reduction of eGFR at 12 months by 4.62 ml/min/1.73m2 (ß coefficient, -4.62; 95%CI, -7.74 to -1.5, p = 0.004). CONCLUSIONS: There is a significant impact of COVID-19 on long-term renal function in patients with biopsy-proven kidney diseases, leading to a greater decline of eGFR and a worse renal survival.

An open-label study evaluating the safety and efficacy of budesonide in patients with IgA nephropathy at high risk of progression.

We sought to evaluate the efficacy and safety of budesonide (Budenofalk) in the treatment of patients with IgA Nephropathy. We conducted a prospective, interventional, open-label, single-arm, non-randomized study that enrolled 32 patients with IgAN at high risk of progression (BUDIGAN study, ISRCTN47722295, date of registration 14/02/2020). Patients were treated with Budesonide at a dose of 9 mg/day for 12 months, subsequently tapered to 3 mg/day for another 12 months. The primary endpoints were change of eGFR and proteinuria at 12, 24 and 36 months. The study cohort had a mean eGFR and 24-h proteinuria of 59 ± 24 ml/min/1.73m2 and 1.89 ± 1.5 g/day, respectively. Treatment with budesonide determined a reduction in proteinuria at 12-, 24- and 36-months by -32.9% (95% CI - 53.6 to - 12.2), - 49.7% (95% CI - 70.1 to - 29.4) and - 68.1% (95% CI - 80.6 to - 55.7). Budesonide determined an eGFR preservation corresponding to a 12-, 24- and 36-months change of + 7.68% (95% CI - 4.7 to 20.1), + 7.42% (95% CI - 7.23 to 22.1) and + 4.74% (95%CI - 13.5 to 23), respectively. The overall eGFR change/year was + 0.83 ml/min/y (95% CI - 0.54 to 4.46). Budesonide was well-tolerated, and treatment emergent adverse events were mostly mild in severity and reversible. Budesonide was effective in the treatment of patients with IgAN at high-risk of progression in terms of reducing proteinuria and preserving renal function over 36 months of therapy.

Case Report: Hyponatremia Secondary to Desmopressin Administration Prior to Percutaneous Kidney Biopsy: A Case-Based Review.

Bleeding remains the most clinically relevant complication of kidney biopsy and several prophylactic approaches were proposed, including desmopressin administration. We present the case of a 60-year-old man with a history of liver transplantation, admitted for the evaluation of a renal dysfunction. As part of our department protocol, desmopressin 60 µg was administered orally, 2 h before the percutaneous kidney biopsy. The patient developed acute, severe, symptomatic hyponatremia (i.e., headache and recurrent vomiting), followed by a life-threatening upper gastrointestinal bleeding due to a Mallory-Weiss syndrome. Although it is often used as bleeding prophylaxis prior to kidney biopsy, data regarding the efficacy and safety of desmopressin in this setting are inconsistent. Accordingly, we performed a thorough literature review of the use of desmopressin as bleeding prophylaxis prior to kidney biopsy, focusing on the incidence of hyponatremia. The reported incidence of hyponatremia (<130 mmol/l) was 7-11%, probably because serum sodium was monitored in few studies. Nevertheless, hyponatremia was rarely symptomatic but, in some cases, like the one presented here, its complications could be severe. Pre-biopsy low serum sodium and estimated glomerular filtration rate as well as high spot urine sodium and non-restricted fluid intake were reported to be associated with hyponatremia incidence. However, the current evidence cannot clearly establish which patients benefit the most from desmopressin use with respect to bleeding complications. We propose that when desmopressin is used for bleeding prophylaxis prior to kidney biopsy, measurements of serum sodium levels, before and every 6 h after, should complement ultrasound and hemoglobin as part of the patient post-procedural monitoring. Also, water intake should be restricted in the day of biopsy. However, this proposed approach should be adequately evaluated in a clinical trial.