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 (β 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.

Oral Furosemide and Hydrochlorothiazide/Amiloride versus Intravenous Furosemide for the Treatment of Resistant Nephrotic Syndrome

BACKGROUND

Data on diuretic treatment in nephrotic syndrome (NS) are scarce. Our goal was to assess the non-inferiority of the combined oral diuretics (furosemide/hydrochlorothiazide/amiloride) compared to intravenous (i.v.) furosemide in patients with NS and resistant edema.

METHODS

We conducted a prospective randomized trial on 22 patients with resistant nephrotic edema (RNE), defined as hypervolemia and a FENa < 0.2%. Based on a computer-generated 1:1 randomization, we assigned patients to receive either intravenous furosemide (40 mg bolus and then continuous administration of 5 mg/h) or oral furosemide (40 mg/day) and hydrochlorothiazide/amiloride (50/5 mg/day) for a period of 5 days. Clinical and laboratory measurements were performed daily. Hydration status was assessed by bioimpedance on day 1 and at the end of day 5 after treatment initiation. The primary endpoint was weight change from baseline to day 5. Secondary endpoints were hydration status change measured by bioimpedance and safety outcomes (low blood pressure, severe electrolyte disturbances, acute kidney injury and worsening hypervolemia).

RESULTS

Primary endpoint analysis showed that after 5 days of treatment, there was a significant difference in weight change from baseline between groups [adjusted mean difference: -3.33 kg (95% CI: -6.34 to -0.31), p = 0.03], with a higher mean weight change in the oral diuretic treatment group [-7.10 kg (95% CI: -18.30 to -4.30) vs. -4.55 kg (95%CI: -6.73 to -2.36)]. Secondary endpoint analysis showed that there was no significant difference between groups regarding hydration status change [adjusted mean difference: -0.05 L (95% CI: -2.6 to 2.6), p = 0.96], with a mean hydration status change in the oral diuretic treatment group of -4.71 L (95% CI: -6.87 to -2.54) and -3.91 L (95% CI: -5.69 to -2.13) in the i.v. diuretic treatment group. We observed a significant decrease in adjusted mean serum sodium of -2.15 mmol/L [(95% CI: -4.25 to -0.05), p = 0.04]), favored by the combined oral diuretic treatment [-2.70 mmol/L (95% CI: -4.89 to -0.50) vs. -0.10 mmol/L (95%CI: -1.30 to 1.10)]. No statistically significant difference was observed between the two groups in terms of adverse events.

CONCLUSIONS

A combination of oral diuretics based on furosemide, amiloride and hydrochlorothiazide is non-inferior to i.v. furosemide in weight control of patients with RNE and a similar safety profile.

Anti-phospholipase A2 receptor antibody screening in nephrotic syndrome may identify a distinct subset of patients with primary membranous nephropathy

PURPOSE

We sought to investigate the utility of anti-PLA2R antibody as a non-invasive screening method for the diagnosis of primary MN in patients with nephrotic syndrome (NS).

METHODS

All consecutive patients with NS admitted in our department, between 01.01.2015 and 31.12.2019 were screened for anti-PLA2R antibodies by an ELISA assay (EUROIMMUN, Lübeck, DE). A positive anti-PLA2R serology was defined as an ELISA value over 2 RU/ml. Subsequently, all patients underwent kidney biopsy to confirm the histological diagnosis.

RESULTS

Of the 203 patients with NS, we identified 67 patients with "high" titer of anti-PLA2R antibodies (> 20 RU/ml) and 47 patients with "intermediate" titer (2-20 RU/ml). In the entire cohort, the area under the curve (AUC) was 0.83 (95% CI 0.78-0.89; p < 0.001). With a cutoff of 20 RU/ml, the anti-PLA2R antibodies had a 64% sensitivity (95% CI 53-73%) and 94% specificity (95% CI 88-97%) to discriminate MN from other causes of NS. In addition, the PPV and NPV were 91% (95% CI 82-95%) and 75% (95% CI 69-79%). When analyzing the posttest effect, we identified a LR+ of 11.56 (95% CI 5.2-25.2) and LR- of 0.38 (95% CI 0.29-0.5). The overall accuracy of the test was 80.3% (95% CI 74-85%) and the diagnostic odds ratio was 30.42. When performing subgroup analysis, we identified that in younger patients, in those with preserved renal function or with negative workup for secondary causes, the diagnostic performance of anti-PLA2R antibodies was improved, the sensitivity increasing to 68-71%, the PPV to 93-95% and the LR+ to 12.23-15.4.

CONCLUSION

Serum anti-PLA2R antibody screening in patients with NS is a useful method for the diagnosis of primary MN. In younger patients (less than 60 years old) who have a preserved renal function and a negative workup for secondary causes of NS, a positive anti-PLA2R test highly predicts a diagnosis of primary MN.

Corticosteroids are the major contributors to the risk for serious infections in autoimmune disorders with severe renal involvement

INTRODUCTION

We sought to investigate the infection profile and associated risk factors in a compiled cohort of patients with autoimmune disorders with severe renal involvement treated with aggressive immunosuppressive (IS) regimens.

METHODS

A total of 162 patients with aggressive glomerulonephritis [101 with lupus nephritis (LN), 24 with cryoglobulinemic vasculitis (CryoVasc), and 37 with ANCA-associated vasculitis (AAV)] were retrospectively reviewed for any infection occurrence. Infection incidence, type, site, and grade (1-5) were recorded. Multivariate Cox proportional hazard regression analysis was performed to identify independent risk factors for infections.

RESULTS

A total of 179 infection episodes occurred during a follow-up of 468 patient-years. Eighty-two patients (50.6%) had at least one infection. The incidence rates of infections and severe infections were 38.2 and 14.3 events per 100 patient-years. Patients with AAV had more infections than those with CryoVasc and LN (100.6, 47.5, and 26.6 infections per 100-patient-years, respectively; p = 0.002). Most patients developed infections early during the initial induction therapy (62.1% in the first 6 months of follow-up). In multivariate Cox regression analysis, high-dose oral corticosteroids (≥ 0.5 mg/kg/day in the first month of induction therapy) was an independent predictor of any infection (HR 2.66; 95% CI, 1.5-4.73), severe infections (HR 2.45; 95% CI, 1.03-5.82), and pulmonary infections (HR 2.91; 95% CI, 1.05-8.01). Pulmonary involvement increased the risk for pulmonary infections (HR 3.67; 95% CI, 1.32-10.1) and severe infections (HR 2.45; 95% CI, 1.01-5.92).

CONCLUSION

Infections occur frequently with current IS regimens in aggressive glomerulonephritis. Pulmonary involvement and high-dose corticosteroid regimen were the most significant risk factors for infections. Key Points • Infections occur frequently with current immunosuppressive regimens in autoimmune aggressive glomerulonephritis. • High-dose corticosteroids are the major contributors to the risk for serious infections.