Abstract Background and Aims Biological sex has been associated to a more rapid rate of chronic kidney disease progression (ie, speed of kidney function loss) in male than female [1]. Testosterone can increase oxidative stress, activate the renin angiotensin system, and aggravate renal fibrosis, whereas estrogens inhibit these pathological processes in the diseased kidney [2]. Several factors such as lower disease awareness and surveillance rates as well as disparities in health-care access result in late initiation or lack of kidney replacement therapy among females [3-5]. The impact of sex in the clinical presentation and outcomes of patients with anti-neutrophil cytoplasmic antibodies (ANCA) associated vasculitis (AAV) with glomerulonephritis (AAV-GN) has not been studied, particularly in patients with severe kidney involvement at presentation (eGFR<15 mL/min/1.73 m2). Method A retrospective cohort study on MPO- or PR3-ANCA positive patients with AAV (MPA or GPA) and eGFR<15 ml/min/1.73 m2 or ESKD at presentation. Clinical presentation and outcomes (renal recovery, dialysis at presentation, and ESKD) were analyzed according with sex. Results We analyzed 166 patients with biopsy proven active AAV-GN and eGFR <15 mL/min/1.73 m2 at the time of diagnosis (Fig. 1): 78 (47%) were females and 88 (53%) were males. Arterial hypertension was more frequently present in males (85.2% vs. 70.5%, p = 0.022). Median serum creatinine (SCr) was higher in males when compared with females (5.2 [IQR 4.2-7.4] vs. 3.6 [IQR 2.8-5.1] mg/dL, p < 0.001) but there were no differences in eGFR at presentation. When analyzing only the 71 (24 females and 47 males) patients that started dialysis within 4 weeks, infections at 12 months were more common in females (75.0% vs. 36.2%, p = 0.017). The rate of dialysis initiation or progression to ESKD was not different between males (15, 62.5%) versus females (29, 61.7%) being on dialysis at 12 months. By multivariable logistic regression, factors related with dialysis initiation within 4 weeks in our cohort were SCr (OR1.478, [95% CI 1.231-1.776], p < 0.001), alveolar hemorrhage (OR 2.726, [95% CI 1.099-6.763], p = 0.031) and PR3-ANCA (OR3.155, [95% CI 1.485-6.702], p = 0.003) adjusted to sex). Patients who remained on dialysis at 12 months more often had higher SCr at diagnosis (IRR 1.098 [95% CI, 1.026–1.175], p = 0.007), severe chronicity changes on kidney biopsies (IRR 2.469 [95% CI,1.205–5.061], p = 0.014), higher chronicity score (IRR 1.178 [95%CI, 1.062-1.308], p = 0.002) and lower hemoglobin (IRR 0.824 [95%CI, 0.683-0.994], p = 0.043). Minimal chronicity changes were protective for the achievement of this endpoint (IRR 0.228 [95% CI, 0.070-0.741], p = 0.014). Multivariable Cox regression showed that patients with higher SCr at diagnosis and moderate/severe chronicity changes on biopsy were at higher risk to evolve to ESKD at 12 months compared to patients with lower chronicity grades, even when adjusted to sex. Conclusion In our cohort, male patients presented with higher SCr, and dialysis was started within 4 weeks more frequently. However, this did not result in different outcomes in terms of kidney recovery, overall dialysis rates, and progression to ESKD in patients with AAV-GN and eGFR<15 mL/min/1.73 m2 between groups.
Mycophenolate Mofetil (MMF) and Corticosteroids in Crescentic IgA Nephropathy (IgAN)
Abstract Background and Aims A significant number of patients with anti-neutrophil cytoplasmic antibodies (ANCA) associated vasculitis (AAV) with glomerulonephritis (AAV-GN) still progress to end-stage kidney disease (ESKD, eGFR<15mL/min/1.73m2) despite advances in remission-induction treatment. Method A retrospective cohort study on MPO- or PR3-ANCA positive patients with AAV (MPA or GPA) and ESKD at presentation. Renal recovery, dialysis discontinuation and maintenance in ESKD after standard remission-induction, with or without the use of PLEX were compared. Results We analyzed 166 patients with biopsy proven active kidney involvement and eGFR <15mL/min/1.73m2 at the time of AAV-GN diagnosis. Patients received glucocorticoids with CYC (n = 84) or with RTX (n = 72) for remission-induction, and 49 also received PLEX. The predictors for renal recovery were erythrocyte sedimentation rate, SCr at diagnosis and minimal or mild chronicity changes. We analyzed 71 patients who started dialysis with or without PLEX within 4 weeks from AAV-GN diagnosis. The predictors for dialysis discontinuation were minimal chronicity changes in kidney biopsy at the time of diagnosis (OR 6.138, [95%CI 1.389-27.118],p = 0.017) and focal glomerular involvement (OR 5.017,[95%CI 1.287-19.567],p = 0.020). Predictors for maintenance in ESKD at 12 months included higher serum creatinine (SCr) at the time of diagnosis (IRR 1.086, [95%CI 1.005-1.173],p = 0.037), moderate (IRR 3.797,[95%CI 1.090-13.225],p = 0.036), or severe chronicity changes in kidney biopsy (IRR 5.883,[95%CI 1.542–22.439],p = 0.009). Conclusion In our cohort, kidney recovery, dialysis discontinuation, and maintenance of ESKD in patients with AAV-GN and eGFR<15mL/min/1.73m2 depended on SCr and histologic findings on kidney biopsies at the time of diagnosis and was not affected by the addition of PLEX.
Shorter versus longer corticosteroid duration and recurrent immune checkpoint inhibitor-associated AKI
Background Corticosteroids are the mainstay of treatment for immune checkpoint inhibitor-associated acute kidney injury (ICPi-AKI), but the optimal duration of therapy has not been established. Prolonged use of corticosteroids can cause numerous adverse effects and may decrease progression-free survival among patients treated with ICPis. We sought to determine whether a shorter duration of corticosteroids was equally efficacious and safe as compared with a longer duration. Methods We used data from an international multicenter cohort study of patients diagnosed with ICPi-AKI from 29 centers across nine countries. We examined whether a shorter duration of corticosteroids (28 days or less) was associated with a higher rate of recurrent ICPi-AKI or death within 30 days following completion of corticosteroid treatment as compared with a longer duration (29–84 days). Results Of 165 patients treated with corticosteroids, 56 (34%) received a shorter duration of treatment and 109 (66%) received a longer duration. Patients in the shorter versus longer duration groups were similar with respect to baseline and ICPi-AKI characteristics. Five of 56 patients (8.9%) in the shorter duration group and 12 of 109 (11%) in the longer duration group developed recurrent ICPi-AKI or died (p=0.90). Nadir serum creatinine in the first 14, 28, and 90 days following completion of corticosteroid treatment was similar between groups (p=0.40, p=0.56, and p=0.89, respectively). Conclusion A shorter duration of corticosteroids (28 days or less) may be safe for patients with ICPi-AKI. However, the findings may be susceptible to unmeasured confounding and further research from randomized clinical trials is needed.
Kidney Histopathology in ANCA-Associated Vasculitides Treated with Plasma Exchange
Background and objectives Kidney biopsy is the current gold standard to diagnose membranous nephropathy. Approximately 70%–80% of patients with primary membranous nephropathy have circulating anti-phospholipase A2 receptor antibodies. We previously demonstrated that in proteinuric patients with preserved eGFR and absence of associated conditions ( e.g., autoimmunity, malignancy, infection, drugs, and paraproteinemia), a positive anti-phospholipase A2 receptor antibody test by ELISA and immunofluorescence assay confirms the diagnosis of membranous nephropathy noninvasively. These data have not been externally validated. Design, setting, participants, & measurements The clinical and pathologic characteristics of patients with a positive anti-phospholipase A2 receptor antibody test at the Mayo Clinic, the University Hospital Vall D’Hebron (Barcelona), and the Columbia University Medical Center (New York) were retrospectively reviewed. Biopsy findings and presence or absence of a potential associated condition were assessed. Results From a total of 276 patients with positive anti-phospholipase A2 receptor serology, previously reported patients ( n =33), kidney transplant recipients ( n =9), pediatric patients ( n =2), and patients without kidney biopsy ( n =69) were excluded. Among the 163 remaining patients, associated conditions were identified in 47 patients, and 15 patients had diabetes mellitus. All 101 patients of the final cohort had a primary diagnosis of membranous nephropathy on kidney biopsy. In the 79 patients with eGFR≥60 ml/min per 1.73 m 2 , none of the biopsy findings altered diagnosis or management. Among the 22 patients with decreased eGFR, additional findings included superimposed acute interstitial nephritis ( n =1). Conclusions In patients with preserved eGFR and absence of associated conditions or diabetes, a positive anti-phospholipase A2 receptor test by either ELISA >20 RU/ml or a positive immunofluorescence assay confirms the diagnosis of membranous nephropathy, precluding the requirement for a kidney biopsy.
Acute kidney injury in patients treated with immune checkpoint inhibitors
Background Immune checkpoint inhibitor-associated acute kidney injury (ICPi-AKI) has emerged as an important toxicity among patients with cancer. Methods We collected data on 429 patients with ICPi-AKI and 429 control patients who received ICPis contemporaneously but who did not develop ICPi-AKI from 30 sites in 10 countries. Multivariable logistic regression was used to identify predictors of ICPi-AKI and its recovery. A multivariable Cox model was used to estimate the effect of ICPi rechallenge versus no rechallenge on survival following ICPi-AKI. Results ICPi-AKI occurred at a median of 16 weeks (IQR 8–32) following ICPi initiation. Lower baseline estimated glomerular filtration rate, proton pump inhibitor (PPI) use, and extrarenal immune-related adverse events (irAEs) were each associated with a higher risk of ICPi-AKI. Acute tubulointerstitial nephritis was the most common lesion on kidney biopsy (125/151 biopsied patients [82.7%]). Renal recovery occurred in 276 patients (64.3%) at a median of 7 weeks (IQR 3–10) following ICPi-AKI. Treatment with corticosteroids within 14 days following ICPi-AKI diagnosis was associated with higher odds of renal recovery (adjusted OR 2.64; 95% CI 1.58 to 4.41). Among patients treated with corticosteroids, early initiation of corticosteroids (within 3 days of ICPi-AKI) was associated with a higher odds of renal recovery compared with later initiation (more than 3 days following ICPi-AKI) (adjusted OR 2.09; 95% CI 1.16 to 3.79). Of 121 patients rechallenged, 20 (16.5%) developed recurrent ICPi-AKI. There was no difference in survival among patients rechallenged versus those not rechallenged following ICPi-AKI. Conclusions Patients who developed ICPi-AKI were more likely to have impaired renal function at baseline, use a PPI, and have extrarenal irAEs. Two-thirds of patients had renal recovery following ICPi-AKI. Treatment with corticosteroids was associated with improved renal recovery.