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.

Sodium citrate versus sodium bicarbonate for metabolic acidosis in patients with chronic kidney disease: A randomized controlled trial.

BACKGROUND: Metabolic acidosis (MA) is frequently associated with chronic kidney disease (CKD) progression. Our aim was to compare the effect of oral sodium citrate (SC) with that of oral sodium bicarbonate (SB) on renal function and serum bicarbonate correction, as well as to evaluate their safety profile in patients with MA of CKD. METHODS: We conducted a prospective, single-center, randomized 1:1, parallel, controlled, unblinded clinical trial of 124 patients with MA and CKD stages 3b and 4. The primary outcome was the mean change in estimated glomerular filtration rate (eGFR). The secondary outcomes were mean change in serum bicarbonate level, eGFR decrease by 30%, eGFR decrease by 50%, dialysis, death or prolonged hospitalization, and a combined endpoint. RESULTS: No significant difference was found between the groups in terms of mean eGFR change [adjusted mean difference = -0.99 mL/min/1.73 m2 (95% CI: -2.51 to 0.93, P = .20)]. We observed a mean serum bicarbonate change of 6.15 mmol/L [(95% CI: 5.55-6.74), P < .001] in the SC group and of 6.19 mmol/L [(95% CI: 5.54-6.83), P < .001] in the SB group, but no significant difference between the 2 groups [adjusted mean difference = 0.31 mmol/L (-0.22 to 0.85), P = .25]. Cox proportional hazard analysis showed similar risks regarding eGFR decrease by 30% (P = .77), eGFR decrease by 50% (P = .50), dialysis (P = .85), death or prolonged hospitalization (P = .29), and combined endpoint (P = .57). Study drug discontinuation due to adverse events was significantly more common in the SB group (17.7% vs 4.8%, P = .02). CONCLUSIONS: SC and SB have a similar effect on kidney function decline, both improve serum bicarbonate level, but SB is associated with higher rates of medication discontinuation due to adverse events.

ANCA-associated vasculitis in a HIV-infected patient:a case-based review.

BACKGROUND: The occurrence of autoantibodies in human immunodeficiency virus (HIV)-infected patients has been previously reported, with a prevalence ranging from 20 to 83%. There are also a few reports of clinically relevant autoantibody profiles in HIV-positive patients that lead to true systemic autoimmune disease; these possible life-threatening diseases have to be considered and treated accordingly. CASE PRESENTATION: Here, we present the case of a 29-year-old female patient with a history of well-controlled HIV infection in the last 6 years who was admitted to our department for the evaluation of acute kidney injury and nephrotic syndrome with active urinary sediment. A diagnosis of systemic antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) with renal and pulmonary involvement was established. The patient was treated with cyclophosphamide, rituximab and tapering glucocorticoids,and the diffuse alveolar hemorrhage resolved, but the evolution of kidney function was unfavorable, which led to the need to initiate hemodialysis. We highlight the importance of establishing the correct diagnosis, treating the disease accordingly and the possible clinical issues that can appear in a patient with HIV infection during immunosuppressant treatment as induction treatment. Additionally, we performed a thorough literature review of ANCA positivity in HIV-infected patients to properly understand the current evidence. CONCLUSIONS: Although it is not clear whether HIV infection and AAV are causally or coincidentally related, the possibility of this systemic autoimmune phenomenon should be acknowledged by physicians to establish the correct diagnosis and treat the disease accordingly by maintaining a balance between the risks and benefits of immunosuppression in this category of patients, with treatment decisions being made by the members of a multidisciplinary team in centers with experience in AAV.

Relapse of cryoglobulinemic vasculitis with new-onset severe renal involvement in two patients following mRNA COVID-19 vaccination: A case report.

RATIONALE: Since mass-scale severe acute respiratory syndrome coronavirus 2 vaccination, there have been case reports of several immune-mediated reactions, including new-onset and flares of glomerular disorders following immunization with mRNA coronavirus disease 2019 vaccines. Here, we report two cases, the first to our knowledge, of relapsing cryoglobulinemic vasculitis with new-onset severe renal involvement following mRNA coronavirus disease 2019 vaccination. PATIENT CONCERNS: The relapse of the cutaneous and the new onset of severe renal involvement of cryoglobulinemic vasculitis occurred three weeks after the second dose of the mRNA Moderna coronavirus disease 2019 vaccination and two days after the first dose of mRNA Pfizer coronavirus disease 2019 vaccination in the first and second patient, respectively. DIAGNOSIS: Kidney biopsies were performed. The first pacient's kidney biopsy showed a membranoproliferative pattern of glomerular injury with extensive mesangial and endocapillary hypercellularity, while severe endothelial swelling, loss of fenestrations and widening of subendothelial space were identified by electron-microscopy. The second patient's kidney biopsy was consistent with cryoglobulin associated membrano-proliferative pattern of glomerular injury. INTERVENTIONS: Our patients were managed with a combination of immunosuppressants consisting of corticosteroids, Cyclophosphamide and Rituximab with a favourable outcome at the end of the induction period. OUTCOMES: Clinical and immunological response was achieved in both patients after four months of follow-up. LESSONS: The temporal association of the relapse of the cryoglobulinemic vasculitis to mRNA coronavirus disease 2019 vaccination suggest that the vaccine might have been a trigger for the reactivation of the disease in our cases. This possible association should be acknowledged by physicians in order to provide optimal monitoring and treatment in case of reactivation of the disease post-immunization.

Immunosuppression as a Risk Factor for De Novo Angiotensin II Type Receptor Antibodies Development after Kidney Transplantation.

(1) Background: Angiotensin II type I receptor antibodies (AT1R-Ab) represent a topic of interest in kidney transplantation (KT). Data regarding the risk factors associated with de novo AT1R-Ab development are lacking. Our goal was to identify the incidence of de novo AT1R-Ab at 1 year after KT and to evaluate the risk factors associated with their formation. (2) Methods: We conducted a prospective cohort study on 56 adult patients, transplanted between 2018 and 2019. Recipient, donor, transplant, treatment, and complications data were assessed. A threshold of >10 U/mL was used for AT1R-Ab detection. (3) Results: De novo AT1R-Ab were observed in 12 out of 56 KT recipients (21.4%). The median value AT1R-Ab in the study cohort was 8.5 U/mL (inter quartile range: 6.8-10.4) and 15.6 U/mL (10.8-19.8) in the positive group. By multivariate logistic regression analysis, induction immunosuppression with anti-thymocyte globulin (OR = 7.20, 95% CI: 1.30-39.65, p = 0.02), maintenance immunosuppression with immediate-release tacrolimus (OR = 6.20, 95% CI: 1.16-41.51, p = 0.03), and mean tacrolimus trough level (OR = 2.36, 95% CI: 1.14-4.85, p = 0.01) were independent risk factors for de novo AT1R-Ab at 1 year after KT. (4) Conclusions: De novo AT1R-Ab development at 1 year after KT is significantly influenced by the type of induction and maintenance immunosuppression.

Hanta hemorrhagic fever with renal syndrome: A pathology in whose diagnosis kidney biopsy plays a major role (Review).

Hantavirus infection belongs to a group of zoonoses rare in the Balkan Peninsula, causing two major syndromes, depending on the viral serotype involved: Hemorrhagic fever with renal syndrome (HFRS) also known as endemic nephropathy and cardiopulmonary syndrome (CPS). Because there is no specific treatment or vaccine for this condition approved in the USA or Europe, the key to minimizing the risk of adverse progression to chronic kidney disease, secondary hypertension or even death is primarily the recognition and early diagnosis of this condition with prompt therapeutic intervention. The aim of this study was to review the literature data on the epidemiology, pathogenesis and management of this disease and to identify several aspects related to the difficulties encountered in diagnosing this pathology, taking into consideration that the disease is not endemic in this geographical area.

The early impact of preformed angiotensin II type 1 receptor antibodies on graft function in a low immunological risk cohort of kidney transplant recipients.

Intruduction and aim: Angiotensin II type 1 receptor antibodies (AT1R-Ab) are associated with graft rejection and poor graft outcomes in kidney transplantation (KT). We aimed to assess the frequency of preformed AT1R-Ab and their impact on graft function and survival at 1 year after KT in a low immunological risk cohort. METHODS: We performed a prospective, observational cohort study in 67 adult KT recipients, transplanted between 2018 and 2019. A cut-off value >10 U/ml was used for AT1R-Ab detection. RESULTS: The frequency of preformed AT1R-Ab was 10.4% and the median value of their level was 8.4 U/ml (IQR: 6.8-10.4). Donor-specific anti-human leukocyte antigen antibodies (HLA-DSA) were absent, no case of biopsy-proven rejection was reported and the incidence of graft failure was 7.5%. Estimated glomerular filtration rate (eGFR) was significantly reduced in the AT1R-Ab group [35 (29.8-55.2) vs 56.1 (41.3-66.5) ml/min, p = 0.02] at 1 year after KT. After multivariate linear regression analysis, preformed AT1R-Ab were found as an independent determinant of eGFR at 1 year after KT (ß: -15.395; 95% CI: -30.49 - -0.30; p = 0.04). By Cox multivariate regression analysis, preformed AT1R-Ab were not associated with graft failure (HR: 1.36; 95% CI:0.10-14.09; p = 0.80). CONCLUSION: Preformed AT1R-Ab are an independent determinant of graft function but do not impact graft survival at 12 months after transplantation in a prospective low immunological risk cohort of KT recipients.