Influence of chronic kidney disease and its severity on the efficacy of semaglutide in type 2 diabetes patients: a multicenter real-world study.

Objectives: Semaglutide is a glucagon-like peptide 1 receptor agonist that improves glycemic control and achieves weight loss in type 2 diabetes (T2D) patients. Subcutaneous (s.c.) semaglutide at 1 mg once weekly (OW) is safe in T2D patients with chronic kidney disease (CKD). Whether or not CKD and its severity influence treatment response remains undetermined. Method: This is an observational, ambispective, multicenter, nationwide, real-world study designed to compare safety/efficacy of OW s.c. 1 mg semaglutide in T2D patients with or without CKD. The influence of CKD severity was also addressed. Patients were followed up for 12 months. Primary end-points were glycosylated hemoglobin (HbA1c), weight, and renal outcomes. Secondary end-points included insulin resistance, atherogenic and hepatic steatosis indexes, and changes in antihyperglycemic medications. Results: A total of 296 and 190 T2D patients without or with CKD, respectively, were recruited. Baseline CKD risk was moderate, high, or very high in 82, 53, and 45 patients, respectively. Treatment reduced HbA1c by 0.90%-1.20%. Relevant differences were seen neither between non-CKD and CKD patients nor among CKD subgroups. Notable weight losses were achieved in both non-CKD and CKD patients. The median reduction was higher in the former at 6 months (5.90 kg vs. 4.50 kg, P = 0.008) and at end of study (6.90 kg vs. 5.00 kg, P = 0.087). A trend toward slightly lower weight losses as CKD severity increased was observed. CKD markers improved across all CKD subgroups. Relevant differences were not observed for other variables, either between non-CKD and CKD patients, or among CKD subgroups. Safety concerns were not reported. Conclusion: The safety/efficacy of OW s.c. semaglutide to improve glycemic control and weight in T2D patients with CKD is not notably lower than that in T2D patients without renal failure. CKD severity barely influences treatment response. OW s.c. semaglutide can be useful to manage T2D patients with CKD in daily clinical practice.

Genetic testing in focal segmental glomerulosclerosis: in whom and when?

Background: Genetic causes are increasingly recognized in patients with focal segmental glomerulosclerosis (FSGS), but it remains unclear which patients should undergo genetic study. Our objective was to determine the frequency and distribution of genetic variants in steroid-resistant nephrotic syndrome FSGS (SRNS-FSGS) and in FSGS of undetermined cause (FSGS-UC). Methods: We performed targeted exome sequencing of 84 genes associated with glomerulopathy in patients with adult-onset SRNS-FSGS or FSGS-UC after ruling out secondary causes. Results: Seventy-six patients met the study criteria; 24 presented with SRNS-FSGS and 52 with FSGS-UC. We detected FSGS-related disease-causing variants in 27/76 patients (35.5%). There were no differences between genetic and non-genetic causes in age, proteinuria, glomerular filtration rate, serum albumin, body mass index, hypertension, diabetes or family history. Hematuria was more prevalent among patients with genetic causes. We found 19 pathogenic variants in COL4A3-5 genes in 16 (29.3%) patients. NPHS2 mutations were identified in 6 (16.2%) patients. The remaining cases had variants affecting INF2, OCRL, ACTN4 genes or APOL1 high-risk alleles. FSGS-related genetic variants were more common in SRNS-FSGS than in FSGS-UC (41.7% vs 32.7%). Four SRNS-FSGS patients presented with NPHS2 disease-causing variants. COL4A variants were the most prevalent finding in FSGS-UC patients, with 12 patients carrying disease-causing variants in these genes. Conclusions: FSGS-related variants were detected in a substantial number of patients with SRNS-FSGS or FSGS-UC, regardless of age of onset of disease or the patient's family history. In our experience, genetic testing should be performed in routine clinical practice for the diagnosis of this group of patients.

Donor antigen-specific regulatory T-cell function affects outcome in kidney transplant recipients.

Chronic transplant dysfunction, a major impediment to long-term allograft survival, is caused by several factors including an ongoing alloimmune response termed chronic rejection. To define some of these factors further, we selected 107 patients mismatched to their donors from 623 patients transplanted at a single center. Patients were categorized according to their immunosuppressive treatment and further divided into those with stable or chronic allograft dysfunction. Donor human lymphocyte antigen allopeptide-specific T-cell lines were then generated from stable patients and those with biopsy-proven chronic allograft nephropathy. Increased amounts of CD4+CD25+ regulatory T cells (Tregs) and Treg-associated gene expression profiles were found in cell lines derived from the patients with stable compared with those with chronic allograft dysfunction. Furthermore, a higher percentage of Tregs was found in patients with stable graft function on tacrolimus-based compared with cyclosporine-based immunosuppression protocols. Patients with stable graft function had a significantly higher expression of interleukin (IL)-4 and IL-10, whereas the cytokines IL-2, IL-17, and interferon-γ were significantly higher in patients with allograft dysfunction in vitro. Thus, enhancing the operational role of naturally occurring donor-specific Tregs in allograft recipients by adjusting the immunosuppression protocol may be advantageous particularly for patients with ongoing chronic rejection.

Regulatory allospecific T cell clones abrogate chronic allograft rejection.

True alloantigen-specific tolerance is the ultimate goal of solid organ transplantation, eliminating the need for long-term immunosuppression. Recent evidence suggests that Th1-derived cytokines are associated with rejection and Th2-derived cytokines with long-term allograft survival, but the roles of these subsets in rejection and tolerance are incompletely understood. Here, we analyzed the functional and regulatory capacities of T cell clones derived from tolerant and rejecting rats (Wistar rat donors, Lewis rat recipients). We generated and subcloned T cell lines from lymphocytes derived from either acutely rejecting grafts or from the grafts of CTLA4-Ig-treated tolerant rats. Pretransplantation adoptive transfer of T cell clones generated from rejected grafts (Th1 clones) accelerated acute rejection or promoted development of chronic rejection, whereas transfer of T cell clones generated from tolerized grafts (Th2 clones) protected rats from acute rejection and progressive organ dysfunction. When Th1 and Th2 clones were injected simultaneously, Th2 clones specifically regulated activation of Th1 clones. Rats that received injections of Th2 clones accepted long-term donor-specific skin grafts but acutely rejected third-party skin grafts. Tolerant rats treated with Th2 clones demonstrated an increased number of regulatory CD4+CD25+Foxp3+ cells and strong mononuclear cell staining for IL-10 but negligible IFN-gamma, IL-17, and IL-23 compared with untreated rats or those treated with Th1 clones. In summary, these results demonstrate the regulatory functions of Th2 cells in a clinically relevant allogeneic transplant model and provide new insight into the functional role of Th2 cells in preventing the process of chronic rejection.

Expression of adhesion molecules and RANTES in kidney transplant from nonheart-beating donors.

The main difference between cadaveric kidneys from donors with a heartbeat (HBD) and kidneys from nonheart-beating donors (NHBD) is related to warm ischemia/reperfusion time which constitutes an acute inflammatory process. On the contrary, brain death induces in HBD expression of pro-inflammatory adhesion molecules, making it important to evaluate this kind of molecules in both types of donors. Human renal biopsies from NHBD, HBD and normal kidneys (ischemia time = 0) were taken and frozen just before transplant. A semi-quantitative RT-PCR method was used to determine intracellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), lymphocyte function associated antigen (LFA-1), LFA-3, CD40, CD40 ligand (CD40L) and RANTES (regulated upon activation, normal T-cell expressed and secreted) gene expression. We have detected an elevated relative gene expression of ICAM-1, VCAM-1 and RANTES in NHBD biopsies compared with normal kidneys. In the case of RANTES, the gene expression from NHBD biopsies was higher than observed in HBD biopsies. The rest of genes were not augmented in any group. Preliminary data about early outcome of transplants indicates a correlation between pretransplant RANTES high gene expression levels and early post-transplant acute rejection. The gene expression of pro-inflammatory molecules like adhesion molecules and RANTES is augmented in kidneys from cadaveric NBD just before transplant. The expression is higher probably because of the prolonged warm ischemia period. A larger clinical study is necessary to clarify the effects of these variable expressions on the transplant outcome.

Pauci-immune extracapillary glomerulonephritis and atheromatous embolization.

Renal atheroembolic disease presents several multisystemic signs and symptoms that may resemble the clinical signs of vasculitis. A few cases of renal atheroembolism associated with antineutrophil cytoplasmic antibodies (ANCA) have been described. We report the first case, to our knowledge, of a patient with cholesterol microemboli who also developed extracapillary glomerulonephritis in the presence of perinuclear ANCA (p-ANCA) with anti-myeloperoxidase ANCA. The patient had long-term follow-up of renal function after treatment with prednisone and cyclophosphamide.