LIMS1 risk genotype and T cell-mediated rejection in kidney transplant recipients.

BACKGROUND: This study aims to examine the association of LIM zinc finger domain containing 1 (LIMS1) genotype with allograft rejection in an independent kidney transplant cohort. METHODS: We genotyped 841 kidney transplant recipients for the LIMS1 rs893403 variant by Sanger sequencing followed by polymerase chain reaction confirmation of the deletion. Recipients who were homozygous for the LIMS1 rs893403 genotype GG were compared with the AA/AG genotypes. The primary outcome was T cell-mediated or antibody-mediated rejection (TCMR or ABMR, respectively) and secondary outcome was allograft loss. RESULTS: After a median follow-up of 11.4 years, the rate of TCMR was higher in recipients with the GG genotype (n = 200) compared with the AA/AG genotypes (n = 641) [25 (12.5%) versus 35 (5.5%); P = 0.001] while ABMR did not differ by genotype [18 (9.0%) versus 62 (9.7%)]. Recipients with the GG genotype had 2.4 times higher risk of TCMR than those who did not have this genotype [adjusted hazard ratio2.43 (95% confidence interval 1.44-4.12); P = 0.001]. A total of 189 (22.5%) recipients lost their allografts during follow-up. Kaplan-Meier estimates of 5-year (94.3% versus 94.4%; P = 0.99) and 10-year graft survival rates (86.9% versus 83.4%; P = 0.31) did not differ significantly in the GG versus AA/AG groups. CONCLUSIONS: Our study demonstrates that recipient LIMS1 risk genotype is associated with an increased risk of TCMR after kidney transplantation, confirming the role of the LIMS1 locus in allograft rejection. These findings may have clinical implications for the prediction and clinical management of kidney transplant rejection by pretransplant genetic testing of recipients and donors for LIMS1 risk genotype.

EFI region 8 Balkan external proficiency testing for HLA typing: Results of 15 years.

Istanbul Medical Faculty, Department of Medical Biology, as the first EFI-accredited HLA laboratory in Turkey since 1999 has been organizing both national and international quality control tests for HLA typing under the banner of the "Balkan external proficiency testing (BEPT)" encompassing countries from EFI regions 8. The first round of BEPT in 2004 was organized for low-resolution HLA-A,-B typing by molecular methods and 12 centres participated in the exercise. In 2005, low-resolution HLA-DR typing was added, and in 2007, low-resolution HLA-C and DQ typing were added to the exercise and 28 centres participated. In 2015, high-resolution (four digits or higher typing) HLA-A,-B,-C,-DR and -DQ typing added to the exercise and 40 centres participated. In the last 2 years, 2017 and 2018, the number of participating centres increased to 48 and 52, respectively. When the distribution of low-resolution typing methods applied in the exercises were investigated, it was found that 82% of the centres in the first round of BEPT in 2004 used PCR-SSP, whereas in the last round in 2018, 26% of the centres preferred SSP, while the rest used SSO (50%) or SSP and SSO (24%) methods. Methods for high-resolution typing were SBT (41%), NGS (18%), SSO (18%), SSP (6%), SBT + NGS (6%) and SBT + SSP (11%). In 15th trial for BEPT, nomenclature mistake rate was 12%, and erroneous result rate was 6% for HLA samples. The most common mistakes in the exercises were nomenclature mistakes. The EFI Standards Version 7.0 is stated "HLA type can be reported using a hyphen if homozygosity is not proven by family studies." In order to provide standard results among HLA laboratories and since accurate HLA typing leads to significant increase of graft and patient survival, quality control exercises should be performed in all HLA-based tests periodically.

Immunosuppressive Treatment in C3 Glomerulopathy: Is it Really Effective?

BACKGROUND: C3 glomerulopathy (C3GP) is a recently identified and described disease that has a high risk of progressing into end-stage renal disease. We aimed to evaluate the effects of various immunosuppressive regimens on C3GP progression because there are conflicting data on the treatment modalities. METHODS: In this retrospective study of 66 patients with C3GP, 27 patients received mycophenolate mofetil (MMF)-based treatment, 23 received non-MMF-based treatment (prednisolone or cyclophosphamide), and 16 received conservative care. The study groups were compared with each other with specific focus on primary outcomes defined as (1) kidney failure and (2) estimated glomerular filtration rate (eGFR) decline ≥50% from the baseline value. RESULTS: Overall, 17 (25.8%) patients reached the primary outcome after a median period of 28 months. The number of patients who reached the primary outcome were similar among the study groups (MMF-based: 8/27 [29.6%], non-MMF-based: 4/23 [17.4%], and conservative care: 5/16 [31.3%], p = 0.520). In the Cox regression analysis, age (HR 0.912, p = 0.006), eGFR (HR 0.945, p = 0.001), and proteinuria levels (HR 1.418, p = 0.015) at the time of biopsy, percentage of crescentic (HR 1.035, p = 0.001) and sclerotic glomeruli (HR 1.041, p = 0.006), severity of interstitial fibrosis (HR 1.981, p = 0.048), as well as no remission of proteinuria (HR 2.418, p = 0.002) predicted the primary outcome. CONCLUSION: Although patients receiving immunosuppressive treatments had higher proteinuria and lower serum albumin at baseline, there were no differences between these patients and those receiving conservative care alone in proteinuria remission or in the decline of renal function. Younger age, higher proteinuria, lower eGFR, and the presence of crescentic and sclerotic glomeruli, severity of interstitial fibrosis, and no remission of proteinuria predicted the progression of kidney disease.

Re-evaluation of glomerulitis using occlusion criteria based on the Banff 2013 revision: a retrospective study.

The presence of occlusion/near-occlusion of glomerular capillaries was recently added to the existing definition of glomerulitis (g). We retrospectively re-evaluated 135 renal allograft biopsies regarding g to ensure no antibody-damaged grafts were missed. Previous and revised g scores (pg and rg, respectively) were compared for clinicopathologic correlations. The g score did not change in 100 (74.1%) biopsies. Thirty-five (25.9%) biopsies were changed to a lower score. Sensitivity and specificity of pg and rg for the presence of donor-specific antibodies (DSA) were 76% vs. 58% and 70% vs. 79%, respectively. Pg score indicated graft loss with 65% sensitivity and 63% specificity, whereas rg showed 46% sensitivity and 71% specificity. Area under the curve (AUC) values in ROC analysis for DSA and graft loss were as follows: pg, 0.773; rg, 0.693; and pg, 0.635; rg, 0.577, respectively. A comparison of the two AUC values revealed a significant difference between pg and rg only for DSA (P = 0.0076). Pg and post-transplant time of biopsy independently predicted graft loss, whereas rg did not. In conclusion, revised g scores showed lesser sensitivity but higher specificity for DSA and graft loss. Recent definition of g missed antibody-mediated rejection in few cases, and it was not an independent predictor for graft loss.

The novel HLA-B*39:199 allele identified in a candidate bone marrow donor.

HLA-B*39:199 differs from HLA-B*39:10:01 by a G → A substitution in exon 5 in codon 282.

COSMC expression as a predictor of remission in IgA nephropathy.

PURPOSE: The impact of core 1,3-galactosyltransferase-specific molecular chaperon (COSMC) gene expression and methylation profile on clinical progression of IgA nephropathy (IgAN) is unclear. The aim of this study was to determine the clinical significance and the relation of the COSMC gene expression and methylation pattern with the progression of IgAN. METHODS: Thirty-nine biopsy-confirmed IgAN patients, 11 healthy relatives and 20 healthy controls were recruited. The COSMC mRNA levels and methylation profile of COSMC gene promoter were measured using the quantitative real-time PCR. The galactose-deficient IgA1 (Gd-IgA1) levels were measured using ELISA in serum and cell culture supernatant. The effect of IL-4 and AZA on COSMC expression and methylation and the correlation of COSMC gene expression and methylation levels with baseline kidney function tests, histology and long-term outcomes were examined. RESULTS: The mean COSMC mRNA level was significantly lower, and serum Gd-IgA1 level was higher in IgAN patients compared with the control groups (p < 0.001, and p = < 0.001, respectively). The COSMC mRNA levels were correlated with intensity of hematuria (r = - 0.41, p = 0.009), serum creatinine level (r = - 0.37, p = 0.002) and eGFR (r = 0.36, p = 0.002). The COSMC methylation levels were correlated with age (r = 0.25, p = 0.04) and baseline eGFR (r = - 0.326, p = 0.006). Twenty IgAN patients (51.3%) reached to complete (5, 12.8%) or partial remission (15, 38.5%) after a median of 34.5 months (IQR, 13.75-71). In multivariable Cox regression analysis, COSMC mRNA expression (adjusted HR (aHR) 1.871, 95% CI 1.287-2.722, p = 0.001) and Oxford T score (aHR 0.355, 95% CI 0.146-0.859, p = 0.022) predicted the remission. CONCLUSION: COSMC mRNA level is a novel biomarker candidate to predict the remission in IgAN patients.

Standard immunosuppressive treatment reduces regulatory B cells in children with autoimmune liver disease.

Introduction: Autoimmune hepatitis (AIH) is a chronic liver disease caused by a perturbed immune system. The scarcity of short- and long-term immune monitoring of AIH hampered us to comprehend the interaction between immunosuppressive medication and immune homeostasis. Methods and patients: We recruited children with AIH at the time of diagnosis and at the 1st, 3rd, 6th, 12th, 18th, and 24th months of immunosuppression (IS). We also enrolled children with AIH being on IS for >2 years. Children with drug-induced liver injury (DILI), and those receiving tacrolimus after liver transplantation (LT), were enrolled as disease/IS control subjects. Healthy children (HC) were also recruited. Peripheral blood mononuclear cells (PBMCs) were isolated from all participants. Healthy liver tissue from adult donors and from livers without inflammation were obtained from children with hepatoblastoma. By using flow cytometry, we performed multi-parametric immune profiling of PBMCs and intrahepatic lymphocytes. Additionally, after IS with prednisolone, tacrolimus, rapamycin, or 6-mercaptopurine, we carried out an in vitro cytokine stimulation assay. Finally, a Lifecodes SSO typing kit was used to type HLA-DRB1 and Luminex was used to analyze the results. Results: Untreated AIH patients had lower total CD8 T-cell frequencies than HC, but these cells were more naïve. While the percentage of naïve regulatory T cells (Tregs) (CD4+FOXP3lowCD45RA+) and regulatory B cells (Bregs, CD20+CD24+CD38+) was similar, AIH patients had fewer activated Tregs (CD4+FOXP3highCD45RA - ) compared to HC. Mucosal-associated-invariant-T-cells (MAIT) were also lower in these patients. Following the initiation of IS, the immune profiles demonstrated fluctuations. Bregs frequency decreased substantially at 1 month and did not recover anymore. Additionally, the frequency of intrahepatic Bregs in treated AIH patients was lower, compared to control livers, DILI, and LT patients. Following in vitro IS drugs incubation, only the frequency of IL-10-producing total B-cells increased with tacrolimus and 6MP. Lastly, 70% of AIH patients possessed HLA-DR11, whereas HLA-DR03/DR07/DR13 was present in only some patients. Conclusion: HLA-DR11 was prominent in our AIH cohort. Activated Tregs and MAIT cell frequencies were lower before IS. Importantly, we discovered a previously unrecognized and long-lasting Bregs scarcity in AIH patients after IS. Tacrolimus and 6MP increased IL-10+ B-cells in vitro.

Oxidative stress and macrophage infiltration in IgA nephropathy.

BACKGROUND: The aim of this study was to evaluate the interactions among serum levels of galactose-deficient IgA1 (Gd-IgA1), oxidative stress and macrophage infiltration and their clinical correlates in patients with IgA Nephropathy (IgAN). METHODS: A total of 47 patients with biopsy-proven primary IgAN, aged between 16 and 79 years, with a follow-up period ≥ 1 year or who showed progression to end stage kidney disease (ESKD) regardless the duration of follow-up were included. Study endpoint was the progression to ESKD. Serum Gd-IgA1 and advanced oxidation protein product (AOPP) levels were measured using ELISA assays. Kidney biopsies were evaluated according to the Oxford MEST-C scoring, with C4d and CD68 staining. RESULTS: Seventeen patients (36%) experienced ESKD during a median follow-up time of 6 years (IQR 3.7-7.5). Serum AOPP levels were correlated with the intensity of glomerular C3 deposition (r = 0.325, p = 0.026), glomerular (r = 0.423, p = 0.003) and interstitial CD68 + cell count (r = 0.298, p = 0.042) and Gd-IgA1 levels (r = 0.289, p = 0.049). Serum Gd-IgA1 levels were correlated with the intensity of C3 deposition (r = 0.447, p = 0.002). eGFR at biopsy (adjusted HR (aHR) 0.979 p = 0.011), and E score (aHR, 8.305, p = 0.001) were associated with progression to ESKD in multivariate analysis. 5-year ESKD-free survival rate was significantly lower in patients with higher E score compared to patients with E score 0 [p = 0.021]. CONCLUSIONS: An increased number of macrophages in the glomerular and tubulointerstitial area may play a role in oxidative stress and complement system activation. Endocapillary hypercellularity is a predictive factor for poor prognosis in IgAN.

Recombination frequencies of human leukocyte antigen loci in hematological malignancies among Turkish population.

INTRODUCTION: Allogeneic hematopoietic stem cell transplantation (HSCT) is a treatment option with growing performance for leukaemia, aplastic anaemia and genetic disorders. The frequency of MHC (Major Histocompatibility Complex) gene locus recombination is increased at loci close to the telomeres and in the female gender. The aim of the present study is to document the recombination events by pedigree diagrams with the primary goal to determine the frequency of recombination in a different ethnic population from mostly reported studies. METHODS: Altogether 9545 allogeneic HSCT recipients and their family-based potential donors (n:36231) were included in this retrospective study. RESULTS: Recombinations were determined in 118 (F/M:50/68) out of 9545 families enrolled on the study. These were present in 40 of the patients and 78 of healthy donors. The frequency of recombinations was 0.42% and 0.22%, in patients and donors, respectively. Of the 118 recombinations, 60 were detected in A locus (13 inpatients), 14 in B locus (3 inpatients) and 42 in DR locus (22 inpatients). In our study, due to recombinations in HLA (Human Leukocyte Antigen)-A,-B,-DR loci, we found that some patient-donor pairs became 6/5 matched instead of 6/6 (n:45), eliminating the allogeneic HSCT possibility for the patients from the full-matched siblings. CONCLUSION: To our knowledge, this is the first study reporting the recombination frequencies in HLA loci among Turkish population and thus, providing informative data to the clinicians regarding the cross-over possibilities in Turkish patients with haematological malignancies.

PROGRESS STUDY: Progression of chronic kidney disease in children and heat shock proteins.

Various molecular and cellular processes are involved in renal fibrosis, such as oxidative stress, inflammation, endothelial cell injury, and apoptosis. Heat shock proteins (HSPs) are implicated in the progression of chronic kidney disease (CKD). Our aim was to evaluate changes in urine and serum HSP levels over time and their relationships with the clinical parameters of CKD in children. In total, 117 children with CKD and 56 healthy children were examined. The CKD group was followed up prospectively for 24 months. Serum and urine HSP27, HSP40, HSP47, HSP60, HSP70, HSP72, and HSP90 levels and serum anti-HSP60 and anti-HSP70 levels were measured by ELISA at baseline, 12 months, and 24 months. The urine levels of all HSPs and the serum levels of HSP40, HSP47, HSP60, HSP70, anti-HSP60, and anti-HSP70 were higher at baseline in the CKD group than in the control group. Over the months, serum HSP47 and HSP60 levels steadily decreased, whereas HSP90 and anti-HSP60 levels steadily increased. Urine HSP levels were elevated in children with CKD; however, with the exception of HSP90, they decreased over time. In conclusion, our study demonstrates that CKD progression is a complicated process that involves HSPs, but they do not predict CKD progression. The protective role of HSPs against CKD may weaken over time, and HSP90 may have a detrimental effect on the disease course.

Can Direct-Acting Antiviral Treatment Change the Immunologic Risk Profile in Patients Infected with Hepatitis C Virus Who Are on the Cadaveric Waiting List?

BACKGROUND: In patients with hepatitis C virus (HCV) infection, the activation of the immune system by the virus or viral proteins leads to the production of numerous autoantibodies and clinical manifestations. The objectives of this study were to investigate the relationship between HCV and anti-HLA antibodies, as well as the effect of viremia on the antibody response and of direct-acting antivirals (DAAs) on anti-HLA antibody persistence in patients on the waiting list for a cadaveric kidney transplant. METHODS: A total of 395 patients from the cadaveric renal transplant waiting list were included in the study. The patients were grouped according to the presence of HCV infection, and patients with HCV positivity were further divided into a spontaneous clearance group and a persistent group. Anti-HLA antibodies were examined before and after treatment of the patients in the persistent group. The One Lambda Luminex method (Thermo Fisher Scientific, Waltham, MA, United States) was used to assess both HLA class I and II alleles and the anti-HLA antibody profile. RESULTS: Anti-HLA class I and II antibodies were detected in 48.2% and 55.1%, respectively, of the patients infected with HCV and in 21.8% and 20.4%, respectively, of the patients who were not infected. The level of anti-HLA A3, A11, B72, B52, Cw6, Cw16, DR3, and DQ4 antibodies was significantly higher in the patients infected with HCV. There was no statistically significant difference in class I and II antibody titration between the HCV-infected spontaneous clearance group and the persistent group (class I mean fluorescence intensity [MFI] ± SD: 13,583 ± 6224, 13,450 ± 9540, P = .808; Class II MFI ± SD: 13,000 ± 8673, 8440 ± 8302, P = .317, respectively). There was no significant difference in the class I and class II anti-HLA antibody profile and titration in the persistent group after treatment with DAAs (P > .05). CONCLUSIONS: The results of this study demonstrated that hepatitis C DAA treatment did not change the anti-HLA antibody profile and titration.

The genetic architecture of membranous nephropathy and its potential to improve non-invasive diagnosis.

Membranous Nephropathy (MN) is a rare autoimmune cause of kidney failure. Here we report a genome-wide association study (GWAS) for primary MN in 3,782 cases and 9,038 controls of East Asian and European ancestries. We discover two previously unreported loci, NFKB1 (rs230540, OR = 1.25, P = 3.4 × 10-12) and IRF4 (rs9405192, OR = 1.29, P = 1.4 × 10-14), fine-map the PLA2R1 locus (rs17831251, OR = 2.25, P = 4.7 × 10-103) and report ancestry-specific effects of three classical HLA alleles: DRB1*1501 in East Asians (OR = 3.81, P = 2.0 × 10-49), DQA1*0501 in Europeans (OR = 2.88, P = 5.7 × 10-93), and DRB1*0301 in both ethnicities (OR = 3.50, P = 9.2 × 10-23 and OR = 3.39, P = 5.2 × 10-82, respectively). GWAS loci explain 32% of disease risk in East Asians and 25% in Europeans, and correctly re-classify 20-37% of the cases in validation cohorts that are antibody-negative by the serum anti-PLA2R ELISA diagnostic test. Our findings highlight an unusual genetic architecture of MN, with four loci and their interactions accounting for nearly one-third of the disease risk.

Infectious Complications of Induction Therapies in Kidney Transplantation.

BACKGROUND Cytomegalovirus (CMV) and BK virus (BKV) are post-transplant opportunistic viral infections that affect patient and graft survival. This study was designed to evaluate the risk of BKV nephropathy and CMV disease in kidney transplant recipients who received induction therapy with ATG or basiliximab. MATERIAL AND METHODS We retrospectively analyzed information on 257 adult patients who underwent kidney transplantation between January 2007 and 2017. Patients were categorized into 3 groups according to the induction therapies. The primary endpoint was the onset of CMV disease or biopsy-confirmed BKV nephropathy. The secondary endpoints were biopsy-proven rejection episodes, graft loss, loss to follow-up, and death. RESULTS We followed 257 patients for a median of 55.5 months. The incidence of CMV disease was significantly higher in the only ATG group compared to the group without induction treatment (p<0.001). There was no significant difference in the incidence of BKV nephropathy among groups (p>0.05). The dosage of ATG (OR, 10.685; 95% CI, 1.343 5 to 85.009; P=0.025) was independent risk factor for death. CONCLUSIONS This study demonstrated that a higher dosage of ATG in high-risk patients is associated with an increased risk of CMV disease and patient death, also, reducing the dosage may be a rational strategy for increasing graft and patient's survival.

Evaluation of Glutathione Peroxidase and KCNJ11 Gene Polymorphisms in Patients with New Onset Diabetes Mellitus After Renal Transplantation.

Introduction Genetic mutations such as C599T polymorphism in glutathione peroxidase [GPX1] gene and polymorphisms in potassium channel (KCNJ11) genes have recently been proposed in the etiopathogenesis of new onset diabetes mellitus after renal transplantation (NODAT). We aimed to examine the association of GPX1 and KCNJ11 polymorphisms in NODAT. Materials and Methods This is a monocenter case-control study with a total of 118 renal transplant recipients who were divided into 2 groups; NODAT and normal glucose tolerance. Relation of GPX1 and KCNJ11 polymorphisms were investigated between these groups. PCR-RFLP method was used for genotyping of polymorphisms in the GPX1 (rs1050450) and KCNJ11 (rs1805127) genes. Two alleles were visualized for each gene (C/T for GPX1 and A/G for KCNJ11). Results NODAT was correlated with age at transplantation (p<0.001, r=0.380), post-transplant systolic blood pressure (BP) (p=0.02, r=0.211), post-transplant non-HDL cholesterol levels (p=0.01, r=0.803), degree of weight change at the end of the first year (p=0.01, r=0.471), presence of pre-transplant hypertension (HT) (p=0.02, r=0.201), family history of diabetes (p=0.01, r=0.29) and dyslipidemia (p=0.012, r=0.362). GPX1 polymorphism of TT (mutant) allele was significantly more frequent in patients with NODAT (p<0.001, r=0.396) independent from other diabetogenic risk factors. KCNJ11 polymorphisms were similar in both groups and did not show any significant association with NODAT (p=0.10). Conclusions In addition to several diabetogenic risk factors, C599T polymorphisms in GPX1 gene might also contribute to the development of NODAT. Further studies on larger patient series are necessary in order to reach definitive suggestions.