Predicting graft survival in paediatric kidney transplant recipients using machine learning.

BACKGROUND: Identification of factors that affect graft survival in kidney transplantation can increase graft survival and reduce mortality. Artificial intelligence modelling enables impartial evaluation of clinician bias. This study aimed to examine factors that affect the survival of grafts in paediatric kidney transplantation through the use of machine learning. METHODS: A retrospective review was conducted on records of paediatric patients who underwent kidney transplantation between 1994 and 2021 and had post-transplant follow-up > 12 months. The nearest neighbour method was used to impute missing fields from a total of 48 variables in the dataset. Models including Naive Bayes, logistic regression, support vector machine (SVM), multi-layer perceptron, and XGBoost were trained to predict graft survival. The study used 80% of the patients for training and the remaining 20% for testing. Modelling success was evaluated based on accuracy and F1 score metrics. RESULTS: The study analysed 465 kidney transplant recipients. Of these, 56.7% were male. The mean age at transplantation was 12.08 ± 5.01 years. Of the kidney transplants, 73.1% (n = 339) were from living donors, 34.5% (n = 160) were pre-emptive transplants, and 2.2% (n = 10) were second-time transplants. The machine learning model identified several features associated with graft survival, including antibody-mediated rejection (+ 0.7), acute cellular rejection (+ 0.66), eGFR at 3 years (+ 0.43), eGFR at 5 years (+ 0.34), pre-transplant peritoneal dialysis (+ 0.2), and cadaveric donor (+ 0.2). The successes of the logistic regression and SVM models were similar. The F1 score was 91.9%, and accuracy was 96.5%. CONCLUSION: Machine learning can be used to identify factors that affect graft survival in kidney transplant recipients. By expanding similar studies, risk maps can be created prior to transplantation.

Therapeutic apheresis: is it safe in children with kidney disease?

BACKGROUND: Therapeutic apheresis (TA) is already used to treat various diseases in the field of nephrology. The aim of this study was to evaluate the frequency and types of complications that occur during TA in children with kidney disease. METHODS: Records of children (≤ 18 years) who underwent TA between 2007 and 2022 were retrospectively reviewed. Children with missing data and those with a diagnosis of nonnephrological disease were excluded. RESULTS: A total of 1214 TA sessions, including 1147 therapeutic plasma exchange (TPE) sessions and 67 immunoadsorption (IA) sessions, were performed on the 108 patients enrolled in the study. Forty-seven percent of the patients were male, and the mean age was 12.22 ± 4.47 years. Posttransplant antibody-mediated rejection (64.8%) and hemolytic uremic syndrome (14.8%) were the most common diagnoses indicating TA. Overall, 17 different complications occurred in 58 sessions (4.8%), and 53 sessions (4.6%) were not completed because of these complications. The distribution of complications among the patients was as follows: 41.4% had technical complications, 25.9% had allergic complications, and 32.7% had others. The most common technical complication was insufficient flow (37.5%). The incidence of complications was greater in patients aged 3-6 years than in patients in the other age groups (p = 0.031). The primary disease, type of vascular access, and rate of fresh frozen plasma/albumin use were similar between patients with and without complications (p values of 0.359 and 0.125 and 0.118, respectively). CONCLUSIONS: Our study showed that complications occurred in only 4.8% of TA sessions. The most common complication was technical problems.

Low C3 in a 4-month-old baby: is it a problem?

A 4-month-old male baby was admitted because his father and uncles had chronic kidney disease. His father was diagnosed with membranoproliferative glomerulonephritis at the age of 5, underwent a kidney transplant at the age of 22, and lost the graft due to recurrence of the disease. In contrast, the young uncle was diagnosed with C3 glomerulopathy and mycophenolate mofetil and eculizumab were initiated early. It was remarkable that our patient had normal kidney function and urine analyses but low serum C3 level (0.56 g/L; N, 0.9-1.8 g/L). In the disease-associated clinical exome analysis, a heterozygous change in the CFH gene was found. The same mutation was found homozygous in the uncle. In genetically inherited diseases, findings may occur sequentially; early screening of at-risk individuals contributes to kidney survival.

Complement gene mutations in children with C3 glomerulopathy: do they affect the response to mycophenolate mofetil?

BACKGROUND: C3 glomerulopathy (C3G) is a complement-mediated disease. Although genetic studies are not required for diagnosis, they are valuable for treatment planning and prognosis prediction. The aim of this study is to investigate the clinical phenotypes, kidney survival, and response to mycophenolate mofetil (MMF) treatment in pediatric C3G patients with and without mutations in complement-related genes. METHODS: Sixty pediatric C3G patients were included, divided into two groups based on complement-related gene mutations. Demographic and clinical-pathological findings, treatment modalities, and outcome data were compared, and Kaplan-Meier analysis was performed for kidney survival. RESULTS: Out of the 60 patients, 17 had mutations. The most common mutation was in the CFH gene (47%). The mean age at diagnosis was higher in the group with mutation (12.9 ± 3.6 vs. 11.2 ± 4.1 years, p = 0.039). While the patients without mutation most frequently presented with nephritic syndrome (44.2%), the mutation group was most likely to have asymptomatic urinary abnormalities (47.1%, p = 0.043). Serum parameters and histopathological characteristics were similar, but hypoalbuminemia was more common in patients without mutation. During 45-month follow-up,10 patients progressed to chronic kidney disease stage 5 (CKD5), with 4 having genetic mutation. The time to develop CKD5 was longer in the mutation group but not significant. MMF treatment had no effect on progression in either group. CONCLUSIONS: This study is the largest pediatric C3G study examining the relationship between genotype and phenotype. We showed that the mutation group often presented with asymptomatic urinary abnormalities, was diagnosed relatively late but was not different from the without mutation group in terms of MMF treatment response and kidney survival.

Treatment of BK Polyomavirus-Associated Nephropathy in Paediatric Kidney Transplant Recipients: Leflunomide Versus Cidofovir.

OBJECTIVES: BK polyomavirus-associated nephropathy is a clinicopathological entity that negatively affects graft function in kidney transplant recipients. We compared the efficacy of leflunomide and cidofovir to treat BK polyomavirus-associated nephropathy in pediatric kidney transplant recipients. MATERIALS AND METHODS: Medical records of pediatric recipients with BK viremia for the period 2004 through 2019 were reviewed retrospectively, and patients diagnosed with BK polyomavirusassociated nephro-pathy were included in the study. A serum BK virus level above 104 copies/mL was accepted as BK viremia. We defined BK polyomavirusassociated nephropathy as detection of BK virus SV40 antigen on immunochemistry staining of renal graft tissue accompanied by signs of tubulointerstitial nephritis or elevated serum creatinine in addition to BK viremia. RESULTS: Of 304 kidney transplant recipients, 53 had persistent BK viremia; 36 of these patients (61.1% male) were included in the study with the diagnosis of BK polyomavirus-associated nephropathy. Twelve patients (33.3%) received cidofovir, and 14 (38.8%) received leflunomide. Results were similar between the cidofovir and leflunomide groups for serum creatinine level at last follow-up (0.91 ± 0.29 vs 0.94 ± 0.37 mg/dL, respectively; P = .843) and graft failure rate (8.3% vs 14.2%, respectively; P = .632). Graft failure was observed in 8.3% of patients with BK polyomavirus-associated nephropathy. CONCLUSIONS: Leflunomide and cidofovir showed similar efficacy for treatment of BK polyomavirus-associated nephropathy.

High Respiratory Tract Infection Rate in Patients With Familial Mediterranean Fever.

Background Familial Mediterranean fever (FMF) is a systemic autoinflammatory disease genetically transmitted with the autosomal recessive trait. Although the pathogenesis is not certain, it is known that there is a deficiency in the regulation of the natural immune system. In this study, we aimed to search whether patients with FMF are predisposed to respiratory tract infections and whether mannose-binding lectin (MBL), as a natural immune system member, contributes to it. Methods Fifty FMF patients and 20 control groups were enrolled in the study. First, the frequencies of upper respiratory tract infection (URTI) within the previous year of both patient and control groups were evaluated retrospectively. Then, both groups were followed up for URTI for one year after starting the study. The patient's immunoglobulin A (IgA), IgM, IgG, C-reactive protein (CRP), hemogram parameters, and mannose-binding lectin were evaluated. Results The median frequency of annual URTI with a retrospective evaluation of patients was higher than that of the control group. Also, the median frequency of URTI with the prospective evaluation of patients with FMF was higher than the control group. The rate of patients with low serum IgG levels was higher in the patient group than in the control group. However, serum IgG levels of FMF patients with frequent URTI were not different from those without. The median MBL levels of both groups were similar (1312 vs. 1534 ng/ml for the patient and control group, respectively). The rate of patients having low serum MBL levels was also similar between the groups. Conclusions In the present study, we found that patients with FMF had more URTI than healthy controls. However, the underlying cause is not fully explained. There is a need for further studies with a higher number of patients evaluating URTI in patients with FMF.

Hirudinea (Annelida) Fauna of Some Wetlands in Bingöl Province

Objective: Leeches are important and reliable indicators of water quality and biodiversity in the ecosystem, so the presence of specific leech species is often closely related to basic water conditions and the presence of certain animals. This study was carried out in 2017 and 2018 in order to determine the Hirudinea fauna of some wetlands in Bingöl province. The investigation was conducted on a total of 13 stations. Methods: The water parameters of the stations were measured and recorded in situ. The collected specimens were brought alive to the Zoology Laboratory of Bingöl University Biology Department and kept alive under room temperature conditions. The diagnosis of leech samples was made through the living samples, and they were identified at the level of family, genus, and species. Results: During the study, seven species, belonging to six genera and in four families were recorded. These are; Hirudo verbana Carena, 1820, Glossiphonia complanata (L. 1758), Theromyzon tessulatum (O. F. Müller, 1774), Placopdella costata (Fr. Müller, 1846), Erpobdella octoculata (L., 1758), Erpobdella testacea (Savigny, 1820), Piscicola geometra (L., 1761). Conclusion: The locations where the study was carried out are new records for the detected leech species.

Graft Survival in Patients With Lower Urinary Tract Dysfunction.

OBJECTIVES: We aimed to the determine urinary tract infection and graft survival rates in pediatric renal transplant recipients with lower urinary tract dysfunction with particular focus on neurogenic bladder, posterior urethral valve, and vesicoureteral reflux nephropathy. MATERIALS AND METHODS: Patients were grouped according to primary diseases as those with and without lower urinary tract dysfunction. Urinary tract infections during year 1 posttransplant were investigated. Estimated glomerular filtration rate was calculated using Schwartz formula. RESULTS: Our study investigated 133 kidney transplant recipients. Lower urinary tract dysfunction was found in 58 patients (43.6%): 25 with posterior urethral valve, 24 with vesicoureteral reflux nephropathy, and 9 with neurogenic bladder. Rates of posttransplant urinary tract infection were higher in patients with lower urinary tract dysfunction than in those without during both the first 6 months posttransplant (24.6% vs 10.8%; P = .037) and between posttransplant months 6 and 12 (24.6% vs 8.2%; P = .01). Patients with neurogenic bladder had the highest rate of urinary tract infections, and their estimated glomerular filtrations rates were lower compared with patients with posterior urethral valve and vesicoureteral reflux nephropathy at month 6 and years 1, 2, and 5 posttransplant (P < .001). The 5-year graft survival rates of patients without lower urinary tract dysfunction and those with vesicoureteral reflux nephropathy were similar (51.3% vs 51.6%; P = .891). CONCLUSIONS: Graft survival rates of patients with posterior urethral valve and vesicoureteral reflux nephropathy were similar to those shown in patients without lower urinary system dysfunction; however, patients with neurogenic bladder had worse graft survival and urinary tract infection rates.