Pediatric Kidney Biopsies in Oman: A Retrospective Study.

Objectives: To determine the spectrum of kidney diseases in Omani children < 13 years of age and to evaluate the complications following kidney biopsy. Methods: This study retrospectively investigated the hospital data of children who underwent kidney biopsies from January 2014 to June 2019 at Royal Hospital, Muscat, Oman. Results: The subjects comprised of 78 children with a median age of 8.0 years (range = 0-13 years). Histopathology showed minimal change disease in 15 (19.2%) children, lupus nephritis in 13 (16.7%), and focal segmental glomerulosclerosis in 13 (16.7%). The most common post-biopsy complications were pain that required analgesia (38; 49.4%) followed by gross hematuria (10; 13.0%). No patient required blood transfusion or surgical intervention. Conclusions: Minimal change disease was the most common histopathological finding in this cohort of Omani children. The records did not mention any major complications following the renal biopsy procedure.

Genetic analysis and outcomes of Omani children with steroid-resistant nephrotic syndrome.

BACKGROUND: Nephrotic syndrome (NS) is one of the most common kidney disorders seen by pediatric nephrologists and is defined by the presence of heavy proteinuria (>3.5 g/24 h), hypoalbuminemia (<3.5 g/dL), edema, and hyperlipidemia. Most children with NS are steroid-responsive and have a good prognosis following treatment with prednisolone. However, 10%-20% of them have steroid-resistant nephrotic syndrome (SRNS) and fail to respond to treatment. A significant proportion of these children progress to kidney failure. METHODS: This retrospective study aimed to determine the underlying genetic causes of SRNS among Omani children below 13 years old, over a 15-year period and included 77 children from 50 different families. We used targeted Sanger sequencing combined with next-generation sequencing approaches to perform molecular diagnostics. RESULTS: We found a high rate of underlying genetic causes of SRNS in 61 (79.2%) children with pathogenic variants in the associated genes. Most of these genetically solved SRNS patients were born to consanguineous parents and variants were in the homozygous state. Pathogenic variants in NPHS2 were the most common cause of SRNS in our study seen in 37 (48.05%) cases. Pathogenic variants in NPHS1 were also seen in 16 cases, especially in infants with congenital nephrotic syndrome (CNS). Other genetic causes identified included pathogenic variants in LAMB2, PLCE1, MYO1E, and NUP93. CONCLUSION: NPHS2 and NPHS1 genetic variants were the most common inherited causes of SRNS in Omani children. However, patients with variants in several other SRNS causative genes were also identified. We recommend screening for all genes responsible for SRNS in all children who present with this phenotype, which will assist in clinical management decisions and genetic counseling for the affected families.

Pediatric Renal Transplantation in Oman: A Single-center Experience.

OBJECTIVES: This study sought to report 22 years experience in pediatric kidney transplantation in Oman. METHODS: Electronic charts of all Omani children below 13 years of age who received a kidney transplant from January 1994 to December 2015 were reviewed. Data collected included patient demographics, etiology of end-stage kidney disease, modality and duration of dialysis, donor type, complication of kidney transplantation (including surgical complications, infections, graft rejection) graft and patient survival, and duration of follow-up. RESULTS: During the study period transplantation from 27 living related donors (LRDs), 42 living unrelated donors (LURDs), also referred to as commercial transplant, and one deceased donor were performed. The median age at transplantation was nine years for both groups. The most common primary diagnosis was congenital anomalies of the kidney and urinary tract in 32.8% of patients followed by familial nephrotic syndrome in 20.0% and polycystic kidney disease in 18.5%. Almost half the patients were on hemodialysis before transplantation, 35.7% were on peritoneal dialysis, and 14.2% received preemptive renal transplantation. Children who received LURD kidneys had high surgical complications (42.8%) compared to the LRDs group (17.8%). Five patients from LURDs group had early graft nephrectomy and four patients developed non-graft function or delayed graft function. In addition, patients in the LURDs group had a higher incidence of hypertension and acute rejection. Graft and patient survival were both better in the LRDs than the LURDs group. CONCLUSIONS: Although our pediatric kidney transplant program is a young program it has had successful patient outcomes comparable to international programs. Our study provides evidence that in addition to legal and ethical issues with commercial transplant, it also carries significantly higher morbidity and reduced graft and patient survival.