Chronic Tubulointerstitial Nephropathies (CTIN) in Children in the Paediatric Nephrology Department of Dakar: About 64 Cases between January 2015 and December 2022 Download PDF

Journal Name : SunText Review of Renal Sciences

DOI : 10.51737/renal.2024.020

Article Type : Research Article

Authors : Keita Y1,2, Faye M1,2, Dione S2, Ndongo AA1,2, Faye AA2, Sow A1,3, Boiro D1,3, Faye M1,2, Bacary BA1,2, Seye MD3, Takam BL3, Seck N4, Abou BA1,5, Indou Deme LY1,6, Thiongane A1,6, Fatou LY1,7, Lemrabott AT1,2, Gueye M1,3 and Sylla A1,2

Keywords : Polyuria-polydipsia; Nephronophthisis; Nephrocalcinosis; Tubulopathies; Chronic kidney disease

Abstract

Objective: To describe the diagnostic, therapeutic and evolutionary aspects of the CTIN cases treated in our department.

Patients and Method: We conducted a descriptive and analytical retrospective study of CTIN cases treated in the only paediatric nephrology department in Senegal between January 2015 and December 2022. The data collected were analysed with SPSS version 21 software.

Results: After data collection, 64 children were included during the study period, corresponding to a hospital prevalence of 9% (64/709) of the chronic kidney disease (CKD) monitored in our department. The average age of the children at the onset of the disease was 5.5 ± 5.3 years. The gender ratio (M/F) was 2.4 (45/19). The reasons for consultation were lumbar pain 28.1% (18/64), hypertension 17.2% (11/64), fever 15.6% (10/64), polyuropolydipsia 12.5% (8/64), proteinuria 12.5% (n=8), abacterial leukocyturia 6.2% (4/64) and hematuria 3% (2/64). Ultrasound examination revealed nephrocalcinosis in 43.9% (28/64) of cases. A renal biopsy was performed in 6.2% (4/64) of patients, confirming typical CTIN lesions. Crystalluria testing identified revealed uric acid in one case and a cystine calculus in another. Genetic testing was performed in 4.6% (3/64) of the children with 01 claudin-16 mutation, and 02 cases of familial mutation of the CTNS gene. Hereditary tubulopathies accounted for 53.1% (34/64) of the causes of CTINs, followed by reflux nephropathy 18.8% (12/64). The hospital mortality rate was 6.2% (4/64). Death was related to the development of CKD to dialysis stage V (p=0,001).

Conclusion: In our study, CTINs accounted for less than one tenth of the causes of CKD in children. Limited access to genetics and specific blood and urine tests was the major limitation in this study. Therefore, there is a need to provide diagnostic tools for CTIN in Dakar.


Introduction

exclusively affects the renal interstitium and takes longer than three months to develop [1-3]. Regardless of the cause, the majority of renal damage leads to the development of interstitial fibrosis and tubular atrophy, the presence of which indicates the inevitable progression to loss of renal function [1]. The phenotypic manifestations of CTINs are often diverse and are described as less specific [4]. Diagnostic certainty is based on renal biopsy [5]. However, in most studies, histological confirmation of CTIN cases is not always effective and the diagnosis relies on a number of presumptive arguments. In renal pathology, tubulopathies are less common than glomerular diseases [6]. Little is known about the prevalence of CTINs in children in sub-Saharan Africa, so our research hypothesis was that CTINs are common in children in Dakar and that there are several different aetiologies. The present study was conducted in this context with the aim of investigating the epidemiological, clinical, and paraclinical profile as well as the diagnosis of CTINs in children in the only paediatric nephrology department of Dakar.


Patients and Methods

The study was conducted in Senegal’s only paediatric nephrology department at Aristide Le Dantec University Hospital. Paediatric nephrology activities in this department included outpatient consultation, hospitalisation, renal biopsy and dialysis. In most cases, the children to be treated were referred by the pediatric facilities in Dakar and other regions of the country. Biological and radiological tests were available in Senegal, with the exception of genetics, some specific dosages, and immunofluorescence and urodynamic tests. Only a few families were able to access all the tests required for each case. Kidney transplant has been authorised in Senegal since 2015, but was not yet effective at the time of our study. We conducted a descriptive and analytical retrospective study over the period from January 2015 to December 2022. All cases of CTIN in children under 16 years of age were included in the study. CTIN was considered in patients with suggestive clinico-biological and radiological syndromes and/or lesions of interstitial fibrosis and tubular atrophy in renal biopsy with or without genetic addition. The aetiology was determined on the basis of the disease phenotype in most cases by comparing the clinical and paraclinical data recorded in a specific questionnaire. The case was excluded if the diagnosis of CTIN could not be established. Data were entered using Epi info version 7 and analysed using SPSS version 21. In the descriptive analysis, the qualitative variables were expressed as number and percentage and the quantitative variables as average with standard deviation, extreme values and median. In the analytical study, the incidence of end stage renal failure and death were compared by variable. The statistical tests used were the Khi2 or Fisher test for percentage comparison and the Student t test for average comparison. The difference was statistically significant if the p-value was strictly less than 0.05.


Results

At the end of the survey, 64 cases of CTIN were recorded in 709 children with chronic kidney disease. The hospital prevalence was 9% (64/709), which corresponds to an average of 08 cases per year in the department. The average age of children at onset of symptoms was 5.5 ± 5.3 years with a median age of 4 years and extremes of 0 and 15 years. The average age at admission to paediatric nephrology was 6.4 ± 4.4 years with a median of 5 years, corresponding to an average diagnostic pathway of 1 year? The gender ratio (M/F) was 2.4 (45/19). 73.4% (47/64) of the children were coming from Dakar region. Consanguinity was found in 11% (7/64) of cases. The reasons for consultation as well as biological blood and urine findings are listed (Tables 1,2). Bacteriological examination of urine was positive in 11% (7/64) of cases and detected Escherichia coli in 42.8% (3/7) of cases. Ultrasound examination revealed nephrocalcinosis was present in 28.1% (18/64) of cases, urinary tract malformation in 17.2% (11/64) of cases, and an obstructive intra-bladder stone in an uroscanner- confirmed case (Figure 1). 


Figure 1: Ultrasound axial and sagittal section showing urosacnner-confirmed nephrolithiasis in a child with cystinuria: 1. Bladder, 2. Scan-confirmed lithiasis (red arrow), 3. Posterior shadow cone.



Figure 2: Corneal cystine deposits (blue arrows) in a child with cystinosis


Two children showed a cystine deposit on the cornea in an ophthalmologic slit-lamp examination (Figure 2). Crystalluria examination revealed 01 case of uric acid and 01 other case of cystine calculi. Renal biopsy confirmed mutilating interstitial fibrosis with glomerulosclerosis and tubular atrophy in 4 children during nephronophthisis (Figure 3).