Article Type : Research Article
Authors : Keita Y, Faye M, Dione S, Ndongo AA, Faye AA, Sow A, Boiro D, Faye M, Bacary BA, Seye MD, Takam BL, Seck N, Abou BA, Indou Deme LY, Thiongane A, Fatou LY, Lemrabott AT, Gueye M and Sylla A
Keywords : Polyuria-polydipsia; Nephronophthisis; Nephrocalcinosis; Tubulopathies; Chronic kidney disease
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.
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.
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.
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).