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11–14 APRIL, 2018, HELSINKI, FINLAND
11:58–12:01
S24-3 (PP)
COMPOSITION OF STONES AND METABOLIC RISK
FACTORS IN INFANTS. AN ENDEMIC COUNTRY
EXPERIENCE
Mirza Naqi ZAFAR
Sindh Institute of Urology and Transplantation, Pathology, Karachi, PAKISTAN
PURPOSE
Pediatric urolithiasis remains endemic in low resource countries where infants constitute 17–40 %
of all children with urolithiasis. This study reports socio-economic factors, medical history, chemical
composition and metabolic risk factors in 1437 infants upto the age of 2 years from an endemic
country.
MATERIAL AND METHODS
Between 1982–2016, 1437 infants presented to our institute with 1217 stones. Patients were
evaluated for demographics, blood and 24 h urine for calcium, magnesium, phosphate, uric acid,
electrolytes and additional protein, citrate, ammonia and oxalate in urine. Chemical composition of
stones was analyzed by Fourier transformation infrared spectroscopy (FTIR). All reported values
were two sided and statistical significance was considered at p value <=0.05.
RESULTS
The mean age of infants was 17.5±6.24 months with a M:F ratio of 5:1. Nearly half (50 %) of the
infants were rural dwellers, 92 % belonged to low socio-economic class and 70 % were malnour-
ished. A history of chronic diarrhoea was reported in 17 % and urinary tract infections in 8 %. Overall
frequency of compounds in stones showed Ammonium acid urate (AAU) in 75 %, Calcium Oxalate
(CaOx) in 40 %. Uric Acid (UA) in 12 %, Calcium phosphate apatite (CaP) in 7 %, Magnesium
ammonium phosphate (Struvite) in 5 %), Cystine in 1 % and Xanthine in 5 %. Urinary metabolic
abnormalities showed Hypocitraturia in 84 %, hyperoxaluria in 26 %, hyperuricosuria in 52 %, hy-
perammonuria in 14 %, hyponatriuria in 49 % and hypovolemia in 50 %.
CONCLUSIONS
Our study has shown that AAU is a major component of stones in infants where the main risk factors
are poverty, malnutrition, diarrheal diseases and dehydration.