Chemical Composition Of Stones In Paediatric Urolithiasis

BACKGROUND

Chemical composition of stones is one of the important diagnostic criteria for aetiology of stone formation and treatment to prevent recurrence. This paper reports composition of stones in children at a tertiary hospital by Fourier Transformation Infrared Spectroscopy (FTIR).

METHODS

Between January-June 2015, 412 urinary stones from children were analysed by FTIR. Chi-square tests were used for the comparison of categorical measurements between groups. All reported values were 2-sided and statistical significance was considered at p-value ≤0.05.

RESULTS

Of the 412 stones, 263 (63.8%) were renal, 101(24.5%) bladder and 48 (11.7%) ureteric. The mean age of children was 7.15±4.13 years with a M:F ratio 2.4:1. Of the 412 stones, 144(34.9%) were pure stones composed of one compound and 268(65.1%) were mixtures. Frequency of compound in stones was Ammonium Acid Urate (AAU) (65%), Calcium Oxalate (CaOx) (76.9%), Uric Acid (5%), Calcium Phosphate Apatite (7%), Whitlockite (8.4%), Struvite (4%), Cystine (0.72%) and Xanthine (2.11%). Frequency of compounds analysed in three ages groups 0-5, 6-10 and 11-15 years showed high frequency of AAU (73%) in 0-5 years as compared to (60%) in 11-15 years (p<0.018). CaOx (90%) in 11-15 as compared to (62.5%) in 0-5 years (p<0.001). Bladder stones were more prevalent in children 0-5 years (32%) vs 19% in 11-15 years (p<0.004) while renal were 75% in 11-15 years and 54% in 0-5 years (p<0.04).

CONCLUSIONS

AAU stones known to be associated with malnutrition and chronic diarrhoea are highly prevalent in paediatric stones formers in our population in the kidney, bladder and ureter.

Metabolic risk factors in pediatric stone formers: a report from an emerging economy

The goal of this study was to investigate metabolic risk factors in pediatric stone formers in an emerging economy. A prospective, data collection enrolled 250 children age <1-15 years at our center. Risk factors were evaluated by gender and in age groups <1-5, 6-10 and 11-15 years. 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. All reported values were two sided and statistical significance was considered at p value ≤0.05. The mean age at diagnosis was 7.50 ± 3.56 years with a male to female ratio of 1.84:1. A family history of urolithiasis was found in 41 (16.4 %), urinary tract infection in 18 (7 %) and chronic diarrhea in 75 (30 %). Hypercalcemia was seen in 37 (14.8 %), hyperuricemia in 23 (9.2 %) and hyperphosphatemia in 6 (2.4 %). Urinary metabolic abnormalities were identified in 248 (98 %) of the cases. Hypocitraturia was found in 207 (82.8 %), hyperoxaluria in 62 (26.4 %), hyperuricosuria in 82 (32.8 %), hypercalciuria in 51 (20.4 %), hyperphosphaturia in 46 (18.4 %), hyperammonuria in 10 (4 %), hypocalciuria in 82 (32.8 %), and hypovolemia in 73 (29.2 %). Risk factors were similar between genders except higher rates of hyponatriuria, hypophosphaturia, and hypocalciuria in females. Hyperuricosuria, hyponatriuria, and hypovolemia were highest in 1-5 years (52, 49, 49 %) as compared to (18, 21, 12 %) those in 11-15 years (p < 0.001), respectively. This study shows that careful metabolic analysis can identify risk factors in 98 % of the children where appropriate metaphylaxis can be undertaken both for treatment and prevention of recurrence.

Cystatin C levels in healthy kidney donors and its correlation with GFR by creatinine clearance

OBJECTIVE

To determine Serum Cystatin C (S.CysC) levels in healthy potential kidney donors and its correlation with Serum Creatinine (S.Cr), Glomerular filtration rate (GFR) by 24 hour urinary Creatinine clearance (CCL) and GFR by formulae of Cockcroft Gault (CCG) and Modification of diet in Renal Disease (MDRD).

METHODS

A Cross sectional study was conducted at Sindh Institute of Urology and Transplantation (SIUT), Karachi, between June and December 2012. One hundred and three potential healthy kidney donors were enrolled in the study to measure their S.CysC and correlate it with S.Cr, CCL and GFR by CCG and MDRD. Statistical analysis was done by SPSS 17.

RESULTS

The mean age of the healthy kidney donors was 32.19 + 8.27 years with a M:F ratio of 1.86:1. The mean Serum Creatinine (S.Cr) was 0.86 + 0.18 mg/dl and mean S.CysC was 0.88 + 0.12 mg/dl. S.CysC showed significant correlation with S.Cr (r = 0.78, p < 0.001), CCL (r = 0.67, p < 0.001), GFR CCG (r = 0.54, p < 0.001) and GFR MDRD (r = 0.67, p < 0.001). Correlation of S.CysC was better than S.Cr for CCL, S.Cr (0.60) vs S.CysC (0.67) and GFR CCG, S.Cr (0.41) vs S.CysC (0.54). Correlation was comparable for MDRD, S.Cr (0.67) vs S.Cys (0.67).

CONCLUSION

S.CysC is better marker of kidney function in potential healthy kidney donors. It is a reliable, convenient and economical marker that can be used especially in routine clinical practice.