Clinical outcome of children with primary distal renal tubular acidosis.

Objective: To evaluate the clinical course of children with primary distal renal tubular acidosis and to determine parameters correlated with the outcomes.

Material And Method: A retrospective review of medical records was carried out. The parameters at initial diagnosis and the last visit were collected including height standard deviation score (SDS), weight SDS, ultrasonography of kidneys, serum electrolytes, urine electrolytes, urine calcium to urine creatinine ratio (urine Ca/Cr), serum creatinine, bicarbonate dosage and glomerular filtration rate estimated by Schwartz's formula (eGFR).

Results: Fifteen patients were included with median follow-up time of 12 years (range 4.5 to 19 years). Median age at diagnosis was 3 years (range 0.25 to 9 years). At the last visit, median height SDS increased significantly from -3.1 to -0.8 (p = 0.04). Height SDS at the last visit correlated with age at diagnosis (r = -0.54, p = 0.038) and serum bicarbonate at the last visit (r = 0.68, p = 0.008). Moreover, at the last visit, eGFR correlated with urine Ca/Cr (r = -0.84, p = 0.001).

Conclusion: After treatment, growth of patients improved satisfactorily. The outcomes were associated with age at diagnosis, compliance of bicarbonate therapy and urine Ca/Cr at the last visit.