Efficacy and safety of an innovative prolonged-release combination drug in patients with distal renal tubular acidosis: an open-label comparative trial versus standard of care treatments

BACKGROUND

Distal renal tubular acidosis (dRTA), due to impaired acid secretion in the urine, can lead to severe long-term consequences. Standard of care (SoC) oral alkalizers, requiring several daily intakes, are currently used to restore normal plasma bicarbonate levels. A new prolonged-release formulation, ADV7103, has been developed to achieve a sustained effect with an improved dosing scheme.

METHODS

In a multicenter, open-label, non-inferiority trial (n = 37), patients with dRTA were switched from SoC to ADV7103. Mean plasma bicarbonate values and proportion of responders during steady state therapy with both treatments were compared, as were other blood and urine parameters, as well as acceptability, tolerability, and safety.

RESULTS

When switching from SoC to ADV7103, the number of daily intakes was reduced from a median of three to twice daily. Mean plasma bicarbonate was increased and non-inferiority of ADV7103 was demonstrated (p < 0.0001, per protocol), as was statistical superiority (p = 0.0008, intention to treat [ITT]), and the response rate increased from 43 to 90% with ADV7103 (p < 0.001, ITT). Urine calcium/citrate ratio was reduced below the threshold for risk of lithogenesis with ADV7103 in 56% of previously non-responders with SoC (p = 0.021, ITT). Palatability was improved (difference [95% CI] of 25 [10.7, 39.2] mm) and gastrointestinal discomfort was reduced (difference [95% CI] of - 14.2 [- 25.9, - 2.6] mm) with ADV7103.

CONCLUSIONS

Plasma bicarbonate levels and response rate were significantly higher with ADV7103 than with SoC. Urine calcium/citrate ratio, palatability, and gastrointestinal safety were significantly improved, supporting the use of ADV7103 as first-line treatment for dRTA.

TRIAL REGISTRATION

Registered as EudraCT 2013-002988-25 on the 1st July 2013 Graphical abstract.

Correction to: Efficacy and safety of an innovative prolonged-release combination drug in patients with distal renal tubular acidosis: an open-label comparative trial versus standard of care treatments

The published version of the article unfortunately contained a mistake.

Hypertensive encephalopathy as a late complication of autonomic dysreflexia in a 12-year-old boy with a previous spinal cord injury

The scope of paediatric autonomic disorders is not well recognised, and paediatricians seem to be generally unaware of the complexity and diversity of their clinical manifestations. We report a 12-year-old boy presenting with hypertensive encephalopathy caused by autonomic dysreflexia.

CONCLUSION

This observation emphasises the importance of the recognition of this rare autonomic disorder, which can have potentially life-threatening neurological complications.

Molecular characterization of cystinuria in south-eastern European countries

Cystinuria is an autosomal recessive disorder caused by defective transport of cystine and dibasic amino acids in the proximal renal tubules and small intestine. So far, more than 128 mutations in SLC3A1 gene, and 93 in SLC7A9 gene have been described as a cause of cystinuria. We present a molecular characterization of the cystinuria in 47 unrelated south-east European families. The molecular methodology included direct sequencing, single strand conformational polymorphism, and restriction fragment length polymorphism. A total of 93 (94.9 %) out of 98 unrelated cystinuric chromosomes have been characterized. Mutations in SLC3A1 gene account for 64.3 % and in SLC7A9 gene for 30.6 % of the cystinuric chromosomes. Ten different mutations in SLC3A1 gene were found, and two of them were novel (C242R and L573X), while in SLC7A9 gene seven mutations were found, of which three were novel (G73R, V375I and c.1048_1051delACTC). The most common mutations in this study were T216M (24.5 %), M467T (16.3 %) and R365L (11.2 %) in SLC3A1 and G105R (21.4 %) in SLC7A9 gene. A population specificity of cystinuria mutations was observed; T216M mutation was the only mutation present among Gypsies, G105R was the most common mutation among Albanians and Macedonians, and R365L among Serbs. The results of this study allowed introduction of rapid, simple and cost-effective genetic diagnosis of cystinuria that enables an early preventive care of affected patients and a prenatal diagnosis in affected families.

Epidemiology of chronic kidney disease in children in Serbia

BACKGROUND

The epidemiological information from well-defined populations regarding childhood chronic kidney disease (CKD), particularly those concerning non-terminal stages, are scanty. The epidemiology of CKD in children is often based on renal replacement therapy (RRT) data, which means that a considerable number of children in earlier stages of CKD are missed as they will reach end-stage renal disease (ESRD) in adulthood. Here, we report the basic epidemiological data on childhood CKD in Serbia, gathered over the 10-year period of activity of the Serbian Pediatric Registry of Chronic Kidney Disease.

METHODS

Since 2000-09, data on incidence, prevalence, aetiology, treatment modalities and outcome of children aged 0-18 years, with CKD Stages 2-4 and CKD Stage 5, were collected by reporting index cases from paediatric centres.

RESULTS

Three hundred and thirty-six children were registered (211 boys, 125 girls, male/female ratio 1.7). The median age at registration was 9.0 years [interquartile range (IQR) 3-13]. Median follow-up was 4.0 years (IQR, 1-9). The median glomerular filtration rate (GFR) at the time of the registration was 39.6 mL/min/1.73m(2) (IQR, 13.8-65.4). Median annual incidence of CKD 2-5 stages was 14.3 per million age-related population (p.m.a.r.p.), while those of CKD 2-4 or CKD 5 were 9.1 and 5.7 p.m.a.r.p., respectively. The median prevalence of CKD 2-5 was 96.1 p.m.a.r.p., 52.8 p.m.a.r.p. in CKD 2-4 and 62.2 p.m.a.r.p. in CKD 5. The main causes of CKD were congenital anomalies of kidney and urinary tract and hereditary nephropathies. Kidney survival was the worst in children with glomerular diseases and in those with advanced CKD. Haemodialysis was the most common first modality of RRT. Mortality rate was 4.5%, mainly due to cardiovascular and infectious complications.

CONCLUSIONS

Epidemiology of paediatric CKD in Serbia is similar to that reported from developed European countries. The knowledge of the epidemiology of earlier stages of CKD is essential for both institution of renoprotective therapy and planning of RRT, a fact of paramount importance in countries with limited resources.

Microalbuminuria in children with vesicoureteral reflux

Vesicoureteral reflux (VUR) is a common congenital anomaly of the urinary tract that may be inherited. Reflux of infected urine may cause scarring in susceptible kidneys with the potential to compromise renal function. The aim of the study was to evaluate the possible influence of different grades of VUR on glomerular damage using microalbuminuria as a parameter. Children with VUR detected by voiding cystourethrography (VCUG) were investigated. According to the grade of VUR, patients were separated into three groups. The first group included 12 children with VUR grade I-II. The second group consisted of 12 children with grade III of VUR. Patients with VUR grade IV-V (n = 11) were members of the third group. The control group consisted of 17 healthy children. Microalbuminuria was examined in samples of morning urine specimens using a microalbumin/creatinine reagent kit. Serum urea, creatinine levels and creatinine clearance (CCR) were measured as markers of renal function. The mean value of microalbumin excretion in the third group showed a statistically significant increase (p < 0.001) compared to all other groups. CCR in the third group was statistically significantly decreased (p < 0.05) in comparison to the group of healthy children. There were no statistically significant changes of microalbumin excretion and CCR in the first and second group compared to control values. We discussed the presence of microalbuminuria and decrease of CCR in children with high grade of VUR as a possible consequence of retrograde urine flow (intrarenal reflux), glomerulosclerosis, and consecutive hyperfiltration.