IgA nephropathy in children and in adults: two separate entities or the same disease?

IgA nephropathy (IgAN) is observed in subjects of any age, however perspective and management of this disease are different between adult and pediatrician Nephrologists. Most children with IgAN present with gross hematuria rapidly vanishing or persistent mild microscopic hematuria, which rarely progresses to end stage renal disease (ESRD) over the pediatric observation. The perspective of IgAN in adults is of a slowly progressive glomerular disease with 30-40% probabilities to reach ESRD. However, mild cases of IgAN in children might be missed with manifestation of irreversible damage only decades after the true onset, as 50% of subjects with IgAN enter renal replacement treatment before the age of 50 years. In both adults and children the assessment of risk profile is crucial to avoid overtreatment in benign cases or institute a prompt and valid therapy in potentially progressive cases. In case of common risk factors, new therapeutic opportunities tested in adults might be applied to children with the expectation of similar results. If IgAN is the same disease in spite of different clinical profiles in children and adults, an early intervention may be the correct way to prevent progression decades later. On the contrary, if we are dealing with different clinical entities, the treatment in pediatric and in adult settings must be kept apart. This review addresses to report similarities and differences of IgAN across the life periods in order to reason on the application of newly offered treatments over the entire spectrum of this disease or in focused age indications.