Mentorship and Collaboration to Better Understand Childhood IgA Nephropathyjbrown
Alexandra CAMBIER, YNC member, associate professor of pediatric nephrology (MD-PhD), Sainte Justine Hospital, Montréal University
Université de Paris, Paris, France ; Centre de Recherche sur L’inflammation (CRI); INSERM U1149, Paris, France
IgA nephropathy (IgAN) is one of the most common forms of primary glomerulonephritis in children and adolescents worldwide . In more than fifty percent of cases, patients with IgAN do not have any symptoms, and the diagnosis is made after an incidental finding of microscopic hematuria, hypertension, sub-normal glomerular filtration rate (GFR), or proteinuria [2-4]. Physicians have long considered childhood IgAN (cIgAN) a benign entity subject to remission and occasionally late relapse during adulthood . Adult IgAN, on the other hand, is considered a serious manifestation, with 15–40% of patients reaching end-stage renal disease (ESRD), depending on the region . However, the prognosis of cIgAN is just as severe as in adults: at ten-year follow-up, 10 to 13% of children will reach ESRD, and within 20 years, 20 to 30% will have ESRD [5, 7, 8].
A growing body of evidence suggests that IgAN is an immune complex-mediated glomerulonephritis resulting from the generation of IgA1 with aberrant glycosylation. Studies since the 1990s have revealed three key factors in the pathogenesis of IgAN, namely galactose-deficient IgA1 (Gd-IgA1), anti-IgA autoantibodies, and soluble IgA Fc receptor (sCD89) , (Figure 1).
These circulating immune complexes biomarkers have been identified as risk factors for adult IgAN progression but have not yet been characterized in cIgAN and could become targets for new therapies [10-13]. CIgAN differs from IgAN in that it presents as acute glomerulonephritis rather than chronic glomerulonephritis. Proteinuria in cIgAN is a marker of glomerular proliferative lesions, whereas its presence in adults often reflects chronic lesions [14, 15]. Since children have a long life expectancy, there is a need to describe more precisely the clinical particularities of cIgAN and find specific pathogenic factors for prognosis to elaborate treatment  targeting inflammatory processes and proliferative lesions in cIgAN. This requires extensive data collection and research collaboration.
The Young Nephrologists Committee, through its Research and Mentorship subcommittees, actively helps young ISN members develop their research careers and foster collaboration. The recently relaunched ISN Mentorship Program fosters expertise-sharing, expertise-building relationships, and project management in the field of nephrology and research for early-career nephrologists. Through this program, ISN members connect with the ISN global community to participate in program research, elaborate databases, and build mutual learning partnerships to raise understanding of the global nature of kidney health. This can be extremely useful for those working in rare diseases like childhood IgAN.
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