Immunoglobulin A glomerulonephropathy: A review

Abstract

In this editorial, we comment on the article by Meng et al published in the World Journal of Clinical Cases. We comprehensively review immunoglobulin A nephropathy (IgAN), including epidemiology, clinical presentation, diagnosis, and management. IgAN, also known as Berger's disease, is the most frequent type of primary glomerulonephritis (GN) globally. It is mostly found among the Asian population. The presentation can be variable, from microscopic hematuria to a rapidly progressive GN. Around 50% of patients present with single or recurring episodes of gross hematuria. An upper respiratory infection and tonsillitis often precede these episodes. Around 30% of patients present microscopic hematuria with or without proteinuria, usually detected on routine examination. The diagnosis relies on having a renal biopsy for pathology and immunofluorescence microscopy. We focus on risk stratification and management of IgAN. We provide a review of all the landmark studies to date. According to the 2021 KDIGO (kidney disease: Improving Global Outcomes) guidelines, patients with non-variant form IgAN are first treated conservatively for three to six months. This approach consists of adequate blood pressure control, reduction of proteinuria with renin-angiotensin system blockade, treatment of dyslipidemia, and lifestyle modifications (weight loss, exercise, smoking cessation, and dietary sodium restrictions). Following three to six months of conservative therapy, patients are further classified as high or low risk for disease progression. High-risk patients have proteinuria ≥ 1 g/d or < 1 g/d with significant microscopic hematuria and active inflammation on kidney biopsy. Some experts consider proteinuria ≥ 2 g/d to be very high risk. Patients with high and very high-risk profiles are treated with immunosuppressive therapy. A proteinuria level of < 1 g/d and stable/improved renal function indicates a good treatment response for patients on immunosuppressive therapy.

Keywords: Immunoglobulin A nephropathy; Glomerulonephritis; Nephritic syndrome; Angiotensin-converting enzyme inhibitor; Angiotensin receptor blocker; Systemic steroids; Mycophenolate mofetil

Core Tip: Immunoglobulin A nephropathy is the most common type of glomerulonephritis globally. The management approach differs based on the level of risk for renal disease progression. In low-risk settings, patients are treated with angiotensin system blockade, while patients with a high risk of progressive renal disease are treated with immunosuppressive therapy. Systemic steroids have been shown to have favorable outcomes when compared to the standard of care in high-risk patients. Unfortunately, steroids are associated with numerous side effects. In some studies, mycophenolate mofetil has been shown to have favorable outcomes when compared to steroids with a better safety profile.