This article will introduce you to the most common nephritis - IgA nephropathy

A 23-year-old male was found to have abnormal urine routine test during a physical examination, including 2+ red blood cells and + protein in urine, but he did not feel any discomfort. He repeated urine routine tests several times, and the red blood cells in urine were always positive. To further clarify the diagnosis, a renal puncture biopsy was performed, and a large amount of IgA deposition was found in the glomerular mesangial area. The renal lesions were mild and he was diagnosed with IgA nephropathy. So, what is IgA nephropathy?

What is IgA? IgA is immunoglobulin A, which is second only to IgG in normal human serum, accounting for 10% to 20% of serum immunoglobulin content. According to its immune function, it is divided into serum type and secretory type. When the body is infected, the human body produces IgA antibodies against microbial antigens. A large amount of IgA and IgA immune complexes are deposited in the glomerular mesangial area, activating the body's immune mechanism, thereby causing kidney damage.

What is IgA nephropathy? IgA nephropathy was first described by Berger in 1968. It is a group of glomerular diseases characterized by glomerular mesangial proliferation and significantly diffuse IgA deposition in the mesangial area. This disease is a common primary glomerular disease worldwide and a common type of primary glomerulonephritis in my country. Its clinical and pathological manifestations are diverse, and the clinical outcomes vary. Most patients present with benign hematuria and lifelong stable renal function, and 15% to 40% of patients may eventually progress to end-stage renal disease.

Why do people get IgA nephropathy? The exact pathogenesis of IgA nephropathy is not yet fully understood. It is generally believed that this disease is a complex disease affected by multiple genes and environmental factors. That is, individuals with genetic susceptibility, under the influence of environmental factors, trigger and activate the body's immune mechanism, thereby mediating renal inflammation and damage. Among them, genetic factors play an important role in the onset of IgA nephropathy. Epidemiological surveys have shown that some patients with IgA nephropathy have familial clustering, and familial IgA nephropathy accounts for 10% to 15% of all patients. Most of its inheritance is an incompletely penetrant autosomal dominant inheritance pattern.

How is IgA nephropathy diagnosed?

In life, if you have macroscopic hematuria after a cold or microscopic hematuria and/or asymptomatic proteinuria is found during physical examination, please go to the nephrology department of the hospital in time. The hematuria of this disease is glomerular (mainly malformed red blood cells), the proteinuria is high-molecular, medium-molecular or mixed proteinuria, and serum IgA may be elevated. During renal puncture biopsy immunopathological examination, granular immune complex precipitation dominated by IgA can be seen in the glomerular mesangial area, which is a necessary condition for the diagnosis of IgA nephropathy and is also the "gold standard" for diagnosis.