[3] IgA vasculitis presents with a characteristic purpuric skin rash, arthritis, and abdominal pain, and occurs more commonly in children.

Electron microscopy confirms electron-dense deposits in the mesangium that may extend to the subendothelial area of adjacent capillary walls in a small subset of cases, usually those with focal proliferation.

[citation needed] The disease derives its name from deposits of immunoglobulin A (IgA) in a granular pattern in the mesangium (by immunofluorescence), a region of the renal glomerulus.

In terms of the renal manifestation of Henoch–Schönlein purpura, it has been found that although it shares the same histological spectrum as IgA nephropathy, a greater frequency of severe lesions such as glomerular necrosis and crescents were observed.

[5] A similar mechanism has been claimed to underlie Henoch–Schönlein purpura, a vasculitis that mainly affects children and can feature renal involvement that is almost indistinguishable from IgA nephritis.

[6] This strongly suggests degalactosylation of IgA1 is a result of an underlying phenomenon (abnormal mucosal antigen handling) and not the ultimate cause of IgA nephropathy.

Prevailing evidence suggests that both galactose-deficient o-glycans in the hinge region of IgA1 and synthesis and binding of antibodies against IgA1 are required for immunoglobulin complexes to form and accumulate in glomeruli.

Remarkably, the IgA1 that accumulates in the kidney does not appear to originate from the mucosa-associated lymphoid tissue (MALT), which is the site of most upper respiratory tract infections, but from the bone marrow.

[8][9] Since IgA nephropathy commonly presents without symptoms through abnormal findings on urinalysis, there is considerable possibility for variation in any population studied depending upon the screening policy.

Though most reports describe Berger's disease as having an indolent evolution towards either healing or renal damage, a more aggressive course is occasionally seen associated with extensive crescents, and presenting as acute kidney failure.

However, recent findings have uncovered a significant genetic component that influences both the regulation of serum IgA levels and susceptibility to the disease.

Notably, a study conducted by Liu (2022) highlighted ancestral differences, revealing that individuals of African descent consistently have higher serum IgA levels.

These findings suggest a complex interplay of genetic factors in regulating IgA levels and contributing to the susceptibility of various immune, kidney, and metabolic disorders.

Another study utilized a two-sample Mendelian randomization (TSMR) approach to explore causal relationships between IgAN and several factors, including neuropsychiatric disorders and dietary intake (Lin, 2025).

Further research is needed to confirm these associations and understand the underlying mechanisms, which could inform prevention strategies for individuals at risk of IgAN.

Moreover, adopting a healthy diet that limits alcohol and includes protective foods such as cheese, cereal, and sushi may reduce the likelihood of developing IgAN.

Early intervention through lifestyle modifications, regular monitoring of kidney function, and stress management may also help reduce the onset of neuropsychiatric conditions linked to IgAN, such as depression.

However, in patients with aggressive Berger's disease 6 months regimen of steroids in addition to other medications may lessen proteinuria and preserve renal function.

[citation needed] Cyclophosphamide (traded as endoxan and cytoxan) and Isotretinoin have commonly been used, often with anti-platelet/anticoagulants in patients with Aggressive Berger's disease, however, the side effect profile of these drugs, including long term risk of malignancy and sterility, made them an unfavorable choice for use in young adults.

However, one recent study, in a carefully selected high risk population of patients with declining GFR, showed that a combination of steroids and cyclophosphamide for the initial 3 months followed by azathioprine for a minimum of 2 years resulted in a significant preservation of renal function.

[15][16] The events that tend to lead to progressive kidney failure are not unique to IgA nephropathy, and non-specific measures to reduce the same would be equally useful.

[citation needed] In December 2021, budesonide (Tarpeyo) was approved for medical use in the US to reduce proteinuria in adults with primary IgA nephropathy at risk of rapid disease progression.

[19] Male sex, proteinuria (especially > 2 g/day), hypertension, smoking, hyperlipidemia, older age, familial disease and elevated creatinine concentrations are markers of a poor outcome.

ACE gene polymorphism has recently been shown to have an impact with the DD genotype associated more commonly with progression to kidney failure.

School children in Japan and army recruits in Singapore undergo routine urinalysis, and any suspicious abnormality is pursued with a kidney biopsy, which might partly explain the high observed incidence of IgA nephropathy in those countries.

However, more than 90% of cases of IgA nephropathy are sporadic, with a few large pedigrees described from Kentucky and Italy (Online Mendelian Inheritance in Man (OMIM): 161950).

[citation needed] William Heberden the elder first described the disease in 1801 in a 5-year-old child with abdominal pain, hematuria, hematochezia, and purpura of the legs.