Immunostaining showing<unk>  in the glomerulus of a patient with Henoch-Schönlein nephritis. The pathophysiology, signs and symptoms, and treatment of<unk> . The disease derives its name from deposits of immunoglobulin A <unk>  in a granular pattern in the mesangium (by immunofluorescence), a region of the renal glomerulus. The mesangium by light microscopy may be hypercellular and show increased deposition of extracellular matrix proteins. In terms of the renal manifestation of Henoch–Schönlein purpura, it has been found that although it shares the same histological spectrum as<unk> , a greater frequency of severe lesions such as glomerular necrosis and crescents were observed. Correspondingly, HSP nephritis has a higher frequency of glomerular staining for fibrin compared with<unk> , but with an otherwise similar immunofluorescence profile. There is no clear known explanation for the accumulation of the<unk> . Exogenous antigens for<unk>  have not been identified in the kidney, but it is possible that this antigen has been cleared before the disease manifests itself. It has also been proposed that<unk>  itself may be the antigen. A recently advanced theory focuses on abnormalities of the<unk> 1 molecule.<unk> 1 is one of the two immunoglobulin subclasses (the other is IgD) that is O-glycosylated on a number of serine and threonine residues in a special proline-rich hinge region. Aberrant glycosylation of<unk>  appears to lead to polymerisation of the<unk>  molecules in tissues, especially the glomerular mesangium. 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<unk> ephritis. However, human studies have found that degalactosylation of<unk> 1 occurs in patients with<unk>  in response only to gut antigen exposures (not systemic), and occurs in healthy people to a lesser extent. This strongly suggests degalactosylation of<unk> 1 is a result of an underlying phenomenon (abnormal mucosal antigen handling) and not the ultimate cause of<unk> . Prevailing evidence suggests that both galactose-deficient o-glycans in the hinge region of<unk> 1 and synthesis and binding of antibodies against<unk> 1 are required for immunoglobulin complexes to form and accumulate in glomeruli. From the fact that<unk>  can recur after renal transplant, it can be postulated that the disease is caused by a problem in the immune system rather than the kidney itself. Remarkably, the<unk> 1 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. This, too, suggests an immune pathology rather than direct interference by outside agents. Natural history Since<unk>  commonly presents without symptoms through abnormal findings on urinalysis, there is considerable possibility for variation in any population studied depending upon the screening policy. Similarly, the local policy for performing kidney biopsy assumes a critical role; if it is a policy to simply observe patients with isolated bloody urine, a group with a generally favourable prognosis will be excluded. If, in contrast, all such patients are biopsied, then the group with isolated microscopic hematuria and isolated mesangial<unk>  will be included and improve the prognosis of that particular series. Nevertheless,<unk> , which was initially thought to be a benign disease, has been shown to not be a benign disease, particularly if the patient presents with an aggressive form. 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. In general, the entry into chronic kidney failure is slow as compared to most other glomerulonephritides – occurring over a time scale of 30 years or more (in contrast to the 5 to 15 years in other glomerulonephritides), however, in aggressive Berger's disease the time scale is within 5–10 years and often sooner. This may reflect the earlier diagnosis made due to frank hematuria. Complete remission of aggressive Berger's disease, occurs rarely in adults. In about 5% of cases, however, there is a higher chance of remission with non-aggressive Berger's disease (this is estimated to be around 7.4% of cases). There is a high chance of relapse, particularly with aggressive Berger's disease. However, given the evolution of this disease, the longer term (10–20 years) outcome of such patients is not yet established. Overall, the current 10-year survival rate for aggressive Berger's disease is 25% and 73% for non-aggressive Berger's disease.
IgA nephropathy
Analgesic nephropathy
Mesoamerican nephropathy
Malarial nephropathy
Shunt nephritis
Sickle cell nephropathy
Reflux nephropathy
Membranous glomerulonephritis