IgA Nephropathy - Pathophysiology


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. The mesangium by light microscopy may be hypercellular and show increased deposition of extracellular matrix proteins.

There is no clear known explanation for the accumulation of the IgA. Exogenous antigens for IgA 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 IgA itself may be the antigen.

A recently advanced theory focuses on abnormalities of the IgA1 molecule. IgA1 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. Deficiency of these sugars appears to lead to polymerisation of the IgA molecule in tissues, especially the glomerular mesangium. A similar mechanism has been claimed to underlie Henoch-Schönlein purpura (HSP), a vasculitis that mainly affects children and can feature renal involvement that is almost indistinguishable from IgA nephritis. However, human studies have found that degalactosylation of IgA1 occurs in patients with IgA nephropathy in response only to gut antigen exposures (not systemic), and occurs in healthy people to a lesser extent. 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.

From the fact that IgAN 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 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. This, too, suggests an immune pathology rather than direct interference by outside agents.

Read more about this topic:  IgA Nephropathy

Other articles related to "pathophysiology":

Pathophysiology - Uses
... Pathophysiology is a required area of study for nearly all healthcare professional school programs (medical, dental, physician assistant, occupational therapy, physical therapy, nurse practitioner, pharmacy, nursing ...
University Of Ostrava - Faculties and Departments - Faculty of Medicine - Department of Physiology and Pathophysiology
... The Department of Physiology and Pathophysiology is divided into Institute of Physiology and Institute of Pathophysiology ... to providing undergraduate teaching, the Department of Physiology and Pathophysiology carries out scientific research and produces expert reports ...
Tension Headache - Cause
... suggest that NO may play a key role in the pathophysiology of CTTH ... spinal nucleus, thalamus, and cerebral cortex) is believed to be involved in the pathophysiology of chronic tension-type headache ... inhibitory systems may also play a role in the pathophysiology of chronic tension-type headache ...
Atrax Morgue - Partial Discography
... Cass) Slaughter Productions 1995 Homicidal Texture (Cass) Slaughter Productions 1995 Pathophysiology (Cass) Old Europa Cafe 1995 Untitled (Cass) Slaughter Productions 1995 ... Casa Dalle Finestre Che Ridono (CDr) Slaughter Productions 2002 Pathophysiology (CDr) Transf/Order 2002 Sweetly (CDr, Album) Spatter 2002 Death - Orgasm Connector (CD) Slaughter ...