Pathogenesis of this disease has not been elucidated. As the patient's skin
and liver disease can be detected IgA deposition , suggestive of systemic
disease . As in the glomerular mesangial area and capillaries may have granular
IgA and C3 deposition , suggesting that immune complex pathogenesis . Current
research around the antigen via mucosal capacity mucosal barrier for defects ;
IgA structure is defective , and immune function is defective in such areas .
The early studies have suggested that the disease might be mucosal IgA
deposition derived . However, recent studies using a highly specific technique
confirmed that the disease is deposited IgA1, the system mainly derived
primarily from the bone marrow and lymphatic system generated ; mucosal IgA2
derived mainly seen in hepatic renal small ball sclerosis in IgA deposition . In
patients with this disease can also be seen in the total cycle IgA1 and IgA1
-containing immune complexes increased, IgA1 produced in the bone marrow plasma
cells and the formation of multimers based. In this disease may be found to
exist in renal tissue of J chain , it is suggested IgA deposition polymer ; while the secretion block is very rare. Nevertheless, the existing data is not yet finalized the disease IgA sediment sources.
A large number of antigens, including a variety of viruses and a variety of food antigens in patients with this disease was detected in the mesangial area , and often accompanied by IgA1 deposition . The antigen is also an IgA1. Since these antibodies may also be present in the normal cycle, the antigen specificity or no characteristic .
There is evidence suggesting that the disease has an immune dysregulation . The disease IgA1 -containing circulating immune complexes , found how cohesive IgA1 rheumatoid factor ; anti- α heavy chain Fab fragment of IgG antibodies increased and decreased IgM antibodies . Interestingly HIV infection there is a similar pattern anti-immunoglobulin , IgA deposition does not occur kidneys . This proves that only the presence of circulating autoantibodies , not cause mesangial IgA deposition . Also present was also found two kinds of anti-endothelial cell antibodies ( an IgG). The disease often C3 deposition in renal tissue , suggesting that activation of the alternative pathway of complement . However, IgA itself has no ability to activate complement , IgA immune complexes , although the alternative pathway of complement activation may be , but it combines the ability to complement C3b and weak. Generally considered to complement activation and kidneys forming membrane attack complex , the need for IgG-IgA complexes , but the tissues of the kidney disease IgA and C3 deposition and no deposition of IgG or IgM is very common. Therefore , the disease of complement activation mechanism is unclear. Immune cells are also involved in the pathogenesis . The disease has been found to be of T helper cells (CD4) and T suppressor cells increased (CD8) reduction ; has a conversion IgM synthesis of IgA synthesis Ta4 cells increased Sa1 relating to the frequency of allele also increased ; cause IgA the same type of conversion TGFβ, IgA-producing B lymphocytes to promote differentiation mediated by IL-5 and IL-4 produced IgA formation were increased . Although T cells and B cells are involved in the increase in IgA synthesis process, but IgA synthesis increased mesangial IgA deposition is not the reason , because in patients with multiple myeloma IgA rare organized IgA deposition . Therefore , the structure - Immunology / chemical abnormality was probably the reason mesangial IgA deposition .
The disease patient sera and mesangial can be detected in bovine serum albumin polyclonal anti- idiotypic antibodies , the titer associated with hematuria . Recently , it was from a patient with renal cortex and glomerular IgA been obtained in the five kinds of monoclonal antibodies against gene , which the patient serum or plasma cell response is poor , and the kidney tissue with a high response rate , suggesting that the kidney deposited with the polyclonal nature of the abnormal IgA antibody . In addition, patients with this disease are found β1, 3 - galactosyltransferase defects change IgA1 or complexes containing IgA1 clearance rate, resulting in mesangial IgA1 deposition .
In summary , the deposition of the antigen , with or without cell-mediated immune response , IgA complex formation rate and a IgAFc receptors mesangial cells or neutrophils in the overall removal efficiency for the pathogenesis and cytokines and growth factors are mainly involved in mesangial proliferation and hardening mechanisms .
