Altered pattern of connectivity in serum immunoglobulins from pemphigus vulgaris patients

Altered pattern of connectivity in Chagas disease

It has been proposed that natural autoreactivity plays a physiological role in the immune system by connecting all these clones (Id/anti-Id) and forming a dense and highly regulated network. In the present work, we analyzed the connectivity pattern in Chagas disease. Serum samples of 20 chronic chagasic cardiopathy (CCC) patients with dilated cardiopathy, 20 infected-asymptomatic subjects (IAS), and 20 healthy seronegative controls (H) were tested. Pattern of connectivity was distinguishable from that of healthy donor and those with CCC and IAS. This suggests that there are alterations in regulatory networks, inclusive being more evident in CCC patients than in IAS.

Connectivity patterns in tuberculosis and leprosy patients are indistinguishable from that of healthy donors

Connectivity, the self-defined interactions between antigen-recognising molecules in a network system can in part be assessed by measuring the reactivity of a given serum against an ordered set of immunoglobulin (Ig)G F(ab')2 fractions, separated by means of isoelectric focusing so that, the serum reactivity against the whole set of fractions defines a characteristic pattern of connectivity. Deviations from the normal condition (healthy donors) have so far been documented for two autoimmune diseases: systemic lupus erythematosus (SLE) and pemphigus vulgaris, as well as for human immunodeficiency virus (HIV)-1 infection. We tested here if bacterial infections lead to alterations in connectivity. In addition, we wanted to test if two antigenically related bacteria would produce similar or otherwise distinctive connectivity patterns. Connectivity analysis was applied on the sera from tuberculosis and leprosy patients and the sera from healthy donors were used as control. No statistically significant differences between the three groups studied were found. These results have implications for theories that set the origin of autoimmune diseases in microbial infections. To the best of our knowledge, this is the first attempt to analyze the connectivity status in bacterial infections.

Connectivity and HIV-1 infection: role of CD4(+) T-cell counts and HIV-1 RNA copy number

Following primary infection with human immunodeficiency virus (HIV)-1, antibodies against specific HIV-1 epitopes are elicited. However, non-HIV-1 specific antibodies, including autoantibodies, also arise. In fact, it has been proposed that such autoantibodies have an important role in the pathogenesis of HIV-1 infection. Because an imbalance in connectivity has been associated with autoimmune processes, we investigated the connectivity status of HIV-1-infected individuals. Moreover, we tested the possible role of viral load and CD4(+) T-cell counts, in connectivity, because these parameters appear to be important in the prognosis of HIV-1 infection. Results show that indeed, there is an alteration in connectivity in these patients, both for immunoglobulin (Ig)G and IgM, which is an immune alteration not previously identified in HIV-1 infection. In addition, our results show that viral load and CD4(+) T-cell counts are both equally important in defining the characteristic pattern of connectivity in HIV-1-infected individuals, and that neither is independently responsible for alterations in patient connectivity status.