The majority of C1q-binding IgG in sera of some patients with systemic lupus erythematosus (SLE) cosediments with monomeric IgG. This study was undertaken to provide definitive proof that the low-molecular weight C1q-binding IgG consists of autoantibodies to C1q. Monomeric C1q-binding IgG was isolated from five SLE plasmas by C1q affinity chromatography and gel filtration. All C1q-binding IgG p...

The significance of high serum concentrations of low molecular weight C1q (LMW-C1q) in patients with systemic lupus erythematosus (SLE) was studied. Concentrations of LMW-C1q were increased in SLE, but not in rheumatoid arthritis or acute poststreptococcal glomerulonephritis. Concentrations of LMW-C1q in SLE serum samples correlated with titres of anti-dsDNA and were inversely related to concen...

BACKGROUND The complement component C1q triggers activation of the classical immune pathway and can bind to adiponectin (APN). Recently, some studies have been reported that serum C1q-APN/total APN ratio correlates with atherosclerosis and coronary artery disease (CAD). We assessed the relationships between C1q related variables and the severity of CAD, and investigated the localization of the ...

BACKGROUND Lupus nephritis is considered to be a principal cause of morbidity and mortality in SLE. Few studies focus on the association between anti-C1q antibodies in circulation and renal C1q deposition in human lupus nephritis. In this study, we detected the serum levels of C1q, presence of anti-C1q antibodies in circulation, renal C1q deposition and further analyzed their associations with ...

Autoantibodies against complement C1q (anti-C1q) are frequently found in patients with systemic lupus erythematosus (SLE). They strongly correlate with the occurrence of severe lupus nephritis, suggesting a pathogenic role in SLE. Because anti-C1q are known to recognize a neoepitope on bound C1q, but not on fluid-phase C1q, the aim of this study was to clarify the origin of anti-C1q by determin...

C1q deficiency is a rare immunodeficiency, which is strongly associated with the development of systemic lupus erythematosus (SLE). A mutation in one of the C1q genes can either lead to complete deficiency or to low C1q levels with C1q polypeptide in the form of low-molecular weight (LMW) C1q. Patients with C1q deficiency mainly present with cutaneous and renal involvement. Although less freque...

BACKGROUND Atherosclerosis is an age-related disease. Adiponectin and C1q form a protein complex in human blood, and that serum C1q and C1q-binding adiponectin (C1q-APN) concentrations can be measured. We investigated circulating C1q and C1q-APN levels in Japanese men including elderly men. FINDINGS The study subjects were 509 Japanese men including elderly men. Serum levels of total adiponec...

BACKGROUND Patients on maintenance hemodialysis (HD) have much higher levels of adiponectin (Total-APN). Adiponectin and C1q form a protein complex in human blood, and serum C1q-binding adiponectin (C1q-APN) can be measured. We recently reported that C1q-APN/Total-APN ratio rather than Total-APN correlated with atherosclerosis in diabetics. However, the characteristics of C1q-APN in HD patients...

Anti-C1q autoantibodies are present in sera of patients with several autoimmune diseases, including systemic lupus erythematosus (SLE). Strikingly, in SLE the presence of anti-C1q is associated with the occurrence of nephritis. We have generated mouse anti-mouse C1q mAb's and used murine models to investigate whether anti-C1q autoantibodies actually contribute to renal pathology in glomerular i...

*Corresponding author: Pavan Malleshappa, Division of Nephrology, Department of Medicine, Adichunchanagiri Institute of Medical Sciences, B. G. nagara, Nagamangala Taluk, Mandya District, Karnataka State, India. E-mail: [email protected] C nephropathy refers to a disorder in which C1q deposits are seen in mesangium on immunofluorescence microscopy and mesangial electron dense deposits on el...