Reduced erythrocyte complement receptor type 1 in systemic lupus erythematosus is related to a disease activity index and not to the presence or severity of renal disease

Abstract

The present study investigated the expression of the complement receptor type 1 (CR1) on the membrane of erythrocytes (CR1/E) of patients with systemic lupus erythematosus (SLE) by flow cytometry. We found a significant reduction in CR1/E numbers in SLE patients (n = 52), compared to controls (512 +/- 171 and 689 +/- 146, respectively, P = 0.0001). Reduction was more pronounced in active disease patients. The mean CR1/E number observed in patients with inactive disease was 546 +/- 163 CR1/E, while active SLE patients presented a mean of 385 +/- 133 CR1/E (P = 0.001). Patients with SLE with similar activity indexes tend to have similar CR1/E numbers, irrespective of disease severity. We also observed a trend to CR1/E reduction in severe nephritis patients. A small group of SLE patients with chronic renal failure and inactive disease showed CR1/E numbers nearly identical to controls (689 +/- 146 versus 686 +/- 123, respectively, P = 0.95). This was the only group of SLE patients with normal CR1/E numbers. These results confirm the CR1/E reduction in SLE patients as previously described, and also suggest that this reduction is related to disease activity and not to disease severity.

CR1 on erythrocytes of Brazilian systemic lupus erythematosus patients: The influence of disease activity on expression and ability of this receptor to bind immune complexes opsonized with complement from normal human serum

“…These results confirm the CR1/E reduction in SLE as previously described [7,15,27] and suggest a similar behaviour of pathophysiology independent of a specific ethnicity of the SLE patient population.…”

“…The low number of CR1/E in SLE patients appears to be due to acquired factors related to disease activity [14,15]. However, inheritance and enhanced proteolytic cleavage of cell surface CR1 are two putative mechanisms to explain this phenomenon [7,16e18].…”

Low-dose Radiation Induces Antitumor Effects and Erythrocyte System Hormesis

“…The erythrocyte immune function can be determined with only a small sample of blood, so it's clinically easy and useful and can substitute lymphocyte immune function examination.Red blood cells could also produce NKEF (Natural Kill Cell Enhancement Factor), enhanced the function of natural killer (NK) cells and the lethal effect on tumor. Erythrocyte immune function in tumor patients was lower than normal people, so it was perhaps linked to tumor occurrence (de Carvalho Lins et al, 2004). The effect of low dose radiation on erythrocyte immune function has not been reported.…”

Complement Receptor 1 and 2 Deficiency Increases Coxsackievirus B3-Induced Myocarditis, Dilated Cardiomyopathy, and Heart Failure by Increasing Macrophages, IL-1β, and Immune Complex Deposition in the Heart

“…CR1 levels are significantly lower in SLE patients, and genetically susceptible CR1/2-deficient mice develop increased lupus-like disease (5,9,10,54). Molecular genetics studies and analysis of twin pairs discordant for the presence of SLE suggest that reduced levels of CR1 are an acquired phenomenon (55,56). Thus, it is possible that viral or bacterial infections could reduce CR1 expression resulting in increased autoimmune disease in susceptible individuals.…”