Increased frequency of the long (S) allotype of CR1 (the C3b/C4b receptor, CD35) in patients with systemic lupus erythematosus.
The allotypic forms of the C3b/C4b receptor (CR1, CD35) differ in length, in the number of expressed C3b binding sites and thus in their ability to mediate the processing of circulating C3- and C4-bearing immune complexes. We have used a combination of three informative restriction fragment length polymorphisms (RFLPs) to assess the frequencies of the F (most frequent allele comprised of four long homologous repeats (LHR)), S (five LHR) and F' (three LHR) alleles of the C3b/C4b receptor (CR1, CD35) in a French population of patients with systemic lupus erythematosus (SLE) (n = 63) and healthy controls (n = 158). A significantly higher frequency of the S phenotype was observed among patients (51%) as compared with controls (26%). The F' allele was found in 2/61 patients and 1/85 healthy controls, indicating the rare occurrence of the short CR1 allele in SLE. This allele is also extremely rare in the normal population. The overrepresentation of the S long allele among patients is indicative of a genetic linkage between CR1 and susceptibility to SLE.
Laboratoire d'Immunologie, CHU R. Debré, Reims, France.
P
P
Cornillet
P
P
Gredy
J L
JL
Pennaforte
O
O
Meyer
M D
MD
Kazatchkine
J H
JH
Cohen
D015139:Blotting, Southern; D004247:DNA / Q000032:analysis; D005602:France; D005787:Gene Frequency; D006801:Humans; D007519:Isoantigens / Q000378:metabolism; D008180:Lupus Erythematosus, Systemic / Q000235:genetics / Q000378:metabolism*; D012150:Polymorphism, Restriction Fragment Length; D011951:Receptors, Complement / Q000096:biosynthesis* / Q000235:genetics; D017463:Receptors, Complement 3b; D044465:White People
D007519:Isoantigens; D011951:Receptors, Complement; D017463:Receptors, Complement 3b; D004247:DNA