title: Complement C4 null alleles as a marker of gold or D-penicillamine toxicity in the treatment of rheumatoid arthritis.
abstract: C4 null alleles and HLA-DR antigens were defined in 48 rheumatoid arthritis (RA) subjects who had developed renal or heamatological side effects to gold or penicillamine, as compared to 33 RA subjects who had received the drugs for similar time periods without developing side effects. A C4A null allele was found in 56% of subjects with and 31% of those without side effects (P = 0.027, relative risk 2.8). A similar but statistically non-significant trend was observed with the C4B null allele (P = 0.64) resulting in a higher risk of drug toxicity in rheumatoid patients bearing either a C4A or C4B null allele (relative risk 5.7). Frequencies of DR3 and DR4 were similar in the two groups.
authors.affiliation: University of Manchester, Rheumatic Diseases Centre, Hope Hospital, Salford.
authors.forename: R W
authors.initials: RW
authors.lastname: Clarkson
authors.forename: P A
authors.initials: PA
authors.lastname: Sanders
authors.forename: D M
authors.initials: DM
authors.lastname: Grennan
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000235:genetics / Q000276:immunology; D003181:Complement C4 / Q000235:genetics*; D005787:Gene Frequency; D005819:Genetic Markers; D006046:Gold / Q000009:adverse effects* / Q000627:therapeutic use; D015803:HLA-DR3 Antigen / Q000032:analysis; D006801:Humans; D008969:Molecular Sequence Data; D010396:Penicillamine / Q000009:adverse effects* / Q000627:therapeutic use
chemical_list: D003181:Complement C4; D005819:Genetic Markers; D015803:HLA-DR3 Antigen; D006046:Gold; D010396:Penicillamine