The Cooperative Studies Program, Department of Veterans Affairs Office of Research and Development, Canadian Institutes for Health Research, and an interagency agreement with the National Institutes of Health-American Recovery and Reinvestment Act.

Isoelectric focusing analyses of sera from patients with rheumatoid arthritis (RA) demonstrate two populations of antibodies directed aanst the Fab portion of pooled human IgG. One population is composed of polyclonal akline anti-Fab antibodies (aFABA) and the other, acidic aFABA which are more clonally restricted. In this study we have identified the immunoglobulin classes and subclasses of these antibodies in RA sera.

Objective. To compare the health-related quality of life (HRQOL) and the functional ability by race in patients with gout.Methods. In a 9-month prospective cohort multicentre study, patients with gout self-reported race, dichotomized as Caucasian or African American (others excluded). We calculated HRQOL/function scores adjusted for age, study site and college education for Short Form-36 (SF-36; generic HRQOL), Gout Impact Scale (GIS; disease-specific HRQOL) and HAQ-disability index (HAQ-DI; functional ability). Longitudinally adjusted scores were computed using multivariable mixed-effect regression models with a random patient effect and fixed sequential visit effect (3-monthly visits).Results. Compared with Caucasians (n = 107), African Americans (n = 60) with gout were younger (61.1 vs 67.3 years) and had higher median baseline serum urate (9.0 vs 7.9 mg/dl) (P < 0.01). African Americans with gout had worse HRQOL scores on three SF-36 domains, the mental component summary (MCS) and two of the five GIS scales than Caucasians [mean (S.E.); P 4 0.02 for all]: SF-36 mental health, 39.7 (1.1) vs 45.2 (0.9); SF-36 role emotional, 42.1 (4.2) vs 51.4 (4.2); SF-36 social functioning, 36.0 (1.1) vs 40.0 (0.9) (P = 0.04); SF-36 MCS, 43.2 (3.1) vs 50.0 (3.2); GIS unmet treatment need, 37.6 (1.6) vs 31.5 (1.4); and GIS concern during attacks, 53.3 (3.7) vs 47.4 (3.7). Differences between the respective HAQ-DI total scores were not statistically significant; 0.98 (0.1) vs 0.80 (1.0) (P = 0.11). Racial differences in SF-36 mental health, role emotional and MCS scales exceeded, and for HAQ-DI approached, the minimal clinically important difference thresholds.Conclusions. African Americans with gout have significantly worse HRQOL compared with Caucasians. Further research is necessary in the form of studies targeted at African Americans on how best to improve these outcomes.

SUMMARY Individual preparations of affinity purified anti‐F(ab′)2 antibodies and anti‐Fc antibodies isolated from the sera of patients with rheumatoid arthritis (RA), were examined for reactivity with the Fab and Fc fragments of human IgG. Western blot assays demonstrated specific interaction of affinitypurified anti‐Fab antibodies with both Fab and Fc molecules. Approximately one‐half of the anti‐Fab antibody preparations studied contained IgG antibodies reactive with Fab and Fc fragments in ELISA, suggesting the existence of naturally occurring epibody‐like autoantibodies in these patients. Thirteen of 14 affinity‐purified anti‐Fc antibody preparations contained IgG cross‐reactive with Fab molecules in ELISA. Double‐adsorption assays on affinity columns demonstrated that a minimum of 14%, and possibly as much as 50%, of the IgG anti‐Fab antibodies reacted with the Fc of IgG. Conversely, a minimum of 12%, and possibly as much as 70%, of the IgG anti‐Fc antibodies reacted with IgG Fab molecules. Anti‐Fab antibodies isolated from non‐RA individuals also exhibited anti‐Fc reactivity in ELISA. demonstrating the presence of these dual‐reactive antibodies in other autoimmune and normal individuals. These studies establish the presence of naturally occurring IgG autoantibodies reactive with both the Fab and Fc fragments of human IgG. Their existence emphasizes the potential of anti‐immunoglobulin antibodies to recognize a multiplicity of antigens, possibly including other members of the immunoglobulin supergene family.

Clonally restricted anti-IgG antibodies were detected, by isoelectric focusing (IEF) and chromatofocusing techniques, in the sera of patients with rheumatoid arthritis (RA). Anti-Fab antibodies were predominantly acidic proteins with isoelectric points of 4.5-6.5 and displayed restricted spectrotype patterns. Proteins reactive with the Fc portion of IgG showed polyclonal spectrotype patterns with alkaline PI of 7.5-9.0. A limited array of anti-Fab spectrotypes was consistently detected in RA sera when analyzed by IEF on 6M urea gels. Additional anti-Fab antibody bands were detected when the RA sera were dialyzed against 4-6M urea prior to IEF analysis, indicating that some anti-Fab antibodies exist in a complexed form in serum. Under these dissociating conditions, anti-Fab antibodies could also be detected in normal subjects, but the spectrotype patterns were more restricted than those in RA sera. Because anti-Fab antibodies may regulate normal immune responses, the increased quantity of clonally restricted ,anti-Fab antibodies in RA may indicate an abnormality of this immunoregulation.~~p -