Frequency Of Rheumatoid Factor Research Articles

Little change in mutational pattern and frequency of rheumatoid factor (RF) isolated before and after immunization with tetanus toxoid (TT)

Little change in mutational pattern and frequency of rheumatoid factor (RF) isolated before and after immunization with tetanus toxoid (TT)

Little change in mutational pattern and frequency of rheumatoid factor (RF) isolated before and after immunization with tetanus toxoid (TT)

Little change in mutational pattern and frequency of rheumatoid factor (RF) isolated before and after immunization with tetanus toxoid (TT)

IgM and IgA rheumatoid factors in canine polyarthritis

IgM and IgA rheumatoid factor (RF) were detected by ELISA using a purified dog IgG as antigen in normal controls ( N = 84), dogs with unclassified polyarthritis ( N = 95), dogs with rheumatoid arthritis (RA) ( N = 22), dogs with systemic lupus erythematosus (SLE) ( N = 35), dogs with leishmaniasis or heart worm disease ( N = 20) and dogs with pyometra ( N = 16). Frequency and titre of IgM and IgA RF are low and comparable ( P < 0.05) in dogs with unclassified polyarthritis or RA: respectively 24.2% and 27.3% for IgM RF and 21.0% and 18.2% for IgA RF; the mean titre being respectively 0.781 ± 0.581 and 0.649 ± 0.365 for IgM RF, and 0.774 ± 1.331 and 0.740 ± 1.169 for IgA RF. The frequencies of IgM and IgA RF are a little higher in dogs with SLE (IgM RF: 37.1%, IgA RF: 25.7%) and higher in dogs with leishmaniasis or heart worm disease (45.0% and 30.0%), especially in dogs with pyometra (68.7% and 37.5%). So, although dogs can produce IgM and IgA RF, these auto-antibodies are uncommon in dogs with RA. Furthermore, when RF are present their titre is much lower than in human RA.

Occurrence of a rheumatoid factor cross-reactive kappa light-chain idiotope in rheumatoid arthritis families

The occurrence of IgM rheumatoid factor (RF) and RF-associated kappa-III light-chain idiotope identified by monoclonal antibody 6B6.6 in the serum from 22 patients with rheumatoid arthritis (RA) and 68 relatives without connective tissue diseases in 15 families was determined by solid-phase enzyme-linked immunosorbent assays. Serum IgM RF was present in 19 RA patients from 12 families and 12 arthritis-free relatives of 4 families. It was not found in any of 9 spouses included in the study or in 44 of 45 unrelated healthy adult controls. RF-associated 6B6.6 idiotope was detected in 42% of the IgM RF(+) RA patients and in 50% of the IgM RF(+) arthritis-free relative, but not in the adult controls, spouses, and IgM RF(-) RA patients and relatives. It was present in one RA serum from each of 8 families and 6 sera from arthritis-free relatives of 2 families (5 of whom were from one family). Where present, the idiotope-positive RF represented only a small fraction of the serum IgM RF of the RA patients (0.1-2.1%) and relatives (1.5-14%). The increased frequency of IgM RF(+) individuals, with and without RA, in family groups suggests a genetic predisposition for expression of RF. The small proportion of RF bearing the 6B6.6 idiotope in both RA patients and unaffected family members supports the view that the number of germline genes encoding for RF is large or that extensive mutation occurs in the course of RF expression, whether idiopathic or associated with RA. In addition, nonuniform expression of the idiotope in RF within family groups indicates that the various clones of RF producing cells are to a large extent independently regulated.

IgM rheumatoid factor (RF), IgA RF, IgE RF, and IgG RF detected by ELISA in rheumatoid arthritis.

One hundred patients with rheumatoid arthritis (RA), of whom 73 were seropositive by latex or Waaler-Rose (WR) assays, or both, 100 healthy subjects, and 102 diseased controls (22 patients with systemic lupus erythematosus (SLE) and 80 with bronchial asthma) were evaluated for the presence of IgM rheumatoid factor (RF), IgA RF, IgE RF, and IgG RF by an enzyme linked immunosorbent assay (ELISA). Ninety two per cent, 65%, 68%, and 66% of the patients with RA were found to be positive for IgM, IgA, IgE, and IgG respectively. A positive correlation existed between the levels of IgM RF and IgA RF on the one hand and disease activity on the other, and the levels of IgM RF and IgA RF correlated with the levels of circulating immune complexes as measured by a C1q binding assay. The presence of extra-articular features also correlated positively with the levels of IgA RF and IgE RF. Five out of six patients with Sjögren's syndrome had very high levels of IgA RF. Of 47 patients typed for HLA-DR, DR1 and DR2 were significantly more frequent in those with the highest levels of IgM RF. Conversely, DR3 was associated with low levels or absence of IgA RF and IgE RF. These results suggest that immune response genes may regulate the level of different RF isotypes. The frequencies of IgM, IgA, IgE, and IgG RF were 59%, 36%, 9%, and 27% respectively in SLE and 25%, 2.5%, 70%, and 59% in bronchial asthma.

Lack of association of rheumatoid factor with either circulating immune complexes or tumor burden in cancer patients.

The frequency of rheumatoid factor (RF) seropositivity and the frequency of association of RF with immune complex (IC) elevation were determined in 72 patients with a variety of solid tumors, in 78 patients with IC-associated diseases, 27 patients with non-IC-associated diseases, and in 31 normal healthy controls. The frequency of RF positivity in cancer patients (31%) was virtually identical to that in patients with IC-associated diseases (28%), and did not differ significantly from that seen in patients with non-IC-associated disease (15%). Whereas IC elevation was clearly related to tumor progress, RF was not. RF and IC status also appeared to be unrelated to each other, not only in cancer patients, but in patients with other diseases as well. The results do not support the concept that RF reflects progressive tumor growth or an immune response to IgG-containing immune complexes.

Lack of association of rheumatoid factor with either circulating immune complexes or tumor burden in cancer patients

The frequency of rheumatoid factor (RF) seropositivity and the frequency of association of RF with immune complex (IC) elevation were determined in 72 patients with a variety of solid tumors, in 78 patients with IC-associated diseases, 27 patients with non-IC-associated diseases, and in 31 normal healthy controls. The frequency of RF positivity in cancer patients (31%) was virtually identical to that in patients with IC-associated diseases (28%), and did not differ significantly from that seen in patients with non-IC-associated disease (15%). Whereas IC elevation was clearly related to tumor progress, RF was not. RF and IC status also appeared to be unrelated to each other, not only in cancer patients, but in patients with other diseases as well. The results do not support the concept that RF reflects progressive tumor growth or an immune response to IgG-containing immune complexes.

Serological and immunohistological studies on lepromatous leprosy.

Sera of patients with lepromatous leprosy were studied for the presence of a variety of antibodies and immune complexes (IC). The frequencies of heterophile, Hanganutziu-Deicher and Forssman antibodies were 61 and 43%, respectively, which were significantly higher than those in other diseases. The frequency of antibodies to cardiolipin was 89% and the frequency of rheumatoid factor was 34%. Circulating IC were demonstrated in 54% of the patients' sera by Raji-cell test and in 43% by anti-antibody inhibition test. Analyses of immunoglobulin classes of IC revealed that IgG was predominant in IC of patients with lepra reaction (LR) and IgM in patients without LR. Immune deposits were found in and between cells of dermis in skin biopsy specimens of patients with LR.