Psoriatic arthritis: clinical patterns, rheumatoid factor, anti-cyclic citrullinated peptide and human leukocyte antigen risk alleles

Psoriatic arthritis is an inflammatory arthritis associated with psoriasis.Both rheumatoid factor and anti-cyclic citrullinated peptide antibodies positive psoriatic arthritis patients may be in risk for development of symmetrical polyarthritis pattern.Symmetrical polyarthritis pattern was predominant(42%)among clinical pattern of psoriatic arthritis.Among 10 rheumatoid factor positive patients,8(80%)patients had symmetrical polyarthritis pattern and out of 7 anti-cyclic citrullinated peptide antibody positive patients,7(100%)patients had symmetrical polyarthritis pattern.Association of anti-cyclic citrullinated peptide(P=0.008)and rheumatoid factor(P=0.006)showed statistical significance with symmetrical polyarthritis pattern.Human leukocyte antigen-B*07,*38 and human leukocyte antigen-C*07 were predominantly found in rheumatoid factor and anti-cyclic citrullinated peptide positive psoriatic arthritis patients.Background:Psoriatic arthritis is an inflammatory arthritis associated with psoriasis.It is usually seronegative in nature but a small percentage of patients may be positive for rheumatoid factor and anti-cyclic citrullinated peptide antibodies.Anti-cyclic citrullinated peptide and rheumatoid factor are highly specific for rheumatoid arthritis but their role is not clear in psoriatic arthritis.The prevalence and prognostic value of anti-cyclic citrullinated peptide antibody and rheumatoid factor in psoriatic arthritis patients is not well known.The aim of this study was therefore to investigate the prevalence of anti-cyclic citrullinated peptide antibodies and rheumatoid factor in psoriatic arthritis patients and assess their clinical associations and also to see the distribution of human leukocyte antigen-B and human leukocyte antigen-C locus antigens in anti-cyclic citrullinated peptide antibody and rheumatoid factor positive psoriatic arthritis patients.Methods:Fifty patients with psoriatic arthritis were tested for the presence of rheumatoid factor and anti-cyclic citrullinated peptide antibodies.Polymerase chain reaction was done with sequence specific primer for detection of human leukocyte antigen-B and human leukocyte antigen-C locus antigens in rheumatoid factor and anti-cyclic citrullinated peptide positive psoriatic arthritis patients.Data on five clinical patterns of rheumatological manifestations of psoriatic arthritis patients were collected prospectively on all patients and statistically compared between anti-cyclic citrullinated peptide,rheumatoid factor positive and negative patients by chi-square test.We also see the distribution of human leukocyte antigen-B and human leukocyte antigen-C locus antigens in anti-cyclic citrullinated peptide antibody and rheumatoid factor positive psoriatic arthritis patients.Results:Among 50 psoriatic arthritis patients,rheumatoid arthritis test was positive in 10(20%)patients and anti-cyclic citrullinated peptide was positive in 7(14%)patients.Symmetrical polyarthritis pattern is predominant among clinical pattern of psoriatic arthritis which was found in 21(42%)patients.Among 7 anti-cyclic citrullinated peptide positive psoriatic arthritis patients,symmetrical polyarthritis pattern is predominant and it was found in 7(100%)patients.Among 10 rheumatoid factor positive psoriatic arthritis patients,symmetrical polyarthritis pattern is predominant and it was found in 8(80%)patients.In this study,symmetrical polyarthritis pattern is statistically associated with anti-cyclic citrullinated peptide positive psoriatic arthritis patients(P=0.008)and rheumatoid factor positive psoriatic arthritis patients(P=0.006).Human leukocyte antigen-B*07,*38 and human leukocyte antigen-C*07 were predominantly found in rheumatoid factor and anti-cyclic citrullinated peptide positive psoriatic arthritis patients.Conclusion:Both rheumatoid factor and anti-cyclic citrullinated peptide positive psoriatic arthritis patients may be in risk for development of symmetrical polyarthritis pattern.Among rheumatoid factor and anti-cyclic citrullinated peptide positive psoriatic arthritis patients,Human leukocyte antigen-B*07,*38 and human leukocyte antigen-C*07 alleles were more frequently found alleles.

Macrophage-inducible C-type lectin is associated with anti-cyclic citrullinated peptide antibodies-positive rheumatoid arthritis in men

Background Macrophage-inducible C-type lectin （MINCLE） is an important member of C-type lectin superfamily, which has been shown evidence for susceptibility to arthritis in animal models. We aimed to investigate the possible association of MINCLE with rheumatoid arthritis （RA） susceptibility in Chinese Han population. Methods Haplotypes from HapMap database （Chinese Han Beijing, CHB） were used to select tag-single nucleotide polymorphism （SNP） （r2=0.8） residing in MINCLE gene. A total of 563 patients with RA and 404 healthy controls were TagMan genotyped for SNP rs10841845. Association analyses were performed on the whole data set and on RA subsets based on gender difference and the status of anti-cyclic citrullinated peptide （anti-CCP） antibody in RA patients. Association statistics were calculated by age and sex adjusted logistic regression. Results Overall, MINCLE SNP rs10841845 was not associated with susceptibility to RA. However, following anti-CCP stratification, rs10841845 GG genotypes conferred a significantly protective effects against anti-CCP-positive RA （OR 0.65, 95% CI 0.430-0.995, P=0.048）. Following gender stratification, SNP rs10841845 G allele appeared to insert its RA protective effect only in male patients, both at allele level （G vs. A OR 0.66, 95% CI 0.46-0.93, P=0.018） and at genotype level （GG vs. AA±AG, OR 0.429, 95% CI 0.20-0.95, P=0.036）. Notably, the male RA protective effect of rs10841845 G allele was only seen in anti-CCP-positive RA （G vs. A： OR 0.64, 95% CI 0.43-0.96, P=0.029; GG vs. AA＋AG： OR 0.375, 95% CI 0.14-0.94, P=0.038）. Furthermore, we observed a significant reduction of Disease Activity Score （DAS） 28 score （3.91±0.70 vs. 5.66±0.31, P=-0.022） and serum C-reactive protein levels （31.64±24.13 vs. 91.80±12.02, P=0.012） in male anti-CCP-positive RA patients carrying rs10841845 GG genotype, compared with patients carrying AA±AG genotypes. Conclusions Our study provides the evidence for a gender specific association between MINCLE rs10841845 and RA susceptibility. The SNP rs10841845 G allele appears to have protective effect against anti-CCP-positive RA and confer reduced RA activity in men.

Challenges of Rheumatoid Arthritis Management in Sub-Saharan Africa in the 21st Century

In recent decades, several advances have been made in the management of rheumatoid arthritis (RA) both in the diagnostic field and in the therapeutic field. Unfortunately, RA remains poorly studied in black Africa. Epidemiological data are rare and controversial. The estimated prevalence of RA in Africa is about 0% - 2.54%. Risk factors associated with RA must be studied by taking into account special features of black Africa such as the low tobacco consumption in certain regions, the tropical climate and the high frequency of endemic parasitic and viral infections. The initially supposed mildness of RA in black Africa is increasingly challenged. The diagnosis is often made too late because of the scarcity of rheumatologists and ignorance. Diagnostic tools are limited to the clinical data, the erythrocyte sedimentation rate and radiographs as the other tools are poorly available. In addition, there are misconceptions in African communities, responsible for loss of sight during follow-up and treatment discontinuations. This is exacerbated by the shortage of disease-modifying anti-rheumatic drugs (DMARDs) and the inability to afford them. Furthermore, biological agents are very difficult to access. Further studies are essential to better understand the characteristics of RA in black Africa. Thus, collaborations between African and Western research teams seem very important. In order to make available the DMARDs especially biological agents, pharmaceutical companies can contribute through research partnerships. Moreover, governments should provide a better place for chronic inflammatory diseases in the programs against non-communicable diseases. Finally, training must also be promoted to increase the number of specialists and the level of knowledge of other health workers.

Increased IgG Rheumatoid Factor-Positivity in the Asian Rheumatoid Arthritis Patients Irrespective of Ethnicity

Aim of Work: Initial observations implied IgG rheumatoid factor (RF) to be common among Malaysian rheumatoid arthritis (RA) patients. We tested this hypothesis and used a multiethnic RA cohort (Malays, Chinese and Indians) to investigate whether the IgG RF predominance might be genetically or environmentally determined. Patients and Methods: 556 serum samples comprising 171 patients classified as RA according to the 1987 ACR criteria, 60 patients with other rheumatic diseases and 325 non-rheumatic controls were tested for IgG RF, IgM RF and anti-CCP by ELISA. The findings were then tested in a larger RA case-control cohort (n = 1844). Results: IgG RF predominated over IgM RF in all the investigated ethnic groups. The sensitivity, specificity, and diagnostic accuracy of IgG RF (55.6%, 91.2% and 80.2%, respectively) were superior compared to IgM RF, but comparable to anti-CCP. IgG RF was however, also increased in the Malaysian controls, but the IgG RF superiority over IgM RF was still apparent after cutoff adjustment according to the 1987 ACR criteria. Autoantibody levels did not differ between the three ethnic groups. The Receiver Operating Characteristics (ROC) curves showed larger areas under the curves for IgG RF (0.826) and for anti-CCP (0.867) than for IgM RF (0.737). Review of the literature showed consistently higher sensitivity for IgG RF in studies of Asian RA patients as compared to Caucasian and African-American studies. Conclusion: Increased frequency of IgG RF-positive in RA populations with different genetic background living in Malaysia argues for an environmental factor selectively amplifying the IgG RF response.