Indices of Disease Activity in Psoriatic Arthritis

The spectrum of psoriatic arthritis in a South African cohort

The aim of this study was to describe the clinical features of patients with psoriatic arthritis (PsA) in a South African cohort. This is a retrospective analysis of patients contributing to development of the international classification criteria for PsA, ClASsification criteria for Psoriatic ARthritis (CASPAR). Patients were all seen at the arthritis clinics at Groote Schuur Hospital, Cape Town. Demographic, clinical, laboratory and radiographic information was collected. This study describes the relevant findings relating to the clinical profile of the patients seen at our centre as well as the effect of family history and/or dactylitis in determining the severity of psoriatic arthritis. There were 45 patients with a male to female ratio of 1:1.25. The mean age of psoriasis onset was 38.34 years (SD 15.54), whilst that of arthritis onset was 43.86 years (SD 13.4). Polyarthritis was the commonest pattern and sacro-iliitis was uncommon. Dactylitis was present in 26%. The presence of family history or of dactylitis did not predict more severe disease. There was a significant correlation between tender and swollen joints. The mean Health Assessment Questionnaire (HAQ) score was 1.05. Eighty-three percent showed evidence of radiological changes, and distal interphalangeal (DIP) erosions were found in 54%. Arthritis mutilans was present in 31%. There were no black subjects in the cohort. The clinical patterns of PsA in our cohort are similar to those reported elsewhere. The paucity of blacks amongst this cohort requires further study. PsA-specific measures of disease activity need to be developed. PsA causes significant joint damage and disability.

Beneficial effect of n-3 polyunsaturated fatty acids on inflammation and analgesic use in psoriatic arthritis: a randomized, double blind, placebo-controlled trial

OBJECTIVE

This study aimed to investigate the effects of marine n-3 polyunsaturated fatty acids (PUFAs) on disease activity, use of analgesics, and inflammatory biomarkers in patients with psoriatic arthritis (PsA).

METHOD

Patients with established PsA (n = 145) were investigated in a randomized, double-blind, placebo-controlled study. The participants received a supplement of 3 g n-3 PUFA/day or 3 g olive oil/day (control) for 24 weeks. Outcome measures for disease activity, use of analgesics, and leukotriene formation from activated granulocytes were assessed at baseline and at study end.

RESULTS

In total, 145 patients were included and 133 completed the study. After 24 weeks, the n-3 PUFA group showed a decrease in Disease Activity Score (DAS28-CRP), 68 tender joint count, enthesitis score, and psoriasis area and severity index, although not significantly different from the controls. There was a significant reduction in non-steroidal anti-inflammatory drug (NSAID) and paracetamol use compared with controls (p = 0.04). In addition, the participants in the n-3 PUFA group had significantly lower formation of leukotriene B₄ (p = 0.004) from stimulated granulocytes and significantly higher formation of leukotriene B₅ (p < 0.001) compared with controls.

CONCLUSION

The n-3 PUFA-supplemented group showed improvement in outcome measures for disease activity, although the difference between the groups was not statistically significant. However, use of NSAIDs and paracetamol was significantly reduced in the n-3 PUFA group compared to the control group. Finally, there was a significant decrease in leukotriene B₄ formation in the n-3 PUFA group compared with controls.

The effect of marine n-3 polyunsaturated fatty acids on cardiac autonomic and hemodynamic function in patients with psoriatic arthritis: a randomised, double-blind, placebo-controlled trial

BACKGROUND

The aim of this study was to investigate the effect of marine n-3 polyunsaturated fatty acids (PUFA) on cardiac autonomic function and vascular function in patients with psoriatic arthritis.

METHODS

The study was conducted as a randomized, double-blind, placebo-controlled trial, where 145 patients with psoriatic arthritis were supplemented with 3 g of n-3 PUFA or olive oil (control) daily for 24 weeks. Blood pressure, heart rate, heart rate variability (HRV), central blood pressure, pulse wave velocity (PWV) and fatty acid composition of granulocytes, were determined at baseline and after supplementation.

RESULTS

At baseline we found a significant difference in the mean of all normal RR intervals (inverse of heart rate, vary from beat to beat) when comparing subjects with the highest vs the lowest fish intake (p = 0.03). After supplementation for 24 weeks there was a trend towards an increase in RR (p = 0.13) and decrease in heart rate (p = 0.12) comparing the n-3 PUFA group with the control group. However, per-protocol analysis showed significantly increased RR (p = 0.01) and lowered heart rate (p = 0.01) in the n-3 PUFA supplemented patients compared with controls. Blood pressure, PWV and Central blood pressure did not change after supplementation with n-3 PUFA. Adjustment for disease activity and conventional cardiovascular risk factors did not change the results.

CONCLUSIONS

Marine n-3 PUFA increased RR intervals in patients with psoriatic arthritis which may suggest a protective effect of n-3 PUFA against cardiovascular disease in this population.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT01818804.

Measuring joint involvement in polyarticular psoriatic arthritis: an introduction of alternatives

OBJECTIVE

To compare the reliability of 3 different simplified joint counts with the gold standard 66 swollen/68 tender joint count (JC66/68) for assessing clinical response in patients with polyarticular psoriatic arthritis (PsA).

METHODS

The 28-joint count (JC28), in the same way that it is used in rheumatoid arthritis, and 2 measures including distal interphalangeal (DIP) joints (the 32-joint count [JC32], including all finger joints as well as wrists and knees, and 36-joint count [JC36], which additionally included elbows and ankles), were compared with the JC66/68 in 182 patients using data from the Infliximab Multinational Psoriatic Arthritis Controlled Trial 2 trial database. Pearson's correlation coefficients were calculated to compare the swollen and tender JC28, JC32, and JC36 with the corresponding results of the total JC66/68. American College of Rheumatology (ACR) responses based on the individual measures were compared, and their ability in predicting a clinical response of ACR 20% improvement (ACR20) based on the JC66/68 was assessed by calculating the area under the receiver operating characteristic curve via logistic regression and the maximum Youden indices at weeks 14 and 24.

RESULTS

All simplified joint counts were highly correlated to the standard JC66/68 both for tenderness and swelling at each individual visit (Pearson's correlation coefficients consistently >0.8, n = 182-200; P < 0.0001). Logistic regression for ACR20 response showed that area under the curve was constantly >0.91, with comparable results for Youden indices of the simplified joint counts.

CONCLUSION

All simplified joint counts considered seemed sufficiently sensitive and specific to measure clinical response in trial patients with polyarticular PsA when compared with the JC66/68, no matter whether DIP joints were included (the JC36 and JC32) or excluded (the JC28). Further research will be needed to clarify this issue.

The Definition and Measurement of Disease Modification in Inflammatory Rheumatic Diseases

This article focuses on measures that are used to evaluate disease activity, damage, and function in three major inflammatory musculoskeletal disorders. The instruments used in rheumatoid arthritis, where most of the methodologic work has been done, are extensively discussed and instruments for the respective domains in psoriatic arthritis and ankylosing spondylitis are likewise presented.

Outcome measures in psoriatic arthritis clinical trials

Outcome measures in psoriatic arthritis (PsA) have been primarily borrowed from the assessment of rheumatoid arthritis and ankylosing spondylitis, although several specific measures for PsA have been established. The advent of new therapeutic agents for the treatment of PsA has made the need for specific outcome measures for PsA more critical to evaluate the heterogeneous manifestations of this disease and features that are unique to its assessment. Several outcome measures have been validated for use in PsA clinical trials while others are being evaluated by groups such as The Group for Assessment of Psoriasis and Psoriatic Arthritis for future use in clinical trials.

Psoriatic arthritis

Despite the fact that psoriatic arthritis has been recognized as an entity for almost five decades, there are still no valid criteria for either its diagnosis or classification. Several sets of criteria have been proposed but none was studied. None the less, investigators have been able to study the condition and describe its unique features and its natural course and prognosis. However, in order to facilitate further studies, it would be worthwhile to develop an internationally accepted and validated set of criteria, both for the diagnosis and classification of the disease, as well as for the assessment of damage. These criteria would help set up appropriate therapeutic trials in this condition as well.

Second-line treatment in seronegative spondylarthropathies

The literature concerning second-line treatment of seronegative spondylarethropathies from 1940 to August 1993 was reviewed. Sulfasalazine appeared to be effective in the treatment of ankylosing spondylitis (AS) and promising in reactive arthritis (ReA) and Reiters' syndrome (RS). Methotrexate and azathioprine were associated with a remarkable improvement in some cases of AS and RS. Methylprednisolone and levamisole were both efficacious in AS, but levamisole was associated with occasional severe side effects. Radiation therapy led to short-term improvement in AS, but was abandoned because of severe long-term side effects. Only sulfasalazine has been studied in sufficient detail to allow definitive conclusions, but methotrexate and azathioprine may be promising drugs.

Laboratory findings and pathology of psoriatic arthritis

Over recent years there has been a great deal of interest in the immunology, molecular biology and pathology of psoriasis and PsA. The pathogenetic mechanisms in PsA are less well understood than those described for psoriasis. There are almost certainly genetic and immune components. What is not clear is whether there is a primary immune defect or whether unknown stimuli lead to the recruitment of the immune system and establishment of the disease; nor is it absolutely clear whether PsA is an extension of psoriasis in certain prone individuals. Vascular abnormalities are the earliest histopathological changes to occur in the psoriatic plaque and are also prominent in the psoriatic synovium. Espinoza et al (1982) have suggested there may be a primary vascular defect in PsA. The fact that vascular changes occur before infiltration of immunocompetent cells and are the first changes to resolve with treatment of psoriasis is likely to be significant. Abnormalities in the cellular kinetics and growth factor sensitivity of keratinocytes, fibroblasts and synoviocytes have been highlighted previously. The ability of these cells to produce growth factors and express HLA class II antigens demonstrates the potential for them to initiate and maintain inflammation. The development and possible increased incidence of PsA in patients with such profound immunodeficiency as acquired immune deficiency syndrome suggests that T helper cells do not play a significant role in the establishment of the disease (Arnett et al, 1991). Previously, many immune changes were described. Unfortunately they are non-specific and do not indicate a fundamental defect or marker of PsA. Vasey (1985) has suggested that insidious exposure to Gram-positive bacteria from the gut, tonsils and psoriatic plaques results in chronically stimulated monocytes, macrophages and dendritic cells. These cells are able to migrate throughout the body. Repeated microtrauma may result in the homing of these cells to sites of injury in the skin, synovium and tendons. Interaction with genetically hyperactive synoviocytes and keratinocytes with concomitant release of growth factors may precipitate early lesions of psoriasis and PsA. This hypothesis needs to be substantiated, but it ties together some of the varying observations seen. Many abnormal laboratory findings have been described. Unfortunately, none of the serological changes is sufficiently specific to be of great help in diagnosis. CRP levels and the ESR remain the best promise as markers of the inflammatory component of the arthritis, while other indicators correlate with certain facets of the disease pathology, but as yet have not found a true niche in the management of PsA.(ABSTRACT TRUNCATED AT 400 WORDS)

Treatment of psoriatic arthritis by extracorporeal photochemotherapy

Five patients with long-standing seronegative arthritis resistant to conventional therapy and who also had psoriasis of the skin were treated with photopheresis. This mode of treatment combines a lymphocyte-enrichment procedure with 8-methoxypsoralen-photochemotherapy. There was a marked in vitro effect on treated lymphocytes, with a reduction of viability, proliferation and mitogen response. There was a slight to moderate clinical improvement in four of the five patients with regard to the strength of grip, swelling, pain, morning stiffness, the dosage of non-steroidal anti-rheumatic drugs and the radiographical changes. The skin lesions did not respond to photopheresis. Short-term side-effects were minimal and consisted of a temporary sensitivity of the eyes to light and signs of circulatory dysregulation immediately after treatment. This experimental therapy has some measurable but not dramatic effect in improving psoriatic arthropathy.