Nail psoriasis: a review

Nail psoriasis is common, occurring in up to half of patients with psoriasis and in 90% of patients with psoriatic arthritis. Left untreated, it may progress to debilitating nail disease, which leads to significant functional impairment. The most common clinical signs of nail psoriasis are nail plate pitting and onycholysis. Other classical signs include oil drop discoloration, subungual hyperkeratosis, and splinter hemorrhages. The modified Nail Psoriasis Severity Index (mNAPSI) can be used to grade the severity of nail psoriasis, while the Nail Psoriasis Quality of Life Scale (NPQ10) is a questionnaire that evaluates the impact of nail psoriasis on the patient's functional status and quality of life. Treatment of nail psoriasis should be individualized according to the patient's preferences, severity of nail changes, and presence of skin and/or joint involvement. Both topical and intralesional therapies are safe and effective treatment modalities for nail disease, but are limited by poor adherence and pain, respectively. Systemic therapy such as oral retinoids may be considered for widespread nail disease causing significant morbidity. Among biologic agents, tumor necrosis factor-α inhibitors and T-cell-targeted therapies such as ustekinumab may be useful for refractory severe nail psoriasis.

A multicentre study on high-frequency ultrasound evaluation of the skin and joints in patients with psoriatic arthritis treated with infliximab

OBJECTIVES

Our objective was to describe the ultrasound features of patients with PsA in joints and skin and their changes after treatment with infliximab.

METHODS

Eight hospitals recruited PsA active patients. Clinical (joint count for pain, TJC, and swelling, SJC, pain VAS, ESR, C-reactive protein and PASI) and US variables (plaque thickness, PD signal of dermal lesions, synovitis, erosions, and PD signal, assessed by 4-category ordinal scales) were independently recorded at baseline and 4, 12 and 24-week after starting treatment with infliximab. The results were analysed with paired T, Wilcoxon test, ANOVA and marginal homogeneity test.

RESULTS

Changes in 24 patients from baseline to last available data were significant for clinical variables, pain VAS, TJC and SJC as well as for ESR, CRP (all p<0.0005). Dermatological PASI changed from 14.6±14.9 to 2.1±4.1 and plaque thickness from 3.34±1.75 mm to 1.74±0.96 mm (both p<0.0005); synovitis and PD signal improved (both p<0.0005). Psoriatic plaque PD improved across the study (p<0.0005) with no signal increasing from 36.4% to 88.9% and positive PD signal decreasing from 63.6% to 11.1% of the plaques.

CONCLUSIONS

Treatment with anti-TNF-α infliximab improves the symptoms of patients with PsA at joint and psoriatic skin levels from a clinical and ultrasonographic perspective.

Adipokines in psoriatic arthritis patients: the correlations with osteoclast precursors and bone erosions

Significant bone remodeling with disordered osteoclastogenesis has been implicated in the pathogenesis of psoriatic arthritis (PsA). And there is a high prevalence of the metabolic syndrome (MS) in PsA patients. Adipokines, especially leptin and adiponectin, have recently been reported to be involved in the development and regulation of some autoimmune diseases. In this study, we examined the alternation of circulating osteoclastogenesis related cytokines [tumor necrosis factor-α (TNF-α), osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL)] and adipokines (leptin, adiponectin, resistin, chemerin, omentin) in PsA patients, and analysed the correlations between these factors and osteoclast precursors numbers, radiographic damage scores, and disease activity index. 41 PsA patients, 20 psoriasis patients, and 24 healthy controls were recruited. Blood samples were obtained for detecting the levels of TNF-α, OPG, RANKL and the adipokines. The numbers of osteoclast precursors (OCs) in peripheral blood were assessed. Radiographs of affected joints in PsA patients were scored for erosion, joint-space narrowing, osteolysis, and new bone formation. Compared with healthy controls, patients with PsA had higher TNF-α, RANKL, OCs, leptin and omentin but lower adiponectin and chemerin. Increased serum levels of TNF-α, RANKL, leptin, and omentin were positively correlated with OCs numbers. In contrast, serum adiponectin levels were decreased in PsA patients and negatively correlated with OCs numbers. TNF-α, RANKL and leptin were positively correlated with Psoriatic Arthritis Joint Activity Index (PsAJAI). Only TNF-α was positively correlated with radiographic damage scores. Our data demonstrated that systemic expression of soluble mediators of osteoclastogenesis and adipokines were disordered in PsA. Certain adipokines were elevated in the circulation of patients with PsA and might contribute to pathogenesis of arthritis. Prospective studies will be of interest to determine the pluripotent effects of adipokines on osteoclastogenesis in chronic inflammatory rheumatic diseases. Future studies may lead to novel therapeutic strategies.

Predictors of functional impairment and pain in erosive osteoarthritis of the interphalangeal joints: comparison with controlled inflammatory arthritis

OBJECTIVE

To compare levels of pain and functional limitation in patients with erosive osteoarthritis (OA) of the interphalangeal finger joints with those in patients with nonerosive OA and patients with controlled inflammatory arthritis affecting the hands, and to explore predictors of functional impairment in erosive OA.

METHODS

A cross-sectional study including 270 patients with OA of the hands who were referred to rheumatology clinics was performed. A group of patients with inflammatory arthritis (rheumatoid arthritis or psoriatic arthritis) with a low Disease Activity Score in 28 joints (<3.2; n = 79) was examined. Levels of functional impairment (measured by the Functional Index for Hand OA [FIHOA] and Australian/Canadian OA Hand Index [AUSCAN]) and pain were compared between the groups. Predictors of functional impairment in erosive OA were evaluated by generalized linear models.

RESULTS

Of 270 patients with hand OA, 167 (61.9%) were classified as having erosive OA. Despite a higher percentage of patients taking analgesics (almost 60%), patients with erosive OA had worse functional outcome and pain scores than patients with controlled inflammatory arthritis or nonerosive OA. Pain scores remained significantly higher in patients with erosive OA after correction for potential confounders. FIHOA and AUSCAN function scores showed a trend toward more disability in patients with erosive OA. Female sex and the number of radiographic affected joints (consisting of joints in the erosive and remodeled radiographic phases) were the strongest predictors of functional impairment in erosive OA. Whether the carpometacarpal joints were affected did not influence functional status in patients with erosive OA.

CONCLUSION

Our findings indicate that patients with erosive OA have more functional impairment and significantly more pain compared to patients with controlled inflammatory arthritis affecting the hands. This highlights the significant clinical burden of erosive OA and warrants the search for new treatment strategies.

Osteoporosis and psoriatic arthritis

Osteoporosis (OP) is a skeletal disorder characterized by compromised bone strength that predisposes to an increased risk of fracture. The prevalence of OP in the general population is very high as established in several studies, and OP represents one of the possible aspects of bone involvement in arthritis. In psoriatic arthritis this involvement is particularly complex because it affects not only mechanisms of bone loss but also of bone formation. We will discuss these aspects and the available epidemiological data.

Th17 and interleukin 23 in the pathogenesis of psoriatic arthritis and spondyloarthritis

Psoriatic arthritis and spondyloarthritis (SpA) are complex immune-mediated diseases affecting peripheral and axial joints. T cells have been considered fundamental in triggering the disease and maintaining the process in the chronic phase. The recent discovery of the CD4+ Th17 lymphocyte subset and the interleukin 23/interleukin 17 axis has further contributed to the definition of unknown pathways, challenging previous models and the role of Th1/Th2 T cells in immune mediated diseases, including SpA.

New developments in magnetic resonance imaging of the nail unit

The evolution of dedicated magnetic resonance imaging (MRI) musculoskeletal equipment allows new sequences and better images of the nail unit. The use of MRI has modified the imaging strategies used in treating inflammatory arthritis. In the case of psoriatic arthritis (PsA), the MRI study of the nail unit identifies nail involvement, which appears as an initial lesion for the induction of distal phalanx damage and consequently of distal interphalangeal joint arthritis. All patients with psoriasis, even in the absence of a clinically evident onychopathy, show characteristic MRI changes in the nail. This evidence could have a practical diagnostic value, because MRI study of the nail could document diagnosis in patients with undifferentiated spondyloarthropathies who have a barely evident psoriasis. We discuss the advantages and problems related to the use of low-field and high-field MRI in the study of the nail unit of patients with PsA.

Swollen joint count in psoriatic arthritis is associated with progressive radiological damage in hands and feet

OBJECTIVES

Psoriatic arthritis (PsA) may progress to joint damage. Determining clinical predictors of joint damage assessed by radiography is important. The aim of this study was to determine clinical factors as possible predictors for radiological damage in hands and feet of PsA patients with a 12-month follow-up.

METHODS

We conducted a retrospective study on 53 PsA patients who were taking disease-modifying anti-rheumatic drugs (DMARDs) and/or tumour necrosis factor (TNF)-alpha-blockers at a fixed dosage. The patients were observed in 118 follow-up visits (intervals of 12 months ± 3 months), according to a clinical and radiological protocol which included the documentation of the number of swollen and tender joints in hands and feet, the applied therapy, psoriasis, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and global health assessment. Outcome was defined as radiographic damage of hands and feet (Ratingen score). For the statistical analysis the Chi-Square test for 2x2 crosstables (with Fisher's correction, as required) was used.

RESULTS

Progressive radiological damage was more frequent among patients with an increasing swollen joint count (8 of 26 visits; 30.8%) than among those with a stable or decreased number of swollen joints (5 of 89 visits; 5.6%; p=0.001). The analysis of the patients stratified into the different treatment modalities resulted in a significant higher rate of radiological progress (20.8%) in patients on DMARD therapy compared with TNF-alpha blocking agents (0%) (p=0.009).

CONCLUSIONS

During a 12-month follow-up of PsA patients, an increasing number of swollen joints heralds progression of radiological damage. TNF-alpha-blocker therapy appears to be superior to DMARDs in the protection from radiological progress.

Analysis of granulysin-mediated cytotoxicity in peripheral blood of patients with psoriatic arthritis

The objective of the present study was to investigate possible changes in granulysin (GNLY)-mediated cytotoxicity of peripheral blood lymphocytes in psoriatic arthritis (PsA) patients with respect to different phases of the disease. We prospectively enrolled 25 PsA patients in the active phase, 26 PsA patients in remission and 24 healthy controls. The simultaneous detection of intracellular GNLY and cell surface antigens (CD3 and CD56) was performed with flow cytometry. GNLY apoptotic protein was visualised by immunocytochemistry. Natural killer (NK) cell cytotoxicity was analysed with a cytotoxicity assay against human erythroleukaemia K-562 cells. The percentage of GNLY(+) cells did not differ significantly between PsA patients in the acute phase and those in remission; however, it was always higher than in healthy examinees due to the increased percentage of GNLY(+) cells within T cells, NKT cells, and both, and in the CD56(+dim) and CD56(+bright) NK subsets. The mean fluorescence intensity for GNLY was higher in all lymphocyte subpopulations in the acute phase than in remission and in healthy controls. Accordingly, GNLY-mediated NK cell cytotoxicity against K-562 cells of active phase PsA patients was significantly higher than that in patients in remission or in healthy controls. These findings demonstrated the involvement of GNLY in the worsening of PsA and suggested that GNLY mediated the development of joint lesions.

Clinical presentation of psoriatic arthritis

Psoriatic arthritis is a spondyloarthropathy which occurs in patients with skin and/or nail psoriasis. Basing its characterization on morphological purposes, several types of arthritis have been described. Alternatively, we propose a simplified classification into three subsets, focusing on the levels of expression of cutaneous and articular elements which devise this syndrome. The first is established psoriatic arthritis which occurs in patients with evident or remittent skin and/or nail psoriasis. Its clinical spectrum consists of the five subsets classically described by Moll and Wright in 1973. The second is psoriatic arthritis "sine psoriasis" which occurs in subjects without psoriasis but with a family history of the disease in first or second-degree relatives. The third is early psoriatic arthritis which consists of an articular involvement of recent onset, occurring in subjects belonging to established or sine psoriasis subsets.

Synovitis in psoriatic arthritis: immunohistochemistry, comparisons with rheumatoid arthritis, and effects of therapy

Psoriatic arthritis (PsA) is a chronic inflammatory arthropathy associated with psoriasis that affects the peripheral joints, spine, and entheses. Most patients with PsA present with peripheral synovitis of the oligoarticular or polyarticular subtype. As one of the targets of this disease, studies on the synovium may provide insight into the mechanisms involved in this condition. Key findings from the available studies comparing synovial tissue of PsA and rheumatoid arthritis patients are discussed in this review. Also, changes in the synovial infiltrate, expression of proinflammatory cytokines and adhesion molecules, and vascularity in synovial tissue after treatment with various medications are addressed. Finally, a model for proof-of-principle study design using serial synovial biopsies is described, which could be used to predict clinical (in)efficacy in early clinical trial design in PsA.

TSG-6 inhibits osteoclast activity via an autocrine mechanism and is functionally synergistic with osteoprotegerin

OBJECTIVE

TSG-6 (the product of tumor necrosis factor [TNF]-stimulated gene 6) has a potent inhibitory effect on RANKL-mediated bone erosion. The aim of this study was to compare the activity of TSG-6 with that of osteoprotegerin (OPG) and to investigate its role as an autocrine modulator of cytokine-mediated osteoclast formation/activation. We also determined TSG-6 expression in inflammatory joint disease.

METHODS

The effects of TSG-6, OPG, and the inflammation mediators TNFα, interleukin-1 (IL-1), and IL-6 on the formation of osteoclasts from peripheral blood mononuclear cells and synovial fluid (SF) macrophages were determined by tartrate-resistant acid phosphatase staining. Lacunar resorption and filamentous actin ring formation were measured as indicators of osteoclast activity. The amount of TSG-6 in culture media or SF was quantified by enzyme-linked immunosorbent assay, and expression of TSG-6 in synovial tissue was assessed by immunohistochemistry.

RESULTS

TSG-6 acted in synergy with OPG to inhibit RANKL-mediated bone resorption and was produced by osteoclast precursors and mature osteoclasts in response to TNFα, IL-1, and IL-6. Expression of TSG-6 correlated with inhibition of lacunar resorption; this effect was ameliorated by an anti-TSG-6 antibody. The level of TSG-6 protein was determined in SF from patients with various arthritides; it was highest in patients with inflammatory conditions such as rheumatoid arthritis, in which it correlated with the amount of TSG-6 immunostaining in the synovium. TSG-6 inhibited the activation but not the formation of osteoclasts from SF macrophages.

CONCLUSION

In the presence of inflammatory cytokines, osteoclasts produced TSG-6 at concentrations that are sufficient to inhibit lacunar resorption. This may represent an autocrine mechanism to limit the degree of bone erosion during joint inflammation.

Zoledronic acid does not reduce MRI erosive progression in PsA but may suppress bone oedema: the Zoledronic Acid in Psoriatic Arthritis (ZAPA) Study

BACKGROUND

The effect of zoledronic acid (ZA) on articular bone in patients with psoriatic arthritis (PsA) was investigated using MRI.

METHODS

Patients with erosive PsA were randomised to receive 3-monthly infusions of ZA or placebo for 1 year. An additional 'tests alone' group received no infusions. Clinical assessments and MRI scans were performed at baseline and 1 year.

RESULTS

Paired 1.5T MRI scans were available in 22 patients including 6 who received ZA and 16 who did not (non-ZA = 6 placebo + 10 'tests alone' patients). The Disease Activity Score (28 swollen and tender joints, C reactive protein fell over 12 months to a greater degree in patients on ZA than in non-ZA patients (-1.6 vs -0.3, p=0.023). The MRI bone oedema score decreased in the ZA group (15.5 to 8.5) but increased in the non-ZA group (14.0 to 18.0) (p= 0.0056) with regression of bone oedema at 13.5% of sites in ZA patients vs 1.3% in non-ZA patients (p = 0.0073) and progression in 1.3% of sites in ZA patients vs 6.9% in non-ZA patients (p = 0.072). There was no difference between groups in change in MRI erosion score.

CONCLUSIONS

In this pilot study ZA reduced the progression of MRI bone oedema, indicating probable suppression of osteitis concordant with reduction in clinical measures of disease activity.

Subtype specific genetic associations for juvenile idiopathic arthritis: ERAP1 with the enthesitis related arthritis subtype and IL23R with juvenile psoriatic arthritis

INTRODUCTION

Juvenile idiopathic arthritis (JIA) is an umbrella term for all chronic childhood arthropathies and can be divided into seven subtypes. It includes the enthesitis related arthritis (ERA) subtype which displays symptoms similar to ankylosing spondylitis (AS) and juvenile-onset psoriatic arthritis which has similarities to psoriatic arthritis (PsA) and psoriasis (Ps). We, therefore, hypothesized that two well-established susceptibility loci for AS and Ps, ERAP1 and IL23R, could also confer susceptibility to these JIA subtypes.

METHODS

Single nucleotide polymorphisms (SNPs) in ERAP1 (rs30187) and IL23R (rs11209026) were genotyped in JIA cases (n = 1,054) and healthy controls (n = 5,200). Genotype frequencies were compared between all JIA cases and controls using the Cochrane-Armitage trend test implemented in PLINK. Stratified analysis by ILAR subtype was performed.

RESULTS

The ERA subtype showed strong association with ERAP1 SNP (P trend = 0.005). The IL23R SNP showed significant association in the PsA subtype (P trend = 0.04). The SNPs were not associated with JIA overall or with any other subtype.

CONCLUSIONS

We present evidence for subtype specific association of the ERAP1 gene with ERA JIA and the IL23R gene with juvenile-onset PsA. The findings will require validation in independent JIA datasets. These results suggest distinct pathogenic pathways in these subtypes.