Psoriatic arthritis: evolving concepts

Association between circulating 25-hydroxyvitamin D levels and psoriasis, and correlation with disease severity: a meta-analysis

BACKGROUND

Psoriasis is a chronic, autoimmune, inflammatory skin disorder. 25-hydroxy vitamin D [25(OH)D] deficiency may contribute to the pathogenesis of psoriasis through reduction in antiproliferative, anti-inflammatory and antiangiogenic activities.

AIM

To evaluate the relationship between circulating 25(OH)D levels and psoriasis, and to determine the correlation between serum/plasma 25(OH)D levels and psoriasis severity.

METHODS

We performed a meta-analysis to compare serum/plasma 25(OH)D levels between patients with psoriasis and healthy controls (HCs), and to determine the correlation coefficients between circulating 25(OH)D levels and psoriasis severity as assessed by Psoriasis Area and Severity Index (PASI).

RESULTS

Ten articles with a total of 571 patients with psoriasis and 496 HCs were included. The 25(OH)D level was significantly lower in the psoriasis group than in the HC group. Subgroup analysis by sample size revealed a significantly lower level of 25(OH)D in the psoriasis group for large (N > 80) but not for small (N < 80) sample sizes. Stratification by adjustment for age and/or sex or sample type revealed a significantly lower 25(OH)D level in the psoriasis group after adjustment for serum but not after nonadjustment for plasma. Meta-analysis of the correlation coefficients revealed a small but statistically significant positive correlation between circulating 25(OH)D levels and PASI.

CONCLUSIONS

This meta-analysis demonstrated that circulating 25(OH)D levels are lower in patients with psoriasis, and that a small but statistically significant negative correlation exists between 25(OH)D levels and psoriasis severity.

MRI findings of juvenile psoriatic arthritis

OBJECTIVE

The aim of this study was to describe the magnetic resonance imaging (MRI) features of juvenile psoriatic arthritis (JpsA) in children in order to facilitate early diagnosis and proper management.

MATERIALS AND METHODS

Two pediatric radiologists retrospectively reviewed in consensus a total of 37 abnormal MRI examinations from 31 pediatric patients (nine boys, 22 girls; age range 1-17 years; mean age 9.4 years) who had a definite diagnosis of JpsA and underwent MRI. Each MRI was evaluated for synovium abnormality (thickening and enhancement), joint effusion (small, moderate, and large), bone marrow abnormality (edema, enhancement, and location of abnormality), soft tissue abnormality (edema, enhancement, atrophy, and fatty infiltration), tendon abnormality (thickening, edema, tendon sheath fluid, and enhancement), and articular abnormality (joint space narrowing and erosion). The distribution of abnormal MRI findings among the six categories for the 37 MRI examinations was evaluated. The number of abnormal MRI findings for each MRI examination was assessed. Age at MRI examination and all six categories of abnormal MRI findings according to gender were evaluated.

RESULTS

There were a total 96 abnormal MRI findings noted on 37 abnormal MRI examinations from 31 pediatric patients. The 37 abnormal MRI examinations included MRI of the hand (n = 8), knee (n = 8), ankle (n = 5), pelvis (n = 5), temporomandibular joint (n = 4), wrist (n = 3), foot (n = 2), elbow (n = 1), and shoulder (n = 1). Twenty-eight diffuse synovial thickening and/or enhancement were the most common MRI abnormality (29.2%). Joint effusion comprised 22 abnormal MRI findings (22.9%). There were 16 abnormal MRI bone marrow edema and/or enhancement findings (16.7%), and in seven (7.3%) the edema involved non-articular sites. Soft tissue abnormality manifested as edema and/or enhancement constituted 14 abnormal MRI findings (14.5%). There were ten MRI abnormalities (10.4%) involving tendons. Articular abnormality seen as joint space narrowing and/or bone erosion comprised six abnormal MRI findings (6.2%). Most MRI examinations had more than one abnormal finding (84%). Age at which MRI examinations were performed was not significantly different between boys and girls. All six categories of abnormal MRI findings were not significantly different between boys and girls.

CONCLUSION

Children with JpsA typically present with more than one abnormal finding on their MRI studies. While synovial abnormality is the most common MR finding in children with JpsA, multi-focal bone marrow edema and enhancement at both articular and non-articular sites are also notable findings in children with JpsA. The rate of articular abnormality is much lower in children with JpsA in comparison to adults with psoriatic arthritis. Our findings suggest that MRI can play a useful role in the diagnosis and ongoing assessment of this uncommon, though important, pediatric rheumatologic disorder.

Detailed analysis of contrast-enhanced MRI of hands and wrists in patients with psoriatic arthritis

OBJECTIVE

The objective was to perform detailed analysis of the involved soft tissues, tendons, joints, and bones in the hands and wrists of patients with psoriatic arthritis (PsA).

MATERIALS AND METHODS

We reviewed 23 contrast-enhanced MR imaging studies (13 hands and 10 wrists) in 10 patients with the clinical diagnosis of PsA. We obtained clinical information from medical records and evaluated images for the presence of erosions, bone marrow edema, joint synovitis, tenosynovitis, carpal tunnel, and soft tissue involvement. Two board-certified musculoskeletal radiologists reviewed all images independently. Differences were resolved during a subsequent joint session.

RESULTS

The average duration of disease was 71.3 months, ranging from 1 month to 25 years. Eight of the 10 wrists (80%) and 6 of the 13 hands demonstrated bone erosions. Bone marrow abnormalities were shown in 5 of the 10 wrists (50%) and 4 of the 14 hands (31%). Triangular fibrocartilage tears were seen in 6 of the 10 wrists (60%). Wrist and hand joint synovitis were present in all studies (67 wrist joints and 101 hand joints). Wrist soft tissue involvement was detected in 9 of the 10 wrists (90%) and hand soft tissue involvement was present in 12 of the 13 wrists (92%). Findings adjacent to the region of soft tissue involvement included synovitis (4 wrists) and tenosynovitis (3 wrists). Bone marrow edema adjacent to the region of soft tissue involvement was seen in one wrist. Bulge of the flexor retinaculum was seen in 4 of the 10 wrists (40%) and median nerve enhancement was seen in 8 of the 10 wrists (80%). Tenosynovitis was seen in all studies (all 10 of the hands and all 13 of the wrists). The "rheumatoid" type of distribution of bony lesions was common in our study. Interobserver agreement for various findings ranged from 83% to 100%.

CONCLUSION

Contrast-enhanced MRI unequivocally demonstrated bone marrow edema, erosions, tendon and soft-tissue disease, and median nerve involvement, with good interobserver reliability in patients with PsA of the hands and wrists. Disease was more extensive in the wrists than in the hands.

MRI in psoriatic arthritis with hand and foot involvement

Evaluation of MRI-findings in patients with involvement of psoriatic arthritis (PsA) in small joints in hands and feet. Twenty-five patients with symptomatic joint involvement were studied by MRI. All patients were found to be positive for one or more imaging criteria. Soft tissue oedema was identified in 22/25 (88%) patients. Joint effusion was observed in 23/25 (92%) patients, whereas bone erosion was seen in 20/25 (80%) patients. Bone marrow oedema was evident in 21/25 (84%) cases. In 12/25 (48%) cases, bone proliferation was noted. Tendon sheath effusion was present in 17/25 (68%) patients. Contrast enhancement of the synovia was detected in all patients (n = 25) (100%), whereas adjacent periost was enhanced in 22/25 (88%) and epiphysial bone marrow in 18/25 (72%) patients. MRI allows the assessment of PsA-alterations of soft tissue, cartilage, bone, bone marrow, and adjacent tendon sheath in patients with hand and foot involvement.

Diagnosis and treatment of psoriatic arthritis

Psoriatic arthritis is a chronic, heterogeneous disease whose pathogenesis is unknown, although genetic, environmental, and immunologic factors play major roles. Psoriatic arthritis can follow an aggressive clinical course, and differentiating it from other arthropathies is sometimes difficult. Diagnosis of psoriatic arthritis is based on history, physical examination, the usual absence of rheumatoid factor, and characteristic radiographic features. At least 40% of patients with psoriatic arthritis develop radiographically detectable joint destruction; therefore, proper diagnosis and early treatment can have a significant impact on disease course and outcome. Understanding the pathogenesis of psoriatic disease has led to the use of several biologic agents that work by modulating T-cell signaling or by inhibiting key cytokines involved in inflammation, such as tumor necrosis factor (TNF). TNF inhibitors have demonstrated excellent efficacy in resolving skin and joint disease in patients with psoriatic arthritis and have been shown to be safe agents in various inflammatory disorders. This article reviews the diagnostic and treatment challenges of psoriatic arthritis as they relate to pathogenesis and burden of disease.

LEARNING OBJECTIVE

At the conclusion of this learning activity, participants should have acquired a more comprehensive knowledge of our current understanding of the classification, clinical presentation, etiology, pathophysiology, differential diagnosis, and treatment of psoriatic arthritis.