Psoriatic arthritis and the spectrum of syndromes related to the SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) syndrome

Radiological features of long bones in synovitis, acne, pustulosis, hyperostosis, osteitis syndrome and their correlation with pathological findings

Abstract The purpose of this study was to demonstrate the radiological features of long bones in synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome and to correlate these with the clinical findings. Eleven long bone lesions in seven cases of SAPHO syndrome were examined. The patients ranged in age from 6 to 63 years, with a mean of 47 years. In all seven cases, radiography, (99m)technetium bone scintigraphy, CT scan, and magnetic resonance imaging (MRI) were performed. In six of the cases, bone biopsy and bone culture were carried out for 7 long bones. Seven of the involved lesions were from the shaft of the femur, one each was from the neck and the shaft of the humerus, and one was from the proximal tibia. These lesions showed radiologically hyperostosis, osteolysis, and bone infarction-like lesion. Osteolysis was occasionally accompanied by sclerotic change. Hyperostosis usually showed diaphyseal involvement, presenting low signal intensity on T1- and T2-weighted MR images. Histologically, these findings corresponded to massive bone necrosis, new bone formation, fibrosis, or a mixture of these associated with mild inflammatory cell infiltration. Osteolysis involved dyaphysis, metaphysis, or epiphysis associated with arthritis, and presented low signal intensity on T1-weighted images, nonhomogeneous signal intensity lower than fat on T2-weighted images, and high signal intensity on fat suppression images. These findings corresponded to fibrosis, granulation, and inflammatory cell infiltration with lymphocyte aggregation. Bone infarction-like lesion was observed in the shaft or neck of the femur and the humerus and accompanied by calcification and cystic change. Bone cultures were negative in all cases in which bone biopsy was performed. Although hyperostosis is thought to be a characteristic bone lesion in SAPHO syndrome, the long bone lesion can occasionally show not only hyperostosis but also osteolytsis and bone infarction-like lesions.

A study of ten Japanese patients with seronegative spondylarthropathy: a tentative proposal

We reviewed ten patients with seronegative spondylarthropathy (SNSA), who all fulfilled the European Spondylarthropathy Study Group criteria for spondylarthropathy (SpA); seven patients also met the Amor criteria for SpA. Seronegative spondylarthropathy was not a uniform syndrome but rather a wide spectrum of complex disease with characteristics of sacroiliitis and enthesopathy. The most frequent symptom at diagnosis of SNSA was inflammatory low back pain, followed by asymmetric oligoarthralgia and Achilles tendonitis and/or plantar fasciitis. Systemic complications were revealed as eye and skin involvement. Imaging methods including pelvic radiography, scintigraphy, and computed tomography scanning were useful in detecting spondylarthropathic changes, which were characteristic of SNSA. Human leukocyte antigen (HLA) typing showed various patterns among patients, in which HLA-B27 was positive in three patients with ankylosing spondylitis. HLA-B51, which is a well-known genetic factor associated with Behçet's disease (BD), was positive in two patients who were apparently distinct from BD. Two patients with palmoplantar pustulosis showed symptoms and signs characteristic of SNSA. Although we have few SNSA patients in the present study, we would like to propose that HLA-B51 positive SpA would be considered as a subset of SNSA, and that pustulotic SpA also would be classified as a member of SNSA. This led us to suggest the possibility to change the concept of SNSA proposed by Moll et al. The optimal treatment remains to be defined, but sulfasalazine was effectively used with almost all patients in combination with nonsteroidal anti-inflammatory drugs.

HLA-C locus alleles may modulate the clinical expression of psoriatic arthritis

The aim of the present study was to evaluate the relative contribution of human leukocyte antigen (HLA)-C locus alleles in determining the risk and the clinical expression of psoriatic arthritis (PsA). One hundred PsA patients were randomly selected and grouped into three disease subsets: oligoarthritis (n = 40), polyarthritis (n = 25) and spondylitis (n = 35). The HLA-C locus profile of this cohort was studied by methods based on molecular biology and was compared with that of 45 patients with psoriasis vulgaris and 177 healthy blood donors from the same ethnic origin. HLA-Cw*0602 was found associated with both psoriasis (odds ratio (OR) 6.2; 95% confidence interval (CI) 3.1 to 12.5; p < 0.0001) and PsA (OR 6.2; 95% CI 3.6 to 10.8; p < 0.0001); however, this allele was equally found among the PsA subsets. HLA-Cw6-positive patients showed a longer psoriasis-arthritis latency period (p = 0.012). HLA-Cw*0701 was found under-represented in PsA in comparison with controls (OR 0.5; 95% CI 0.3 to 0.9; p = 0.04), as was HLA-Cw*0802 (OR 0.3; 95% CI 0.08 to 1; p = 0.05). A positive association was found between psoriatic spondylitis and HLA-Cw*0702 (OR 5.0; 95% CI 1.4 to 25; p = 0.01). HLA-Cw*0602 seems to confer a general risk for psoriasis, but the presence of other HLA-C locus alleles may explain an additional arthritogenic risk. HLA-C alleles may modulate some aspects of the clinical expression of PsA, but these findings need confirmation.

Pharmacogenetic of antirheumatic treatments: clinical implications

Preliminary pharmacogenetic data suggest that germline genetic informations might be of value in individualizing disease-modifying antirheumatic drugs (DMARDs) therapy in various autoimmune chronic inflammatory diseases. Either DMARDs small molecules (DMARDs-SM) or DMARDs biological therapies (DMARDs-BT) might be selected for their lower toxicity or better efficacy based on single-nucleotide polymorphisms (SNPs) of genes governing the metabolism of drugs, or the response of immune cells to proinflammatory molecules, or the proinflammatory molecular activity of immune cells. Data available for one DMARDs-SM, methotrexate, suggest that a careful assessment of the SNPs of four enzymes involved in the folate metabolism allow one to construct a genetic index of toxicity (toxicogenetic index) that might be employed in daily practice to find the patient's most at risk. Only the full knowledge of the various gene polymorphisms controlling the phenotypic manifestations of the inflammatory-immunological milieu of each rheumatic disease will allow one to obtain the clear definition of a personalized medicine. Few different cytokine gene SNPs seem to be of importance in determining the susceptibility to diseases, or the aggressiveness of diseases. The role of genetics in affecting a possible clinical response to DMARDs-BT targeting specific inflammatory molecules or their receptors still has to be defined. However, the available data suggest that cytokine (and/or receptors) gene SNPs might indeed play a role in determining the biological effects, hence the clinical effectiveness of DMARDs-BT. Crucial to this aim will be the prospective analysis of clinical benefits and safety on the basis of the at baseline stratification of gene SNPs in each chronic inflammatory rheumatic disease before starting any new DMARDs-SM or DMARDs-BT.

Case reports: aseptic femoral osteitis and sternocostal hyperostosis from SAPHO syndrome

Synovitis, acne, pustulosis, hyperostosis, and osteitis syndrome are characterized by peculiar bone lesions that commonly involve the anterior chest wall. Osteitis typically is the most prominent skeletal lesion seen in synovitis, acne, pustulosis, hyperostosis, and osteitis syndrome. We present a patient with aseptic femoral osteitis and sternocostal hyperostosis. The classic clinical, radiographic, and histologic features of this syndrome are described. Diagnosis is difficult in patients with only one symptomatic bone. The lesion often is confused with suppurative osteomyelitis because of similar clinicopathologic findings. Although the optimal treatment is unclear, it is important to consider synovitis, acne, pustulosis, hyperostosis, and osteitis syndrome in the differential diagnosis of any lytic, sclerotic, or hyperostotic bone lesion to avoid unnecessary long-term antibiotic therapy.

Endogenous interleukin-6, but not tumor necrosis factor α, contributes to the development of toll-like receptor 4/myeloid differentiation factor 88-mediated acute arthritis in mice

OBJECTIVE

To generate a mouse model of reactive arthritis (ReA), an aseptic synovitis that develops in joints distant from the primary bacterial infection site, to examine roles for Toll-like receptors (TLRs) that recognize bacterial components involved in the development of this arthritis, and to identify the cytokine(s) relevant to this arthritis.

METHODS

Mice were treated with cell wall extract from Escherichia coli (ECW) gram-negative bacterium by injection into the footpads. Seven days later, the mice were challenged with lipopolysaccharide (LPS), a TLR-4 ligand, which was injected into the knee joint cavity. To investigate the cytokine(s) involved in this arthritis, mice deficient in various arthritogenic cytokines, such as interleukin-6 (IL-6), IL-12, IL-18, interferon-gamma, and tumor necrosis factor alpha (TNFalpha), were sequentially treated with ECW and LPS.

RESULTS

ECW-primed mice manifested acute severe arthritis after intraarticular challenge with ECW or LPS, while unprimed mice exhibited modest changes after these challenges. Mutant mice lacking functional TLR-4 or myeloid differentiation factor 88 (MyD88), an adaptor molecule of TLR-4 signaling, were resistant to this arthritis. Although both TNFalpha and IL-6 were equally expressed in the joint after LPS challenge, Il6(-/-) mice, but not Tnf(-/-) mice, were resistant to ECW/LPS-induced arthritis.

CONCLUSION

Our present results clearly indicate the importance of priming with ECW and the requirement of TLR-4/MyD88-mediated IL-6, but not TNFalpha, for the development of ECW/LPS-induced arthritis. LPS-induced IL-6, in the absence of TNFalpha, mediates LPS-induced arthritis. These results suggest that IL-6 is a rational target for therapeutic regimens for inflammatory arthritis, including ReA and rheumatoid arthritis.

Rheumatic manifestations of human immunodeficiency virus infection

Rheumatic complaints are common in patients with human immunodeficiency virus (HIV) infection. With the advent of the modern combined antiretroviral treatment, life-long control of HIV infection and normalization of life expectancy in HIV-positive patients have become realistic perspectives, but new rheumatic complications, such as osteoporosis, osteonecrosis, gout, and mycobacterial and mycotic osteoarticular infections may be more prevalent. Rheumatologists, internists, and general physicians need to be familiar with the presentation and treatment of these conditions in HIV-positive patients.

Differential association of polymorphisms in the TNFalpha region with psoriatic arthritis but not psoriasis

OBJECTIVE

To investigate the potential association of tumour necrosis factor alpha (TNFalpha) microsatellite and promoter alleles with psoriatic arthritis (PsA).

METHODS

DNA from 89 white patients with PsA, 65 patients with psoriasis, and 99 healthy white controls was investigated for two TNFalpha promoter (-238 and -308) and three microsatellite polymorphisms (TNFa, c, and d). Patients had previously been studied by serology for HLA class I antigens and by sequence-specific polymerase chain reaction for DRB1* alleles. In addition, TNFalpha production of Ficoll separated peripheral blood mononuclear cells (PBMC) into culture supernatants after stimulation with lipopolysaccharide, alphaCD3 antibodies, phytohaemagglutinin, and streptococcal superantigen C was determined.

RESULTS

A significant, HLA class I independent increase of the TNFa6c1d3 haplotype was found in the group with PsA but not among patients with psoriasis (32% v. 8%, pc<0.008; relative risk (RR)=5.3). In addition, patients with PsA showed a marked decrease of the TNF308A promoter allele (6% v. 18%; pc<0.008; RR=3.5) compared with healthy controls, which was independent of the increased frequency of the -238A polymorphism in this group. PBMC from patients with PsA secreted significantly less TNFalpha than cells from patients without arthritis. In particular, the TNFa6 microsatellite was associated with decreased TNFalpha production.

CONCLUSION

These data indicate that allelic variations at the TNFalpha locus influence susceptibility to PsA. Decreased production of TNFalpha is at least in part genetically determined and might be related to the development of arthritis. However, the association of the TNF308G allele with the disease also points to other disease related haplotypes with still unknown susceptibility genes.

Insights into the Role of Infection in the Spondyloarthropathies

Certain infections play an important role in the pathogenesis of the human leukocyte antigen (HLA)-B27-associated reactive arthritis. Whether infections play a role in other forms of spondyloarthropathies is not as clear. The role of HLA-B27 as an antigen-presenting molecule is important in the pathogenesis of these diseases. Recent evidence has been obtained indicating that this molecule may have other functions unrelated to antigen-presentation in the interaction of reactive arthritis-triggering microbes and host. This paper reviews the recent studies on the role of infection in the spondyloarthropathies.

Psoriatic arthritis joint fluids are characterized by CD8 and CD4 T cell clonal expansions appear antigen driven

The CD8 alphabetaT cell receptor repertoire in joint fluid of individuals with active psoriatic arthritis contained an average of 32 major oligoclonal expansions in many variable genes of the TCR beta chain (BV) families, as shown by beta-chain CDR3 length analysis. Interestingly, a small number of oligoclonal expansions were shared between simultaneous samples of joint fluid and blood; however, most expansions found in joint fluid were not identifiable in blood emphasizing the immunologic specificity of the clonal events for the inflamed joint at a given point of time. The CD4 T cell joint fluid repertoire contained fewer and smaller oligoclonal expansions also largely restricted to the joint, suggesting that CD4 T cells participate perhaps by interacting cognitively to generate the CD8 clones. The inferred amino acid sequence of a single CD8 oligoclonal expansion revealed that they usually are composed of one or a few structurally related clones at the amino acid sequence level with beta-chains that encode identical or highly homologous CDR3 motifs. These were not shared among patients. Moreover, several clones that encoded the same amino acid sequence were found to be structurally distinct at the nucleotide level, strongly implying clonal selection and expansion is operating at the level of specific TCR-peptide interactions. The findings support a model of psoriatic arthritis inflammation involving extensive and selective Ag, likely autoantigen, driven intra-articular CD4, and CD8 T cell clonal expansions.

Successful treatment of pustulotic arthro-osteitis (Sonozaki syndrome) with systemic cyclosporin

Pustulotic arthro-osteitis, first described by Sonozaki, is a relatively rare disorder, the prevalence of which is probably underestimated in dermatological literature; its early recognition can prevent misdiagnosis, unnecessary surgery, and the use of prolonged and ineffective antibiotic treatment.

Comparison of differentiated dendritic cell infiltration of autoimmune and osteoarthritis synovial tissue

OBJECTIVE

Infiltration of rheumatoid arthritis (RA) synovial tissue (ST) by differentiated dendritic cells (DC) is a consistent feature in patients with active disease. However, mononuclear cells (MNC), including DC, may be nonspecifically chemoattracted to inflammatory sites regardless of etiology. Therefore, to evaluate the specificity of ST infiltration by differentiated DC, synovial biopsies from patients with RA, spondylarthropathy (SpA), osteoarthritis (OA), and gout were examined.

METHODS

Formalin-fixed ST sections were analyzed by double immunohistochemical staining for vascularity and infiltration by differentiated DC, lymphocytes, and macrophages.

RESULTS

DC containing nuclear RelB were found in perivascular MNC aggregates from patients with all arthritides studied. Infiltration by differentiated DC was similar in RA and SpA ST, but reduced in OA ST. Differentiated DC were always observed in close association with lymphocytes, and the correlation between these variables suggested that the infiltration of inflammatory sites by DC and lymphocytes was associated.

CONCLUSION

Perivascular infiltration by DC, lymphocytes, and macrophages is nonspecifically related to inflammation, but signals present in RA and SpA ST lead to more intense cellular infiltration and accumulation.

T-cell studies in the spondyloarthropathies

A growing body of evidence suggests that T lymphocytes play an important role in initiating and maintaining the inflammatory process characteristic of the human leukocyte antigen (HLA)-B27-associated spondyloarthropathies. T cells seem to be involved in the primary defense reaction against arthritis-triggering gram-negative bacteria at the site of extra-articular infection, in determining the systemic cytokine pattern, in the recirculation process between gut mucosa and the joint, and in mediating secondary autoimmune joint inflammation. The factors involved in disease chronicity (namely in ankylosing spondylitis and psoriatic arthritis) are still unknown. Autoreactive T cells may contribute to this process by recognition of cross-reactive self-epitopes (ie, molecular mimicry between bacterial and self-antigens). Autoreactive T cells may as well be inappropriately upregulated by bacterial superantigens, or by local inflammatory reactions leading to the uncovering of former cryptic self-epitopes. In this paper, we review recent studies on peripheral blood and synovial T cells in patients with reactive arthritis, enteropathic spondyloarthropathy, psoriatic arthritis, and ankylosing spondylitis.