EULAR recommendations for the management of psoriatic arthritis with pharmacological therapies: 2019 update

OBJECTIVE

To update the European League Against Rheumatism (EULAR) recommendations for the pharmacological treatment of psoriatic arthritis (PsA).

METHODS

According to the EULAR standardised operating procedures, a systematic literature review was followed by a consensus meeting to develop this update involving 28 international taskforce members in May 2019. Levels of evidence and strengths of recommendations were determined.

RESULTS

The updated recommendations comprise 6 overarching principles and 12 recommendations. The overarching principles address the nature of PsA and diversity of both musculoskeletal and non-musculoskeletal manifestations; the need for collaborative management and shared decision-making is highlighted. The recommendations provide a treatment strategy for pharmacological therapies. Non-steroidal anti-inflammatory drugs and local glucocorticoid injections are proposed as initial therapy; for patients with arthritis and poor prognostic factors, such as polyarthritis or monoarthritis/oligoarthritis accompanied by factors such as dactylitis or joint damage, rapid initiation of conventional synthetic disease-modifying antirheumatic drugs is recommended. If the treatment target is not achieved with this strategy, a biological disease-modifying antirheumatic drugs (bDMARDs) targeting tumour necrosis factor (TNF), interleukin (IL)-17A or IL-12/23 should be initiated, taking into account skin involvement if relevant. If axial disease predominates, a TNF inhibitor or IL-17A inhibitor should be started as first-line disease-modifying antirheumatic drug. Use of Janus kinase inhibitors is addressed primarily after bDMARD failure. Phosphodiesterase-4 inhibition is proposed for patients in whom these other drugs are inappropriate, generally in the context of mild disease. Drug switches and tapering in sustained remission are addressed.

CONCLUSION

These recommendations provide stakeholders with an updated consensus on the pharmacological management of PsA, based on a combination of evidence and expert opinion.

Enhanced endogenous bone morphogenetic protein signaling protects against bleomycin induced pulmonary fibrosis

BACKGROUND

Effective treatments for fibrotic diseases such as idiopathic pulmonary fibrosis are largely lacking. Transforming growth factor beta (TGFβ) plays a central role in the pathophysiology of fibrosis. We hypothesized that bone morphogenetic proteins (BMP), another family within the TGFβ superfamily of growth factors, modulate fibrogenesis driven by TGFβ. We therefore studied the role of endogenous BMP signaling in bleomycin induced lung fibrosis.

METHODS

Lung fibrosis was induced in wild-type or noggin haploinsufficient (Nog +/LacZ ) mice by intratracheal instillation of bleomycin, or phosphate buffered saline as a control. Invasive pulmonary function tests were performed using the flexiVent® SCIREQ system. The mice were sacrificed and lung tissue was collected for analysis using histopathology, collagen quantification, immunohistochemistry and gene expression analysis.

RESULTS

Nog +/LacZ mice are a known model of increased BMP signaling and were partially protected from bleomycin-induced lung fibrosis with reduced Ashcroft score, reduced collagen content and preservation of pulmonary compliance. In bleomycin-induced lung fibrosis, TGFβ and BMP signaling followed an inverse course, with dynamic activation of TGFβ signaling and repression of BMP signaling activity.

CONCLUSIONS

Upon bleomycin exposure, active BMP signaling is decreased. Derepression of BMP signaling in Nog +/LacZ mice protects against bleomycin-induced pulmonary fibrosis. Modulating the balance between BMP and TGFβ, in particular increasing endogenous BMP signals, may therefore be a therapeutic target in fibrotic lung disease.

Absence of GDF5 does not interfere with LPS Toll-like receptor signaling

OBJECTIVES

Growth and differentiation factor 5 (GDF5), member of TGFBeta superfamily, has been implicated in limb development, and is known to play an important role in joint formation. Its absence leads to brachypodism in mice and a number of skeletal malformation syndromes in humans. Recently, an association was shown between osteo-arthritis and a 5' UTR polymorphism in GDF5 gene. In addition, the role of GDF5 may reach beyond the musculoskeletal system. GDF5 appears present in a lipopolysaccharide (LPS) receptor cluster. Absence of GDF5 may limit the response to LPS. This may have consequences for immune responses and macrophage function in general, and for arthritis in particular. Here we compared the sensitivity of Gdf5(Bp-J/Bp-J) mice and wild type (WT) mice to LPS.

METHODS

Peritoneal macrophages from Gdf5(Bp-J/Bp-J) mice and WT mice were stimulated for 18h with LPS (0, 10 or 100 ng/ml). The supernatant was collected and TNF release was measured by ELISA and by an indirect luciferase assay using LNF-luc C3 cells. Gdf5(Bp-J/Bp-J) mice and WT mice were injected with LPS i.p. (30 mg/kg) and LPS induced lethality was checked every 3 hours for 36 hours.

RESULTS

Gdf5(Bp-J/Bp-J) macrophages showed no difference in TNF expression upon LPS stimulation measured by ELISA and by indirect luciferase assay. Gdf5(Bp-J/Bp-J) mice died upon a lethal dose of LPS, as is seen in WT controls.

CONCLUSION

Absence of Gdf5 appears not to affect the LPS response. Mice with a reduced expression of Gdf5 can be used in disease models which are dependent on LPS boost.

Deletion of frizzled-related protein reduces voluntary running exercise performance in mice

OBJECTIVE

To study the effect of frizzled-related protein (Frzb) deletion in mice on voluntary running wheel exercise performance and osteoarthritis.

METHODS

At the age of 7 weeks, Frzb(-/-) and wild-type mice were grouped and a running wheel was introduced into the cage. At week 8, all mice were caged solitarily with a running wheel available. Mice were allowed free exercise for 6-12 months and distances run were recorded daily. Non-running mice were used as additional control group. X-rays of knees and hips were taken at different time points. At the end of the experiment, mice were sacrificed and joints were processed for histological evaluation. Cartilage damage, synovitis and osteophyte formation were scored. Muscle fiber composition of the soleus and extensor digitorum longus was studied by immunofluorescence.

RESULTS

At the age of 6 months, both female and male wild-type mice showed a significantly greater exercise performance than the Frzb(-/-) mice (P<0.05). At 1 year, the difference was still significant for male mice, but not for females. Running exercise did not significantly affect severity of osteoarthritis. No statistical differences in osteoarthritis severity were seen between Frzb(-/-) mice and wild-type mice. No differences were seen in muscle composition between Frzb(-/-) mice and wild-type mice.

CONCLUSION

Absence of Frzb in mice reduced voluntary exercise performance in running wheels. These experiments demonstrate that the effects of genes in mice can also be evaluated using functional outcomes such as running wheel exercise performance, similar to evolving practice in human clinical trials.

Detection, identification and in vivo treatment responsiveness of bone morphogenetic protein (BMP)-activated cell populations in the synovium of patients with rheumatoid arthritis

Objective:

To characterise the bone morphogenetic protein (BMP) target cells positive for phosphorylated (P)-SMAD1/5, in rheumatoid arthritis (RA) synovium.

Methods:

Synovial biopsies were obtained by needle arthroscopy. Anti-P-SMAD1/5 antibodies were used for Western blot (WB) on protein extracts from RA and normal synovium and for immunostaining of synovial biopsy sections. Positive cells were further identified by double staining for CD3, CD20, CD68, CD138, CD90, α smooth muscle actin (SMA), endoglin (CD105) and von Willebrand factor (VWF). In sections from early patients with RA taken before and under antirheumatic treatment, the degree of inflammation and activation of the BMP pathway were quantified.

Results:

P-SMAD1/5 protein was detected by WB in RA and to a lesser extent in normal synovium. Different P-SMAD1/5 positive cell populations were identified in RA synovium, mainly in perivascular and sublining cells. P-SMAD1/5 positive perivascular cells were αSMA positive and located around VWF positive endothelial cells. Some CD90 positive synovial fibroblasts were P-SMAD1/5 positive, as was part of the CD68 positive synovial cells but other cells of the haematopoietic lineage showed no SMAD1/5 phosphorylation. Treatment resulted in an absolute but not relative decrease in BMP activation in the synovium.

Conclusion:

BMP-activated cells belong to distinct stromal compartments in RA synovium and some of them express markers associated with the mesenchymal progenitor cell lineage. Antirheumatic treatment effectively downregulates synovial inflammation, but BMP activation in the synovium does persist albeit reduced.

Activation of nuclear factor kappa B and mitogen activated protein kinases in psoriatic arthritis before and after etanercept treatment

OBJECTIVE

To study activation of intracellular pathways depending on nuclear factor kappa B (NFkappaB) and mitogen activated kinases (MAPK) in the synovium of patients with psoriatic arthritis before and after treatment with etanercept.

METHODS

Synovial biopsies were obtained by needle arthroscopy of the knee in 9 patients with active psoriatic arthritis before the initiation of etanercept. Follow-up biopsies were taken in the same knee after 6 months. Synovitis was studied by histology. Pathway activation was studied by immunofluorescense for phosphorylated ERK, phosphorylated p38, phosphorylated JNK or phosphorylated inhibitor of kappa B (IkappaBalpha) using digital image analysis.

RESULTS

Histological severity scores were significantly reduced after etanercept treatment. Activation of NFkappaB signaling was found in the lining layer, and in infiltrating and peri-vascular cells in the sublining zone. Activated p38 was present in both lining and sublining layer. In the sublining layer, positive cells were found in inflammatory infiltrates, in perivascular zones and in the endothelium. Activated ERK was mainly present in the sublining layer, both in mononuclear cell infiltrates and perivascularly. Occasional positive cells were found in the lining layer. Activation of JNK was recognized in cells of the lining layer, in some of the sublining cell infiltrates and the perivascular compartment.

CONCLUSIONS

Etanercept therapy resulted in a significant decrease in NFkappaB, JNK and ERK, but not in p38 activation. Persistent activation of these pathways, albeit reduced, may trigger positive feedback loops and flares of arthritis after cessation of etanercept.

Identification of distinct gene expression profiles in the synovium of patients with systemic lupus erythematosus

OBJECTIVE

Synovitis is a common feature of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), but the pattern of joint involvement differs in each disease. This study was undertaken to investigate the global gene expression profiles in synovial biopsy tissue from the swollen knees of untreated SLE patients (n = 6), RA patients (n = 7), and osteoarthritis (OA) patients (n = 6).

METHODS

Synovial biopsy samples were obtained from the affected knees of patients in the 3 groups by needle arthroscopy. Half of the material was used for extraction of total RNA, amplification of complementary RNA, and high-density oligonucleotide spotted hybridization arrays. On the remaining tissue samples, real-time reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemical experiments were performed to confirm the microarray data.

RESULTS

SLE synovial biopsy tissue displayed a significant down-regulation of genes involved in extracellular matrix (ECM) homeostasis and a significant up-regulation of interferon-inducible (IFI) genes. Real-time RT-PCR experiments confirmed the up-regulation of selected IFI genes (IFI27, IFI44, and IFI44L) in the SLE synovial tissue. Immunohistochemical analyses showed that 3 molecules involved in ECM regulation, chondroitin sulfate proteoglycan 2, latent transforming growth factor beta binding protein 2, and fibroblast activation protein alpha, were significantly down-regulated in SLE synovium. In contrast, immunostaining for IFI27, Toll-like receptor 4, and STAT-1 resulted in higher quantitative scores in SLE synovial tissue, which could be attributed to the fact that the RA samples had a large population of inflammatory cell infiltrates that were negative for these markers.

CONCLUSION

Arthritis in SLE has a very distinct molecular signature as compared with that in OA and RA, characterized by up-regulation of IFI genes and down-regulation of genes involved in ECM homeostasis.

Efficacy, effectiveness and safety of etanercept in monotherapy for refractory psoriatic arthritis: a 26-week observational study

OBJECTIVES

To investigate the efficacy, effectiveness and safety of etanercept, a soluble tumour necrosis factor-alpha receptor, in a prospective observational cohort of patients with refractory psoriatic arthritis and polyarticular involvement.

METHODS

Twenty patients with psoriatic arthritis refractory to conventional anti-rheumatic drugs were treated with etanercept 25 mg subcutaneously twice a week for 26 weeks. Efficacy and safety were recorded at weeks 2, 6, 10, 16, 20 and 26. Effectiveness, defined as clinical remission, reduction of 50% in clinical parameters and concomitant NSAID use, was evaluated at 26 weeks.

RESULTS

Etanercept therapy was efficacious in this cohort as 85% of the patients met the Psoriatic Arthritis Response Criterion at week 26. Effectiveness of etanercept for the individual patient was demonstrated, since at least 50% of the patients had a 90 and 85% improvement in swollen and tender joint count, respectively, and a 71% improvement in the Health Assessment Questionnaire at week 26. Four patients showed complete remission and NSAIDs were stopped in 10/15 patients. The most common adverse events were upper respiratory tract infections. Interestingly, in two patients psoriasis worsened during the study, unrelated to the course of arthritis. The administration of etanercept was interrupted in three patients for adverse events: one septic bursitis, one myocardial infarction and one tooth abscess. After resolution of the adverse events, etanercept was successfully reintroduced.

CONCLUSIONS

Etanercept in monotherapy is efficacious, effective and safe in the majority of patients with refractory psoriatic arthritis.

Ankylosing enthesitis, dactylitis, and onychoperiostitis in male DBA/1 mice: a model of psoriatic arthritis

OBJECTIVES

To further characterise spontaneous arthritis in aging male DBA/1 mice as a model of spondyloarthropathy and psoriatic arthritis with particular attention to signs of inflammation and nail involvement.

MATERIALS AND METHODS

Aging male DBA/1 mice from different litters were caged together (4-6 mice per cage) at the age of 12 weeks, checked twice a week for signs of arthritis, and killed at different times. Hind paws were dissected and processed for histology.

RESULTS

Disease incidence varied between 50% and 100% in four different experiments. Besides clinical signs of arthritis, nail abnormalities were noticed. Pathological examination showed the occurrence of dactylitis characterised by diffuse neutrophil infiltration in 6 of 50 paws examined. Onycho-periostitis with progressive destruction of the nail bed and the underlying distal phalanx was seen in 5 of 50 paws examined.

CONCLUSIONS

Although dactylitis and onychoperiostitis are rare manifestations of the disease process, these data strongly suggest that spontaneous arthritis in aging male DBA/1 mice shares important features with human psoriatic arthritis. This model may therefore be an important tool to study links between stress, sex, inflammation, and new bone formation with particular relevance to human psoriatic arthritis.

In vitro growth rate of fibroblast-like synovial cells is reduced by methotrexate treatment

BACKGROUND

Fibroblast-like synovial cells (FLS) can be cultured and expanded in vitro in monolayer. Little is known about the growth characteristics of FLS derived from different patients.

OBJECTIVE

To study FLS cultures, with particular attention to differences in growth rate of FLS from patients with rheumatoid arthritis (RA) and from other arthritic patients. Additionally, to analyse the influence of methotrexate (MTX) treatment, patient age, and disease duration on FLS growth characteristics.

MATERIALS AND METHODS

FLS were isolated from needle arthroscopy biopsy specimens. Twenty four patients (11 RA, 8 spondyloarthropathy, 1 osteoarthritis, and 4 undifferentiated arthritis) were studied. FLS population doubling time was determined between passage 2 and passage 5. Differences in population doubling time between RA and non-RA FLS and between FLS from patients receiving MTX and those not receiving this drug were analysed. In addition, possible correlations between FLS population doubling time and patient age or disease duration were examined.

RESULTS

In vitro monolayer FLS cultures from needle arthroscopy biopsy specimens showed linear growth characteristics. Cell growth rate was not correlated with type of disease. Cells from patients undergoing treatment with MTX showed a longer population doubling time than FLS from patients not receiving this drug (Mann-Whitney test, p<0.05). No correlation was found with patient age or disease duration.

CONCLUSION

The results suggest that FLS growth in monolayer is not dependent on the disease affecting the joint. MTX treatment, however, was more relevant in determining FLS growth rate.

Niemann-Pick disease type B: an unusual clinical presentation with multiple vertebral fractures

We report here a unique case of a 55-year-old woman presenting with a clinical picture of Parkinson disease, severe back pain, splenomegaly, and pronounced dyspnea. Radiographic examination of the spine showed multiple vertebral fractures. Niemann-Pick disease type B was diagnosed by findings of lipid-loaded histiocytes and a strongly reduced sphingomyelinase enzyme activity. She was homozygous for the deletion of codon 608 (delR608), which encodes an arginine residue in the Acid Sphingomyelinase gene. To investigate the cause of the unusual vertebral fractures, we screened for polymorphisms previously described as possibly associated with increased risk for osteoporosis and fractures. Our patient was heterozygous for the polymorphisms of the vitamin D receptor gene, the estrogen receptor gene, and the collagen 1A1gene. Increased physical activity after Parkinson treatment, a genetic predisposition, together with worsening disease due to interfering medications could explain the dramatic presentation of this patient. She was treated with cholesterol lowering drugs such as statins to decrease sphingomyelin synthesis, avoidance of drugs that inhibit sphingomyelinase, and bisphosphonates. No new fractures have occurred, but the interstitial lung disease has progressed.