Psoriatic arthritis and alpha-interferon

Drug- or Vaccine-Induced/Aggravated Psoriatic Arthritis: A Systematic Review

INTRODUCTION

Drugs and vaccines have been less studied as inducing or aggravating factors for psoriatic arthritis (PsA) compared with psoriasis. Thus, the present study collected and summarized the publications to date about this issue.

METHODS

We conducted a systematic literature search through the PubMed, Embase, and Cochrane databases to identify all reports on potential drug- and vaccine-related PsA events until 28 February 2023.

RESULTS

In total, 179 cases from 79 studies were eligible for study. Drugs commonly reported include coronavirus disease 2019 (COVID-19) mRNA vaccines (6 cases), bacillus Calmette-Guerin (BCG) vaccine (3 cases), interferon (18 cases), immune-checkpoint inhibitors (ICI) (19 cases), and biologic disease-modifying antirheumatic drugs (bDMARDs) (127 cases). Drugs causing psoriasis may also induce or aggravate PsA (6 cases). BDMARD-related PsA mostly occurred in a "paradoxical" setting, in which the bDMARDs approved for the treatment of psoriasis induce or aggravate PsA. The reported latency may be delayed up to 2 years. Peripheral arthritis (82.3%) was the most common manifestation of drug- and vaccine-related PsA, followed by dactylitis (29.1%), enthesitis (23.4%), and spondyloarthritis (17.7%).

CONCLUSIONS

Drugs and vaccines may be implicated in the aggravation of PsA. Possible mechanisms include cytokine imbalance, immune dysregulation, or inadequate PsA treatment response compared with psoriasis. Most reports are case based without controls, so more studies are needed to further prove the causality. However, early recognition of factors causing or aggravating PsA is important to prevent the irreversible joint damage.

Psoriasis and psoriatic arthritis: separate or one and the same?

The presence and severity of skin and joint symptoms in patients with psoriasis and psoriatic arthritis frequently do not correspond, a discrepancy that has raised the question of whether they represent two related but different disease processes. The fact that some agents seem to work preferentially in one state over the other reinforces this idea. However, there are also several agents with combined efficacy against cutaneous and articular inflammation that appear to support the existence of a common aetiology. Here we review the clinical, epidemiological and genetic evidence for and against a common pathogenesis for the two diseases. We then discuss the cellular and molecular targets of their selected therapies and how they potentially implicate effector pathways as a common immunopathogenic mechanism. Finally, we examine a recently proposed model of psoriasis pathogenesis involving type 1 interferon-producing plasmacytoid dendritic cells and how it may provide further clues to the aetiological links between psoriasis and psoriatic arthritis.

Hepatitis C virus and arthritis

Arthritis is one of the several autoimmune disorders induced by HCV infection. There is not a specific clinical pattern of HCV-related arthritis, but two nonerosive subsets have more frequently been described: a RA-like polyarthritis and a less common mono-oligoarthritis involving medium-sized and large joints, often showing an intermittent course. This latter form is associated with the presence of serum cryoglobulins. Because of its variable characteristics, HCV-related arthritis must be considered in the differential diagnosis of many patients having inflammatory joint involvement. Antikeratin antibodies and possibly IgA RF can be useful in distinguishing between RA and HCV-related RA-like polyarthritis. In fact, these tests are highly specific in RA patients. In any case, the search for HCV antibodies should be more widely performed in the diagnostic approach to rheumatic diseases. An association between PsA and HCV infection has been described in the literature, but the authors were unable to confirm these data. Nonsteroidal anti-inflammatory drugs, hydroxychloroquine, and low doses of corticosteroids are the cornerstones of the treatment of HCV-related arthritis. An etiologic therapy with alpha-interferon and ribavirin is useful when required by hepatic or systemic involvement; such therapy could also be considered in selected cases of isolated arthritis that are unresponsive to other drugs. Few case reports described the onset of polyarthritis after the administration of alpha-interferon for HCV-related chronic hepatitis. This topic should be more accurately studied in the future to exclude a spurious association between the two events.