Acute onset of psoriatic spondyloarthritis as a new manifestation of post-streptococcal reactive arthritis: a case series

Acute rheumatic fever and Post-streptococcal reactive arthritis

Acute rheumatic fever (ARF) and poststreptococcal reactive arthritis (PSRA) represent two distinct but related poststreptococcal conditions, both arising from an autoimmune response following Group A streptococcal (GAS) infection, typically pharyngitis. Although both illnesses have a shared trigger, their clinical presentations and long-term consequences differ markedly. ARF, a systemic inflammatory disorder, can impact several organs, particularly the heart, potentially resulting in chronic rheumatic heart disease with irreversible valve damage. The cornerstone of ARF treatment includes Streptococcus eradication therapy, symptom management, and secondary prophylaxis to prevent recurrence. In contrast, PSRA primarily presents as non-infectious, nonmigratory, persistent arthritis without carditis and generally resolves without lasting sequelae. Distinguishing PSRA from ARF is crucial for appropriate management and to avoid unnecessary long-term antibiotic prophylaxis. This review focuses on the key clinical features and diagnostic approaches for ARF and PSRA, along with an overview of their management strategies.

Management of postinfectious inflammatory arthritis

PURPOSE OF REVIEW

Postinfectious inflammatory arthritis can result from various pathogens, including bacteria, viruses, fungi, and parasites. Prompt identification and treatment of acute infection is vital, but some cases progress to chronic arthritis despite successful treatment of infection. Postinfectious inflammatory arthritis varies from mild, self-limited arthralgia to severe, refractory arthritis, necessitating ongoing disease-modifying treatment. This review explores the spectrum of postinfectious inflammatory arthritis to provide insights into effective management.

RECENT FINDINGS

Research continues regarding the benefit of antimicrobial therapy, beyond treatment of the acute infection, to diminish the severity of postinfectious inflammatory arthritis. Following treatment of acute infection, most cases are self-limited so treatment is symptomatic. However, a difficult-to-predict fraction of cases develop chronic postinfectious inflammatory arthritis that can be challenging to manage. Recently, as more biologic, and targeted synthetic DMARDs have become available, treatment options have expanded.

SUMMARY

In this article, we use the term 'postinfectious inflammatory arthritis' rather than 'reactive arthritis' because it describes a broader spectrum of diseases and emphasizes the common pathogenesis of a postinfectious inflammatory process. We summarize the conventional therapies and recent management developments for the most frequently encountered postinfectious inflammatory arthritides.

Evaluation of C4 Gene Copy Number in Pediatric Acute Neuropsychiatric Syndrome

Pediatric acute-onset neuropsychiatric syndrome (PANS) is an abrupt-onset neuropsychiatric disorder. PANS patients have an increased prevalence of comorbid autoimmune illness, most commonly arthritis. In addition, an estimated one-third of PANS patients present with low serum C4 protein, suggesting decreased production or increased consumption of C4 protein. To test the possibility that copy number (CN) variation contributes to risk of PANS illness, we compared mean total C4A and total C4B CN in ethnically matched subjects from PANS DNA samples and controls (192 cases and 182 controls). Longitudinal data from the Stanford PANS cohort (n = 121) were used to assess whether the time to juvenile idiopathic arthritis (JIA) or autoimmune disease (AI) onset was a function of total C4A or C4B CN. Lastly, we performed several hypothesis-generating analyses to explore the correlation between individual C4 gene variants, sex, specific genotypes, and age of PANS onset. Although the mean total C4A or C4B CN did not differ in PANS compared to controls, PANS patients with low C4B CN were at increased risk for subsequent JIA diagnosis (hazard ratio = 2.7, p value = 0.004). We also observed a possible increase in risk for AI in PANS patients and a possible correlation between lower C4B and PANS age of onset. An association between rheumatoid arthritis and low C4B CN has been reported previously. However, patients with PANS develop different types of JIA: enthesitis-related arthritis, spondyloarthritis, and psoriatic arthritis. This suggests that C4B plays a role that spans these arthritis types.

Strong site-specific association of pharyngeal cultures with the onset of psoriatic arthritis and psoriasis, regardless of pathogen

OBJECTIVES

The objective of this study was to evaluate any association between culture site / culture result / pathogen and incident PsA or psoriasis.

METHODS

Records of all samples sent for culture from a large population during a 3-year period were linked with nationwide registry data on diagnoses and death over a 15-year period. The main outcomes of interest were incident diagnoses of PsA and psoriasis, defined by International Classification of Diseases (ICD) codes. The effect of culture site, culture result (positive vs negative), and pathogen (Streptococcus vs negative culture) on the risk of developing PsA and psoriasis was calculated using Cox proportional hazards models adjusted for age and gender.

RESULTS

A total of 313 235 bacterial cultures from 128 982 individuals were analysed. Comparing individuals with pharyngeal cultures to those with urine cultures, the hazard ratio for incident PsA was 8.78 [95% confidence interval (CI) 3.23, 23.91] and for incident psoriasis it was 8.00 (95% CI 5.28, 12.12). Most of the risk was concentrated in the first 50 days after the culture date. Increased risk was also found when comparing individuals with cultures from the pharynx with those with cultures from the nasopharynx and blood. An association with streptococci was not found, neither in the pharynx nor at any other site. A positive bacterial culture from any site was associated with reduced risk for both PsA and psoriasis.

CONCLUSION

There is a strong site-specific association between pharyngeal culture samples and an increased risk of PsA and psoriasis, regardless of the pathogen. This may indicate that the site of infection, rather than the pathogen, is associated with increased risk.

Reactive Arthritis Update: Spotlight on New and Rare Infectious Agents Implicated as Pathogens

Purpose of Review

This article presents a comprehensive narrative review of reactive arthritis (ReA) with focus on articles published between 2018 and 2020. We discuss the entire spectrum of microbial agents known to be the main causative agents of ReA, those reported to be rare infective agents, and those reported to be new candidates causing the disease. The discussion is set within the context of changing disease terminology, definition, and classification over time. Further, we include reports that present at least a hint of effective antimicrobial therapy for ReA as documented in case reports or in double-blind controlled studies. Additional information is included on microbial products detected in the joint, as well as on the positivity of HLA-B27.

Recent Findings

Recent reports of ReA cover several rare causative microorganism such as Neisseria meningitides, Clostridium difficile, Escherichia coli, Hafnia alvei, Blastocytosis, Giardia lamblia, Cryptosporidium, Cyclospora cayetanensis, Entamoeba histolytica/dispar, Strongyloides stercoralis, β-haemolytic Streptococci, Mycobacterium tuberculosis, Mycoplasma pneumoniae, Mycobacterium bovis bacillus Calmette-Guerin, and Rickettsia rickettsii. The most prominent new infectious agents implicated as causative in ReA are Staphylococcus lugdunensis, placenta- and umbilical cord–derived Wharton’s jelly, Rothia mucilaginosa, and most importantly the SARS-CoV-2 virus.

Summary

In view of the increasingly large spectrum of causative agents, diagnostic consideration for the disease must include the entire panel of post-infectious arthritides termed ReA. Diagnostic procedures cannot be restricted to the well-known HLA-B27-associated group of ReA, but must also cover the large number of rare forms of arthritis following infections and vaccinations, as well as those elicited by the newly identified members of the ReA group summarized herein. Inclusion of these newly identified etiologic agents must necessitate increased research into the pathogenic mechanisms variously involved, which will engender important insights for treatment and management of ReA.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11926-021-01018-6.

Expanding the spectrum of reactive arthritis (ReA): classic ReA and infection-related arthritis including poststreptococcal ReA, Poncet's disease, and iBCG-induced ReA

Reactive arthritis (ReA) is a form of sterile arthritis that occurs secondary to an extra-articular infection in genetically predisposed individuals. The extra-articular infection is typically an infection of the gastrointestinal tract or genitourinary tract. Infection-related arthritis is a sterile arthritis associated with streptococcal tonsillitis, extra-articular tuberculosis, or intravesical instillation of bacillus Calmette–Guérin (iBCG) therapy for bladder cancer. These infection-related arthritis diagnoses are often grouped with ReA based on the pathogenic mechanism. However, the unique characteristics of these entities may be masked by a group classification. Therefore, we reviewed the clinical characteristics of classic ReA, poststreptococcal ReA, Poncet’s disease, and iBCG-induced ReA. Considering the diversity in triggering microbes, infection sites, and frequency of HLA-B27, these are different disorders. However, the clinical symptoms and intracellular parasitism pathogenic mechanism among classic ReA and infection-related arthritis entities are similar. Therefore, poststreptococcal ReA, Poncet’s disease, and iBCG-induced ReA could be included in the expanding spectrum of ReA, especially based on the pathogenic mechanism.

Microbial-derived antigens and metabolites in spondyloarthritis

Spondyloarthritis (SpA) is a group of chronic, immune-mediated, inflammatory diseases affecting the bone, synovium, and enthesis. Microbiome, the community of microorganisms that has co-evolved with human hosts, plays a pivotal role in human health and disease. This invisible "essential organ" supplies the host with a myriad of chemicals and molecules. In turn, microbial metabolites can serve as messengers for microbes to communicate with each other and in the cross-talk with host cells. Gut dysbiosis in SpA is associated with altered microbial metabolites, and an accumulated body of research has contributed to the understanding that changes in intestinal microbiota can modulate disease pathogenesis. We review the novel findings from human and animal studies to provide an overview of the contribution of individual microbial metabolites and antigens to SpA.

Update on Post-Streptococcal Reactive Arthritis: Narrative Review of a Forgotten Disease

PURPOSE OF THE REVIEW

This topical review attempts to build the concepts of PSRA as an independent entity and discuss prevalent diagnostic criteria. It utilizes a search strategy to collate all clinical features of PSRA reported from across the world and also discusses laboratory and treatment options in brief.

RECENT FINDINGS

There are several immune-mediated diseases described after acute streptococcal infections. Post-streptococcal reactive arthritis (PSRA) is a sterile, self-limiting arthritis that occur as an immune sequelae to streptococcal infection. Though PSRA resembles the arthritis of acute rheumatic fever superficially, it is a separate entity in its own right. It is different from classical reactive arthritis too. It was being recognized worldwide and more frequently in the recent past, possibly due to heightened awareness amongst clinicians. However, research on this enigmatic immune phenomenon is limited. Most acceptable hypotheses suggest molecular mimicry sensitizing the immune system towards synovial peptides such as keratin, vimentin and laminin, leading to arthritis in a genetically predisposed individual. There is still much to be learnt from this unique disease about the vagaries of the immune system.