Bacterial antibodies in HLA-B27+ healthy individuals

Looking back on 51 years of the Carol Nachman Prize in Rheumatology-significance for the field of spondyloarthritis research

The city and casino of Wiesbaden, capital of the German state Hessen, have endowed the Carol Nachman Prize to promote research work in the field of rheumatology since 1972. The prize, endowed with 37,500 €, is the second highest medical award in Germany and serves to promote clinical, therapeutic, and experimental research work in the field of rheumatology. In June 2022, the 50-year anniversary was celebrated. In the symposium preceding the award ceremony, an overview was given on the significance of spondyloarthritis for the work of the awardees in the past 30 years. This overview has now been put together to inform the interested community of the work performed, including the opinion of the awardees regarding what they consider to be their most important contribution.

Murine scent mark microbial communities are genetically determined

Scent marking in mice allows males to communicate information such as territory ownership, male competitive ability and current reproductive, nutritional, social and health status. It has been suggested that female mice eavesdrop on these olfactory cues, using them as a means of selecting mates with dissimilar major histocompatibility complex (MHC) genes, known as H2 in mice. The mechanisms underpinning MHC-dependent olfactory communication remain unresolved. Using congenic mouse strains and molecular methods we explore the involvement of the microbial communities, a known source of odourants, in scent marks to test the hypothesis that the microbial communities and hence the olfactory signals are genetically determined. Here we show that the indigenous microbial community of murine scent marks is genetically determined. Both background genotype and H2 haplotype influence the community structure of the scent mark flora, removing the possibility that community composition is solely orchestrated by the MHC. Qualitative and quantitative components of the bacterial community associated with MHC haplotype and background genotype were identified. The analyses confirm that the four groups of congenic mice tested are distinguishable on basis of the microbiology of their scent marks alone, strengthening the role of microorganisms in the development of MHC-dependent odours.

The high prevalence of infections and allergic symptoms in patients with ankylosing spondylitis is associated with clinical symptoms

Ankylosing spondylitis (AS) is strongly associated with the major histocompatibility complex (MHC) class I antigen HLA-B27. This may have influence on the physiologic immune response. Whether it leads to an increased prevalence of infections and/or allergy in AS patients is unclear. This study aims to determine the prevalence of infections and allergic symptoms in patients with AS and to detect a possible association with clinical symptoms. Data on 1,080 AS patients and on 102 disc prolapse patients were collected by questionnaire. The proportion of patients with a symptomatic infection in the last year was 65.5% in AS patients in comparison with 25.5% in disc prolapse patients (p=0.0001). AS patients reported more gastrointestinal (GI) [odds ratio (OR) 5.07, 95% confidence interval (CI) 2.20-11.71], urinary tract (OR 2.81, 95%CI 1.41-5.72), and respiratory (OR 5.83, 95%CI 3.38-10.08) infections than did disc prolapse patients. Multiple infections were more common in AS patients across all infection types. Allergic symptoms were reported by AS patients more frequently than by disc prolapse patients (OR 5.13, 95%CI 3.49-8.80). Patients reporting concurrent inflammatory bowel disease were more likely to report GI (OR 3.0, 95%CI 1.9-4.8) and urinary tract (OR 1.7, 95%CI 1-2.8) infection than primary AS patients. In AS patients, infection was independently associated with female gender (OR 1.96, 95%CI 1.47-2.56), a history of significant peripheral joint inflammation (OR 1.55, 95%CI 1.18-2.05), and increasing pain duration (p=0.05). A high prevalence of common infections and allergic symptoms is seen in patients with AS, most of which are HLA-B27-positive. This may have implications both for underlying mechanisms of disease and for therapeutic options.

Normal intestinal microbiota in the aetiopathogenesis of rheumatoid arthritis

A series of observations have led to the hypothesis that normal intestinal microbiota in patients with rheumatoid arthritis may harbour, for genetic reasons, bacteria with cell walls capable of inducing arthritis. Differences occur between bacterial species, and even between strains of a single species, because some cell walls induce experimental chronic arthritis, whereas some others induce only a transient acute arthritis or no arthritis at all. In susceptible subjects, with continuous seeding of bacterial products from the gut, the synovial inflammation is followed by erosion, exposition of cartilage antigens, and self perpetuating chronic arthritis.

Influence of major histocompatibility complex on bacterial composition of fecal flora

Very little is known about how the host genome influences the composition of the gastrointestinal flora, largely due to the great number and diversity of bacteria present in the flora and the difficulties of using traditional methods of bacterial isolation and identification. We have approached the problem by studying bacterium-derived cellular fatty acids in the stool samples of six mouse strains congenic for the major histocompatibility complex (MHC). The results obtained indicate that the composition of the fecal flora is genetically regulated. In addition to undefined gene loci, MHC alone has a pronounced effect, since mice with different MHC in the same background have significantly different fecal floras. Demonstration of the genetic influence on the gastrointestinal flora opens a new approach to studying the pathogenesis of bacterially induced diseases.

Cytokines and the immunopathology of the spondyloarthropathies

In contrast to rheumatoid arthritis (RA), the triggering antigens are known in reactive arthritis (ReA) and Lyme arthritis. Thus, in these arthritides the antigen-specific T-cell response can be investigated in much detail and lessons possibly learned for other spondyloarthropathies (SpA) such as ankylosing spondylitis (AS) where T cells may well also play an important role in the pathogenesis. This article focusses on the immunopathology of the SpA, ReA, and AS with special reference to T cells and cytokines.

Prevalence of spondylarthropathies in HLA-B27 positive and negative blood donors

OBJECTIVE

To determine the overall prevalence of spondylarthropathy (SpA) among whites.

METHODS

To screen for SpA symptoms, such as inflammatory back pain (IBP), joint swelling, psoriasis, and uveitis, or a specific family history, questionnaires were mailed to 348 blood donors (174 HLA-B27 positive and 174 HLA-B27 negative). From the responding 273 persons (78%; 140 B27 positive, 133 B27 negative), 126 were selected for further evaluation based on the symptoms reported. Of this group, 90 persons agreed to undergo physical examination (71.4%; 46 B27 positive, 44 B27 negative). There was no difference between the B27-positive and -negative groups in terms of age (mean +/- SD 38.4 +/- 10 versus 39.5 +/- 11 years) and sex ratio (67% versus 68% were men). In addition, 58 donors (32 B27 positive, 26 B27 negative) agreed to undergo magnetic resonance imaging (MRI) of the sacroiliac joints. A diagnosis of SpA and ankylosing spondylitis (AS) was made according to the European Spondylarthropathy Study Group criteria and the New York criteria.

RESULTS

SpA was diagnosed in 20 persons: 19 of 140 B27-positive (13.6%) and 1 of 133 B27-negative (0.7%) subjects (15 male and 5 female). AS was diagnosed in 9 persons (7 male and 2 female; 45%), undifferentiated SpA (USpA) in 7 (5 male and 2 female; 35%), psoriatic arthritis (PsA) in 3 (2 male and 1 female; 15%), and chronic reactive arthritis (ReA; Reiter's syndrome) in 1 (male; 5%). On the basis of a B27 frequency of 9.3% among the population of Berlin (3.47 million persons), the estimated prevalence of SpA was 1.9%, AS was 0.86%, USpA was 0.67%, and PsA was 0.29%. The relative risk of developing SpA in B27-positive subjects was calculated as 20.7 (95% confidence interval 4.6-94.2; P = 0.001). Of 58 persons with IBP, sacroiliitis was detected by MRI in 15 of 32 B27-positive (46.9%) and 1 of 26 B27-negative (3.9%) subjects (P = 0.002). Four of these 16 donors did not fulfill diagnostic criteria for SpA.

CONCLUSION

With a calculated prevalence of 1.9%, spondylarthropathies are among the most frequent rheumatic diseases in the white population. HLA-B27 positive persons carry a 20-fold increased risk of developing SpA. AS and USpA are the most frequent SpA subtypes. Persons with IBP who are B27 positive have a 50% likelihood of having sacroiliitis.

High frequency of Yersinia antibodies in healthy populations in Finland and Germany

Sera from 94 healthy Finnish and 100 healthy German blood donors were studied for Yersinia enterocolitica antibodies by two different techniques, enzyme immunoassay and immunoblotting, to compare the frequency of Yersinia infections in Finnish and German populations. The prevalence of Yersinia antibodies in Finland (19% and 31% by enzyme immunoassay and immunoblotting, respectively) and in Germany (33%, 43%) is relatively high and may indicate many subclinical Yersinia infections in healthy populations. Postinfectious complications, such as reactive arthritis, may follow also such subclinical infection; sensitive serological tests are important in their diagnosis.

HLA-B27 and bacteria

Most HLA-B27 positive individuals live without noticing the risk factor they carry. Only when certain bacteria come into play, usually in the form of intestinal or genital infection, some of the HLA-B27 positive individuals will develop a reactive disease. Such an association is so well established that it has formed a basis to study the relation of autoimmune reactions to microbial infections. Early epidemiological investigations have been followed by studies on immunological cross-reactivity and recently by studies on presentation of bacterial peptides by the HLA-B27 molecule. This introductory review briefly summarizes the evolution of the research, the goal of which still remains to clarify the etiopathogenetic mechanisms of HLA-B27 associated diseases.