IgG and IgA immune response against klebsiella in HLA-B27-associated anterior uveitis

Environmental Risks for Spondyloarthropathies

Spondyloarthropathies, also known as spondyloarthritis, encompasses a spectrum of diseases classified by it's axial and peripheral musculoskeletal manifestations. Extra-articular features are common in SpA making these systemic rheumatologic diseases involve the skin, eye, gut, and other organ systems.Research has identified risk factors for the development of spondyloarthritis, particularly regarding genetic susceptibility and the strong association with HLA-B27. Multiple studies have elucidated clinical risk factors associated with SpA disease activity and severity. In this review, we aim to explore the environmental risk factors for spondyloarthritis.

Association between Klebsiella pneumoniae and ankylosing spondylitis: A systematic review and meta-analysis

AIM

The aim of this study is to evaluate the association between Klebsiella pneumoniae infection and ankylosing spondylitis (AS).

METHOD

Five electronic databases, PubMed, Embase, Medline, Web of Science, and Scopes, were searched until September 29, 2021. Cohort and case-control studies that assessed the association between K. pneumoniae infection and AS were included. Pooled odds ratio (OR) was selected to show the effect size. Subgroup analysis (active or inactive AS) and 2 forms of sensitivity analysis were conducted. All statistical analyses were conducted by using STATA 12.0.

RESULTS

There were 25 case-control studies finally included, including 8 studies concerning presence of K. pneumoniae in feces, and 17 studies concerning serum antibody (immunoglobulin [Ig]G, IgM, IgA) against K. pneumoniae. The results suggested that when compared with healthy people, presence of K. pneumoniae in feces was associated with AS (OR: 5.65; 95% CI: 1.68-19.00). Similarly, when compared with healthy people, higher positive rates of IgA (OR: 6.28; 95% CI: 3.32-11.91) and IgG (OR: 5.22; 95% CI: 1.36-19.99) were observed. Subgroup analyses suggested that association between K. pneumoniae and AS appears stronger in active AS.

CONCLUSION

When compared with healthy people, a significantly higher positive rate of K. pneumoniae in feces, serum IgA and IgG were observed in patients with AS, suggesting that K. pneumoniae probably plays a crucial role in the occurrence of AS. The findings in this study need further prospective investigations for confirmation.

Ankylosing spondylitis risk factors: a systematic literature review

Radiographic axial spondyloarthritis (also known as ankylosing spondylitis [AS]) is a chronic immune-mediated arthritis characterized by inflammation of the axial skeleton, peripheral joints, and entheses. It is estimated that 1 in every 200 people are affected by AS, making it an important healthcare and socioeconomic issue. In this review, we aim to explore the current understanding of AS risk factors and provide a comprehensive update. Multiple search strings were used to identify articles of interest published in PubMed between January 1, 2013, and February 1, 2021. On the basis of the literature review and analysis, we present up-to-date information on the risk factors of developing AS and our viewpoints on disease onset and progression. Multiple genetic and nongenetic risk factors have been suggested in the onset of AS. HLA-B27 is known to have a strong association with the disease, but other genes have been implicated in disease development. Aside from genetics, other factors are thought to be involved; up to 70% of patients with AS have subclinical intestinal inflammation, suggesting that the origin of the disease may be in the gut. The exact mechanism by which AS onset begins is most likely complex and multifactorial. Key Points • It remains unclear how interactions between genes, microbes, mechanical stress, gender, and other environmental and lifestyle factors predispose patients to the development of ankylosing spondylitis (AS). • The exact mechanisms of AS are complex and multifactorial which will require much future research • Recognizing the risk factors, as well as understanding gene-environment interactions, may offer valuable insights into the etiology of AS and have important implications for diagnosis and treatment strategies.

Ankylosing spondylitis is linked to Klebsiella--the evidence

Ankylosing spondylitis (AS) is a chronic inflammatory spinal and large-joint arthritic and potentially disabling condition, mainly affecting males of young age groups. Extensive literature based on the results of various genetic, microbiological, molecular and immunological studies carried out by independent research groups suggests that Klebsiella pneumoniae is the main microbial agent being implicated as a triggering and/or perpetuating factor in the etiopathogenesis of AS. Novel diagnostic markers and criteria based on the association with high anti-Klebsiella antibodies could be used in the detection of AS patients during early stages of the disease, and together with the current treatments might help in implementing the use of new therapeutic anti-microbial measures in the management of AS. Prospective longitudinal studies with the use of anti-microbial measures in patients with AS are required to establish the therapeutic benefit of this microbe-disease association.

Acute anterior uveitis and HLA-B27

Acute anterior uveitis is the most common form of uveitis. HLA-B27-associated acute anterior uveitis is a distinct clinical entity that has wide-ranging medical significance due to its ocular, systemic, immunologic, and genetic features. The association between HLA-B27 and the spectrum of HLA-B27-associated inflammatory diseases remains one of the strongest HLA-disease associations known to date. This review examines acute anterior uveitis with particular focus on HLA-B27-associated acute anterior uveitis, including the epidemiology, immunopathology, association with HLA-B27 and its subtypes, clinical features, complications, prognosis, and potential new therapies such as anti-TNFalpha therapy and oral HLA-B27-peptide tolerance. There have been substantial recent advances in both clinical and basic scientific research in this field, including studies of the various animal models of acute anterior uveitis and the HLA-B27 transgenic animals, and these are summarized in this review. To the ophthalmologist, HLA-B27-associated acute anterior uveitis is an important clinical entity that is common, afflicts relatively young patients in their most productive years, and is associated with significant ocular morbidity due to its typically recurrent attacks of inflammation and its potentially vision-threatening ocular complications. Furthermore, to the ophthalmologist and the internist, HLA-B27-associated acute anterior uveitis is also of systemic importance due to its significant association with extraocular inflammatory diseases.

Autoantibodies specificity in acute anterior uveitis according to the presence of the HLA-B27 allele

PURPOSE

To study HLA-B27(+) and HLA-B27(-) patients with AAU with respect to the frequency and specificity of organ-specific and non-organ-specific autoantibodies.

METHODS

Fifty-seven consecutive patients with AAU were subjected to ophthalmologic and rheumatologic evaluation as well as to autoantibody determination: antinuclear antibodies (ANA), rheumatoid factor (RF), anticardiolipin, anti-smooth muscle, and anti-parietal cell antibodies, and immunoblot for antibodies to HeLa cells and to bovine iris extract. HLA-B27 was determined by a microlymphocytotoxicity assay. Statistical analysis employed chi-square test, Fisher's exact test, and McNemar test.

RESULTS

Thirty-four patients had the HLA-B27 allele (B27(+)/AAU) and 23 did not (B27(-)/AAU). ANA, RF, anticardiolipin, and anti-parietal cell antibodies appeared in low frequency. No patient presented anti-smooth muscle antibody. Immunoblot showed a high frequency of antibodies to HeLa cell proteins in B27(-)/AAU patients with predominant reactivity at 46 kDa and 56 kDa. In contrast, sera from B27(+)/AAU patients reacted poorly against HeLa cell antigens. Immunoblot with bovine iris extract showed a significant frequency of antibodies in both groups, with a predominant response to antigens with an estimated mobility of 35, 52, and 54 kDa.

CONCLUSION

Antibodies specific to iris antigens were equally frequent in both acute uveitis groups, whereas non-organ-specific autoantibodies, especially those to HeLa cell proteins, were far less frequent in B27(+)/AAU than in B27(-)/AAU patients.

Humoral immune response to Klebsiella capsular polysaccharides in HLA-B27-positive patients with acute anterior uveitis and ankylosing spondylitis

Klebsiella is suggested to trigger ankylosing spondylitis (AS) and acute anterior uveitis (AAU) in HLA-B27-positive individuals. Previous investigations showed an increased antibody response to the Klebsiella capsular types K26, K36, and K50 in sera from HLA-B27-positive AS patients. In the present study the prevalence and titers of antibodies against Klebsiella capsular antigens were measured by means of an ELISA in 32 sera from HLA-B27-positive AAU patients either with (n = 10) or without AS (n = 22) and compared with sera from HLA-B27-negative AS-patients (n = 13). Sera from either HLA-B27-positive (n = 45) or negative (n = 40) healthy individuals served as control. Sera from HLA-B27-positive AAU with or without AS showed significantly higher antibody prevalence and IgG-titers against capsular antigens of the Klebsiella serotypes K26, K36, and K50 when compared with sera from HLA-B27-negative AS patients or with healthy controls. These results might be taken to indicate the predominance of these serotypes in the HLA-B27-associated AS and AAU.

Etiology and clinical features of anterior uveitis in southern croatia (dalmatia)

Patients with endogenous uveitis represent 6.5+ of patients in University Hospital Split, which serves most of South Croatia. Within a four-year period 208 patients were treated for endogenous uveitis. Results of clinical-laboratory examinations and treatment of 112 subjects suffering from anterior uveitis are presented and compared. Acute anterior uveitis (AAU) was the commonest form of uveal inflammation. It was present in 49+ of all uveitis cases and in 91.1+ of all anterior uveitis cases (AU). 67.6+ of the subjects with AAU had and 32.4+ did not have the HLA B(27) antigen. The inflammatory pattern in B(27)(+) patients was typical of B(27)(+) AAU. Patients with B(27)(+) AAU exhibited the same inflammatory pattern as those with B(7)(+) AAU. B(27)(+) AAU patients had significantly more systemic/rheumatic diseases (p>0.05), while patients with B(27)(-) AAU had significantly more infectious diseases (p>0.05). Forty percent of the patients with chronic anterior uveitis suffered from juvenile rheumatoid arthritis. The authors observed the rise in peripheral blood IgG, IgA, IgM, CD(2)(+), CD(4)(+) and B cells during the acute phase of AAU. Normalization of B cells (CD(20)(+)) was observed in early remission of anterior uveitis, about eight weeks after the onset of the disease.

Acute anterior uveitis: clinical and experimental aspects

Acute anterior uveitis (AAU) or iritis is an inflammatory disorder of the anterior structures of the eye that may be associated with a number of disease entities. A significant proportion of patients will have no evidence of an underlying disorder and are labeled as idiopathic. Within this group approximately 50% will possess the human leukocyte antigen, HLA-B27, and some will have an associated spondyloarthropathy such as ankylosing spondylitis or Reiter's syndrome. Nevertheless, a number of HLA-B27-positive patients have no apparent underlying rheumatic disorder. The potential interplay of HLA-B27 and certain infective agents in the pathogenesis of AAU is discussed with particular reference to Yersinia species. Presentation of a uveitogenic peptide, similar to the arthritogenic peptide model in spondyloarthropathies, may be a mechanism involved in the development of AAU. Experimental models in animals have increased our understanding of the roles of retinal proteins and bacterial peptides, as well as T cells and cytokines, in the pathogenesis of uveitis. As in animal models of arthritis, certain retinal peptides (in conjunction with adjuvant therapy) can induce uveitis in animals. The treatment of isolated AAU usually involves topical medication and the prognosis is good. Occasional cases, especially those associated with systemic disorders, may require the addition of systemic corticosteroids or other immunosuppressive medications.