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.

Studying patients with inflammatory back pain and arthritis of the lower limbs clinically and by magnetic resonance imaging: many, but not all patients with sacroiliitis have spondyloarthropathy

OBJECTIVE

Clinical and magnetic resonance imaging (MRI) data of 170 consecutive patients with inflammatory back pain (IBP) and/or oligoarthritis of the lower limbs were evaluated in a retrospective study. The aim was to determine the frequency of sacroiliitis and spondyloarthropathy (SpA) in this population, and to assess the significance of HLA B27 measurements for diagnosis in early disease.

METHODS

Pelvic X-rays were performed in all IBP patients and dynamic MRI of the sacroiliac joints in patients with IBP who had indefinite results on sacroiliac X-rays (n = 32).

RESULTS

European Spondyloarthropathy Study Group criteria for SpA were fulfilled by 106/170 patients (62.4%); eight additional patients had symptoms suggestive of SpA (4.7%). The most frequent SpA subset was undifferentiated SpA (uSpA), diagnosed in 46/106 patients (43.4%). Sacroiliitis was detected by MRI in 21/32 patients with IBP and unclear X-rays (65.6%). Of those, 14 were diagnosed as SpA and seven females with moderate unilateral sacroiliitis, but no features of SpA, also not on follow-up (at least 1 yr), were classified as undifferentiated sacroiliitis (US). Ten of the 14 SpA (71.4%) and none of the seven US patients were HLA B27 positive.

CONCLUSION

HLA B27 positivity in IBP patients with MRI-proven sacroiliitis positively predicts SpA. uSpA is a frequent SpA subset. There are HLA B27-negative non-SpA patients with moderate unilateral sacroiliitis whom we propose to be classified as US.

[The diagnostic significance of immunogenetic markers in vertebrogenic neurological syndromes]

A total of 116 patients presenting with different neurological syndromes of vertebral osteochondrosis were examined. More common in patients with reflex neurological manifestations of osteochondrosis compared with controls (n = 51) was a complete HLA phenotype (heterozygosity) determining better evolutional and biological resistance to injuring factors and ability to produce adequate adaptive and compensatory reactions. The diagnosing of incomplete phenotype in other groups indicated homozygosity of genes and suggested a high risk for development of the disorder. Criteria have been established for a relative risk of development of the disease for all six vertebrogenic neurological syndromes.

Evidence that HLA-B*2706 is not protective against spondyloarthropathy

OBJECTIVE

Studies in Southeast Asia showed that HLA-B*2704 is positively associated with spondyloarthropathy (SpA), while B*2706 does not occur in such patients. In view of the absence of an association between B*2706 and SpA it was suggested that B*2706 protects against the disease, while it is supposed that B*2704 presents pathogenetic peptides. We studied families in which both B*2704 and B*2706 occurred to see whether in B*2704/B*2706 heterozygotes the effect of one of the subtypes shows a preponderance over the other.

METHODS

Two families of mixed Chinese/Indonesian origin were studied. HLA-B27 subtyping was performed by polymerase chain reaction in combination with sequence specific oligonucleotide probes.

RESULTS

In one family, members with B*2704, B*2706, or both occurred. In the other family B*2704, B*2706, and B*2708 were present. In both families SpA was seen only in B*2704 positive members, while the B*2706 and B*2708 positive members were healthy, except some B*2704/B*2706 or B*2704/B2708 heterozygotes.

CONCLUSION

The pathogenic influence of B*2704 is thus dominant over the supposed protective influence of B*2706. It is probable that B*2704 can present pathogenetic peptides, while a protective influence of B*2706 does not exist. B*2708, which was until now described in only a few cases, behaved in this study as B*2706 and is probably not associated with SpA.

Inflammatory disease in HLA-B27 transgenic rats

A spontaneous inflammatory disease in rats transgenic for HLA-B27 resembles the B27-associated human spondyloarthropathies. Colitis and arthritis, the two most important features, require T cells, gut bacteria, and high expression of B27 in bone marrow-derived cells. Control rats with HLA-B7 remain healthy. Most rats with HLA-Cw6 (associated with psoriasis vulgaris) remain healthy; a minority develop mild and transient disease. Rats with a mutant B27 with a Cys67-->Ser substitution resemble wild-type B27 transgenics, but with a lower prevalence of arthritis. A similar phenotype is seen in B27 rats co-expressing a viral peptide that binds B27. Disease-prone LEW but not F344 B27 rats develop high serum IgA levels concurrent with disease progression. Colitis is associated with high interferon-gamma, arthritis with high interleukin-6. Disease is similar in B27 LEW, F344, and PVG rats, but the DA background is protective.

CONCLUSIONS

The spondyloarthropathy-like disease in rats is specific for HLA-B27 but does not require Cys67. Arthritis but not colitis is particularly sensitive to B27 peptide-binding specificity. Genetic background exerts a strong influence, but some phenotypic differences exist between permissive strains that do not influence disease susceptibility. The data favor a role for B27 peptide presentation in arthritis, but other mechanisms to explain the role of B27 have not been excluded.

Two color analysis of HLA-B27 antigen by flow cytometer--a comparative study by conventional microlymphocytotoxicity, DNA genotyping polymerase chain reaction and flow cytometric measurement

For evaluation of specificity and sensitivity of flowcytometric determination of HLA-B27 antigen, we determined the HLA-B27 on lymphocytes using HLA-B27 monoclonal antibody by flow cytometer. Data were compared to those by conventional Terasaki microlymphocytoxicity test and DNA genotyping Polymerase Chain Reaction (PCR) method. One hundred and ninety four patients with various forms of arthritis were included in this study. Forty one of them were HLA-B27 positive, confirmed by three methods concomitantly with complete accordance. None of serological B27 negative, B7 CREG positive cells were found to be flowcytometric fluorescence positive. Furthermore, there was no significant difference of B27 intensity between different B27 DNA subtypes, nor was there any difference between primary ankylosing spondylitis (AS) and other secondary spondylitis patients as measured by mean channel of fluorescence. It is suggested that flowcytometric measurement of HLA-B27 antigen is a rapid and reliable method for HLA-B27 determination.

Nuclear factor-kappa B activity in T cells from patients with rheumatic diseases: a preliminary report

OBJECTIVE

The NF-kappa B/Rel family of transcription factors regulates the expression of many genes involved in the immune or inflammatory response at the transcriptional level. The aim of this study was to determine whether distinctive patterns of NF-kappa B activation are seen in different forms of joint disease.

METHODS

The DNA binding activity of these nucleoproteins was examined in purified synovial and peripheral T cells from patients with various chronic rheumatic diseases (12: four with rheumatoid arthritis; five with spondyloarthropathies; and three with osteoarthritis).

RESULTS

Electrophoretic mobility shift assays disclosed two specific complexes bound to a NF-kappa B specific 32P-labelled oligonucleotide in nucleoproteins extracted from purified T cells isolated from synovial fluid and peripheral blood of patients with rheumatoid arthritis. The complexes consisted of p50/p50 homodimers and p50/p65 heterodimers. Increased NF-kappa B binding to DNA in synovial T cells was observed relative to peripheral T cells. In non-rheumatoid arthritis, binding of NF-kappa B in synovial T cells was exclusively mediated by p50/p50 homodimers.

CONCLUSION

Overall, the results suggest that NF-kappa B may play a central part in the activation of infiltrating T cells in chronic rheumatoid arthritis. The activation of this nuclear factor is qualitatively different in rheumatoid synovial T cells to that in other forms of non-rheumatoid arthritis (for example, osteoarthritis, spondyloarthropathies).

HLA-B27 and the seronegative spondyloarthropathies

In the 25 years since the initial reports of the association of HLA-B27 with ankylosing spondylitis (AS) and subsequently with Reiter's syndrome, psoriatic spondylitis, and the spondylitis of inflammatory bowel disease, the association of HLA-B27 with the seronegative spondyloarthropathies has remained one of the best examples of a disease association with a hereditary marker. HLA-B27 has been recognized as representative of a spectrum of diseases, ranging from the majority of HLA-B27-positive individuals who have no disease at all, through those with isolated eye or skin involvement, to those with critical eye, heart, and peripheral joint compromise of full-blown AS. Yet HLA polymorphism has evolved in response to environmental stresses, and even the presence of HLA-B27 itself appears to confer advantages in certain infectious diseases, such as acquired immune deficiency syndrome (AIDS). This article will review what is currently known about HLA-B27 and disease, especially in the seronegative spondyloarthropathies. The structure-function relationship of HLA-B27 will be presented, including differences between the B27 subtypes both in their ethnic variation and possible disease implications. The disease spectrum conferred by the presence of HLA-B27 will also be discussed, and the theories of how HLA-B27 contributes to the pathogenesis of the spondyloarthropathies will be considered.

Contrasting cytokine profiles in the synovium of different forms of juvenile rheumatoid arthritis and juvenile spondyloarthropathy: prominence of interleukin 4 in restricted disease

OBJECTIVE

To determine the pattern of expression of Type 1 and Type 2 cytokines in synovial tissues and fluids (SF) of patients with different forms of juvenile rheumatoid arthritis (JRA) and juvenile spondyloarthropathy (JSpA), and to contrast these with findings in adult patients with RA.

METHODS

Sixty-three SF mononuclear cell preparations and synovial tissue samples from 50 patients with JRA or JSpA and 7 synovial tissues from patients with adult onset RA were analyzed by reverse transcription polymerase chain reaction for the presence or absence of interleukin 2 (IL-2), tumor necrosis factor-beta (TNF-beta), interferon-gamma (IFN-gamma), and IL-10 and IL-4 mRNA.

RESULTS

IL-4 mRNA was identified significantly more often in the synovial compartment of patients with pauciarticular onset disease (JRA or JSpA) compared with polyarticular onset JRA (58 vs 14%; p < 0.01) or RA (29%). Similarly, IL-4 mRNA was detected more often in those with a persistently pauciarticular disease course compared to those with a polyarticular course (68 vs 30%; p < 0.01). Furthermore, the combination of IL-4 and IL-10 mRNA was found more frequently in nonerosive compared with erosive disease (38 vs 15%; p < 0.05). IL-2 and TNF-beta mRNA were found in all groups. IFN-gamma mRNA was detected in 33% of those with systemic onset JRA compared with 85% of other types of JRA (p < 0.01).

CONCLUSION

This study provides further evidence of immunopathological differences between chronic forms of arthritis with childhood onset, and highlights similarities with and differences from adult RA. Our findings suggest that IL-4, possibly in combination with IL-10, has an antiinflammatory or disease restricting role.

Tuberculous spondylitis as a cause of inflammatory spinal pain: a report of 4 cases

Patients are said to have inflammatory spinal pain if they fulfill at presentation 4 of the following 5 criteria: duration of spinal discomfort for at least 3 months, spinal morning stiffness, age less than 40, insidious onset of symptoms, and no relief from pain with rest, but improvement with exercise. Inflammatory spinal pain is typical of the spondylarthropathies. Only in a minority of the cases it is found in other rheumatic disorders such as rheumatoid arthritis, fibromyalgia or infectious spondyilitis. Tuberculous spondylitis is rarely mentioned as a possible cause of inflammatory spinal pain. We describe 4 patients with tuberculous spondylitis seen over a 3-year period who met the clinical criteria for inflammatory spinal pain at presentation. We conclude that inflammatory spinal pain may be a presenting feature, albeit rare, of tuberculous spondylitis. Awareness of this finding should help facilitate the proper diagnosis and the institution of appropriate therapy.

Routine molecular genotyping of HLA-B27 in spondyloarthropathies overcomes the obstacles of serological typing and reveals an increased B *2702 frequency in ankylosing spondylitis

OBJECTIVE

To evaluate the reproducibility and reliability of polymerase chain reaction (PCR) in HLA-B27 typing compared to the conventionally used microlymphocytotoxicity test (MLCT). To determine the HLA-B27 subtype frequencies (B*2701-B*2709) in patients with HLA-B27 associated disease and healthy persons using sequence specific oligonucleotides (SSO).

METHODS

398 consecutive patients were HLA-B27 typed by MLCT and PCR. Subtyping by SSO was performed in 142 patients with HLA-B27 associated disease [ankylosing spondylitis (AS) n = 38, reactive arthritis 44, undifferentiated spondyloarthropathy (uSpA) 45, psoriatic arthritis 15] and 125 healthy HLA-B27 controls.

RESULTS

MLCT identified 61 HLA-B27 positive patients (15.3%); PCR identified 78 positive patients (19.6%). MLCT gave false negative results for 8 patients (2.0%) and false positives for a further 7 (1.8%). Only subtypes B*2702 and B*2705 were present in patients and controls. Overall frequencies of B*2702 in patients and controls were 14.1 and 9.6%, respectively. The B*2702 frequency was significantly (pcorr. < 0.04) higher in AS (23.7%) and lower in uSpA (6.7%) patients.

CONCLUSION

HLA-B27 typing by PCR is reliable and reproducible and therefore recommended for routine typing. It overcomes the obstacles of serological typing, i.e., equivocal results and cross-reactivity. In addition, subtype frequencies (B*2702 and B*2705) are equally distributed among patients and controls, although subtype B*2702 seems to be more frequent in AS and less so in uSpA.

The seronegative spondyloarthropathies

The four seronegative spondyloarthropathies can be divided into two main groups by their pattern of sacroiliitis and spondylitis (Table 1). The axial skeletal changes of ankylosing spondylitis and enteropathic arthropathy are often indistinguishable, as are those of psoriatic arthritis and Reiter's syndrome. Early proximal appendicular joint involvement in ankylosing spondylitis is a poor prognostic sign except in women where peripheral arthritis is more common, but has a more benign course. Peripheral joint destruction in enteropathic arthropathy is rare because treatment of the bowel disease also treats the arthritis. Distal appendicular involvement is characteristic of psoriatic arthritis and Reiter's syndrome. Proliferative erosions and enthesitis, periostitis, and normal mineralization aid in differentiating psoriatic arthritis and Reiter's syndrome from rheumatoid arthritis. The distribution of arthritis also differs from that seen in classic rheumatoid arthritis, with asymmetry and involvement of the distal interphalangeal joints more common in psoriatic disease and Reiter's syndrome.

Psoriatic spondyloarthropathy with secondary amyloidosis

We report an HLA-B27 positive patient with severe psoriatic spondyloarthropathy who developed secondary reactive amyloidosis. The clinical course was characterized by progressive renal failure with nephrotic syndrome and cardiac dysfunction. He died suddenly and autopsy revealed diffuse amyloid deposits in the heart, kidneys, and many other organs. Amyloid deposits were present in the cardiac conduction system including the sinoatrial and atrioventricular nodes, myocardial interstitium, and intramyocardial small blood vessels. The severe AA amyloid deposit in the heart with involvement of conduction system is unusual, and has not been described in patients with psoriasis or psoriatic arthritis.

Immunity to the G1 globular domain of the cartilage proteoglycan aggrecan can induce inflammatory erosive polyarthritis and spondylitis in BALB/c mice but immunity to G1 is inhibited by covalently bound keratan sulfate in vitro and in vivo

Earlier work from this laboratory showed that the human proteoglycan aggrecan from fetal cartilages can induce a CD4+ T cell-dependent inflammatory polyarthritis in BALB/c mice when injected after removal of chondroitin sulfate chains. Adult keratan sulfate (KS)-rich aggrecan does not possess this property. We found that two CD4+ T cell hybridomas (TH5 and TH14) isolated from arthritic mice recognize bovine calf aggrecan and the purified G1 domain of this molecule, which also contains a portion of the interglobular domain to which KS is bound. These hybridoma responses to G1 are enhanced by partial removal of KS by the endoglycosidase keratanase or by cyanogen bromide cleavage of core protein. KS removal results in increased cellular uptake by antigen-present cells in vitro. After removal of KS by keratanase, G1 alone can induce a severe erosive polyarthritis and spondylitis in BALB/c mice identifying it as an arthritogenic domain of aggrecan. The presence of KS prevents induction of arthritis presumably as a result of an impaired immune response as observed in vitro. These observations not only identify the arthritogenic properties of G1 but they also point to the importance of glycosylation and proteolysis in determining the arthritogenicity of aggrecan and fragments thereof.

Seronegative spondyloarthropathies and HLA-B27 subtyes: a study in Asian Indians

In this study, 60 HLA-B27+ve SSA patients and 17 healthy controls belonging to North India were analyzed to ascertain heterogeneity of the B27 molecule in this population. ID-IEF and PCR-SSOP technologies were used to analyze polymorphism in exon 2 and 3 of the HLA-B27 gene. Four different subtypes were encountered: B*2702,04,05 and 07. Other subtypes of B27 viz B*2701,03,06 and 08 were not encountered. B*2704 (common oriental subtype) and B*2705 (common Caucasian subtype) were the most common subtypes in the control and patient groups. B*2707 was less frequently encountered in both groups and B*2702 was found in only one AAU patient. B*2704 was the predominant subtype in the AS group (70.8%) compared to its frequency of 47% in healthy controls (RR = 2.73) while in the undiff SpA group, B*2705 occurred most frequently (73.1%, RR = 3.05). B27 subtypes segregated differently in males and females. 12 of the 17 male AS patients carried B*2704 as compared to 1 of 8 healthy males (X2 = 3.9, P < 0.05). On the other hand, in the undiff SpA, B*2705 was significantly raised in female patients (100%) as compared to healthy females (22.2%, X2 = 4.9, P < 0.05). Subtype distribution is indicative of racial admixture in the Asian Indian population.

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.