Diagnositic value of pelvic enthesitis on MRI of the sacroiliac joints in enthesitis related arthritis.

BACKGROUND: To determine the prevalence and diagnostic value of pelvic enthesitis on MRI of the sacroiliac (SI) joints in enthesitis related arthritis (ERA). METHODS: We retrospectively studied 143 patients aged 6-18 years old who underwent MRI of the SI joints for clinically suspected sacroiliitis between 2006-2014. Patients were diagnosed with ERA according to the International League of Associations for Rheumatology (ILAR) criteria. All MRI studies were reassessed for the presence of pelvic enthesitis, which was correlated to the presence of sacroiliitis on MRI and to the final clinical diagnosis. The added value for detection of pelvic enthesitis and fulfilment of criteria for the diagnosis of ERA was studied. RESULTS: Pelvic enthesitis was seen in 23 of 143 (16 %) patients. The most commonly affected sites were the entheses around the hip (35 % of affected entheses) and the retroarticular interosseous ligaments (32 % of affected entheses). MRI showed pelvic enthesitis in 21 % of patients with ERA and in 13 % of patients without ERA. Pelvic enthesitis was seen on MRI in 7/51 (14 %) patients with clinically evident enthesitis, and 16/92 (17 %) patients without clinically evident enthesitis. In 7 of 11 ERA-negative patients without clinical enthesitis but with pelvic enthesitis on MRI, the ILAR criteria could have been fulfilled, if pelvic enthesitis on MRI was included in the criteria. There is a high correlation between pelvic enthesitis and sacroiliitis, with sacroiliitis present in 17/23 (74 %) patients with pelvic enthesitis. CONCLUSIONS: Pelvic enthesitis may be present in children with or without clinically evident peripheral enthesitis. There is a high correlation between pelvic enthesitis and sacroiliitis on MRI of the sacroiliac joints in children. As pelvic enthesitis indicates active inflammation, it may play a role in assessment of the inflammatory status. Therefore, it should be carefully sought and noted by radiologists examining MRI of the sacroiliac joints in children.

Diagnostic value of MRI features of sacroiliitis in juvenile spondyloarthritis.

AIM: To determine the diagnostic utility of magnetic resonance imaging (MRI) features of sacroiliitis in juvenile spondyloarthritis (JSpA). MATERIALS AND METHODS: This was a prospective study of 80 paediatric patients who underwent MRI of the sacroiliac joints that were clinically suspected to have sacroiliitis. The prevalence of MRI features of active and structural lesions of sacroiliitis was recorded. Patients were classified according to the International League of Association for Rheumatology criteria. The MRI findings were compared to the final clinical diagnosis. RESULTS: Sacroiliitis was seen in 25/80 (31%) patients. MRI showed active inflammation in 23 patients (29%): synovial enhancement (28%), high short tau inversion recovery (STIR)-signal in the joint space (29%), bone marrow oedema (BMO; 20%), and capsulitis (8%). Structural changes were present in 14 patients (18%): erosion (14%), fat infiltration (13%), sclerosis (8%), and ankylosis (1%). Of all MRI features, ankylosis (100%), capsulitis (98%), BMO (96%), and erosion (96%) had the highest specificity for JSpA; global diagnostic impression (55%) and synovial enhancement (52%) were the MRI features with the highest sensitivity. The likelihood ratios (LR+) for diagnosis of JSpA were high for BMO (10.5), capsulitis (7.5), global diagnostic impression (6.9), and erosions (6.75), but greater for BMO concomitant with synovial enhancement (LR+ 19.5) and for erosion concomitant with BMO (LR+ 12) or synovial enhancement (LR+ 13.5). CONCLUSION: There are multiple features of active inflammation and structural damage visible at MRI of the sacroiliac joints that can provide a specific diagnosis of JSpA when present in children with suspected sacroiliitis. Synovial enhancement is the MRI feature with the highest sensitivity for JSpA. If BMO is seen concomitant with synovial enhancement or erosion, the diagnosis of JSpA is very likely. Ankylosis, capsulitis, bone marrow oedema, and erosion all have a high specificity for JSpA. Absence of MRI findings of sacroiliitis does not exclude the diagnosis of JSpA.

Methotrexate in combination with other DMARDs is not superior to methotrexate alone for remission induction with moderate-to-high-dose glucocorticoid bridging in early rheumatoid arthritis after 16†weeks of treatment: the CareRA trial.

OBJECTIVES: To compare the efficacy and safety of intensive combination strategies with glucocorticoids (GCs) in the first 16 weeks (W) of early rheumatoid arthritis (eRA) treatment, focusing on high-risk patients, in the Care in early RA trial. METHODS: 400 disease-modifying antirheumatic drugs (DMARD)-naive patients with eRA were recruited and stratified into high risk or low risk according to classical prognostic markers. High-risk patients (n=290) were randomised to 1/3 treatment strategies: combination therapy for early rheumatoid arthritis (COBRA) Classic (methotrexate (MTX)+ sulfasalazine+60 mg prednisone tapered to 7.5 mg daily from W7), COBRA Slim (MTX+30 mg prednisone tapered to 5 mg from W6) and COBRA Avant-Garde (MTX+leflunomide+30 mg prednisone tapered to 5 mg from W6). Treatment modifications to target low-disease activity were mandatory from W8, if desirable and feasible according to the rheumatologist. The primary outcome was remission (28 joint disease activity score calculated with C-reactive protein <2.6) at W16 (intention-to-treat analysis). Secondary endpoints were good European League Against Rheumatism response, clinically meaningful health assessment questionnaire (HAQ) response and HAQ equal to zero. Adverse events (AEs) were registered. RESULTS: Data from 98 Classic, 98 Slim and 94 Avant-Garde patients were analysed. At W16, remission was reached in 70.4% Classic, 73.6% Slim and 68.1% Avant-Garde patients (p=0.713). Likewise, no significant differences were shown in other secondary endpoints. However, therapy-related AEs were reported in 61.2% of Classic, in 46.9% of Slim and in 69.1% of Avant-Garde patients (p=0.006). CONCLUSIONS: For high-risk eRA, MTX associated with a moderate step-down dose of GCs was as effective in inducing remission at W16 as DMARD combination therapies with moderate or high step-down GC doses and it showed a more favourable short-term safety profile. EUDRACT NUMBER: 2008-007225-39.

Sensitivity and specificity of criteria for spondyloarthritis in children with late onset pauciarticular juvenile chronic arthritis as well as their characteristics.

OBJECTIVE: To evaluate the sensitivity and specificity of criteria designed for spondyloarthritis in a university hospital treated population of children with late onset pauciarticular juvenile chronic arthritis and a control population. METHODS: Four sets of criteria especially designed for juvenile patients: Garmisch-Partenkirchen juvenile spondylitis criteria (= Garmisch), SEA (=seronegative enthesopathy and arthritis) syndrome, Enthesitis Related Arthritis (ERA), Atypical spondyloarthritis for children and two sets of criteria for patients without age specification (European spondyloarthropathy Study Group - ESSG and Amor) were evaluated in a cross-sectional way in a group of 43 consecutive patients with late onset pauciarticular juvenile chronic arthritis (LOPA) seen over a six-month period in the outpatient clinic. These criteria were analysed in 69 patients with other forms of juvenile chronic arthritis as well. The sensitivity and specificity were calculated for each set, as well as positive predictive value and likelihood ratio. The characteristics described in the different sets of criteria were separately evaluated in the LOPA patients and the other patients. RESULTS: For sensitivity, the Garmisch criteria scored the highest value (97.7%). However, sensitivity was significantly lower in two of the juvenile sets (SEA syndrome and Atypical spondyloarthritis), respectively 44.2% and 51.2%, as opposed to the other criteria (>85%; p<0.01 by Mc Nemar test). Specificity and positive predictive value (PPV) was the highest for the SEA syndrome criteria (98.5%, vs. 95.0%) followed by the ERA (95.6 % vs. 92.1 %) and the Garmisch criteria (94.2% vs. 91.3%). The positive likelihood ratio (LR+) was >10 in SEA (30.5), ERA (18.7) and Garmisch (16.8). The negative likelihood ratio (LR-) was <0.1 only in the Garmisch criteria (0.02). CONCLUSION: Sensitivity, specificity, PPV, LR+ and LR- for the Garmisch-Partenkirchen criteria suggest that they classify almost the same population as defined by LOPA. The SEA syndrome criteria, which were not designed to be classification criteria, being very specific, cannot be used in this patient population to classify a sufficient number of patients. The sensitivity and specificity for the ESSG criteria being similar in these children as in adults suggest they have similar characteristics. The Garmisch-Partenkirchen criteria and/or LOPA definition are major candidates for future research in identifying spondyloarthritis in juvenile patients.

Juvenile-onset systemic lupus erythematosus: different clinical and serological pattern than adult-onset systemic lupus erythematosus.

OBJECTIVE: To investigate differences in clinical signs and symptoms, and in antinuclear antibodies (ANA), between patients with juvenile-onset and adult-onset systemic lupus erythematosus (SLE). METHODS: Clinical and serological data of 56 patients with juvenile-onset SLE were compared with data of 194 patients with adult-onset SLE. ANA were determined by line immunoassay and by indirect immunofluorescence on Crithidia luciliae. RESULTS: Renal involvement, encephalopathy and haemolytic anaemia were seen, and anti-dsDNA, anti-ribosomal P and antihistone antibodies found, significantly more often in juvenile-onset SLE. Anti-dsDNA antibodies were directly associated, and anti-ribosomal P antibodies inversely associated, with renal involvement in juvenile-onset SLE. In juvenile patients with SLE and anti-dsDNA and without anti-ribosomal P antibodies the odds ratio for glomerulonephritis was 9.00; no patients with anti-ribosomal P but without anti-dsDNA had renal involvement. CONCLUSION: Patients with juvenile-onset SLE more often have renal involvement and encephalopathy than patients with adult-onset SLE. Anti-ribosomal P, anti-dsDNA and antihistone antibodies are more often found in patients with juvenile-onset SLE.

Expressive dimensions of pain catastrophizing: a comparative analysis of school children and children with clinical pain.

We investigated the role of the child's pain catastrophizing in explaining (1) children's self-reported tendency to verbally share their pain experience with others and (2) different dimensions of pain expression, as described by the mother and the father, including non-verbal and verbal communicative pain behaviour and protective pain behaviour. Participants were school children, children with chronic or recurrent pain, and their parents. The results showed that: (1) Pain catastrophizing was associated with children's greater self-acknowledged tendency to verbally share their pain experience with others. (2) Mothers and fathers perceived highly catastrophizing children to be more communicative about their pain. (3) The role of pain catastrophizing in the child's verbal sharing of pain experiences and in explaining expressive behaviour as rated by parents did not differ between the school children and children with recurrent and chronic pain. (4) Nevertheless, findings indicated marked differences between school children and the clinical sample. Children of the clinical sample experienced more severe pain, more pain catastrophizing, more protective pain behaviour, but less verbal communications about their pain. These results further corroborate the position that catastrophic thoughts about pain have interpersonal consequences. Findings are discussed in terms of the possible functions and effects upon others of pain catastrophizing and associated categories of pain behaviour.

Effect of age on prevalence of anticitrullinated protein/peptide antibodies in polyarticular juvenile idiopathic arthritis.

OBJECTIVES: Anticitrullinated protein/peptide antibodies (ACPA) have an excellent diagnostic performance for rheumatoid arthritis (RA). Despite similarities between RA and polyarticular juvenile idiopathic arthritis (JIA), the prevalence of ACPA in polyarticular JIA is low. We wanted to evaluate the influence of age, disease duration and total immunoglobulin G (IgG) concentration on ACPA positivity in this cohort. METHODS: Patients with JIA were classified according to age and International League of Associations for Rheumatology classification. Sixty-one JIA patients aged less than 16 yr were included and classified as polyarticular JIA (poly JIA <16; n=23) or non-polyarticular JIA (n=38). In addition, a group of 21 polyarticular JIA patients, aged more than 16 yr (poly JIA >16) and a group of 51 RA patients were included. Antibodies to the synthetic citrullinated peptides pepA and pepB were detected by line immunoassay and antibodies to cyclic citrullinated peptides (CCP2) by enzyme-linked immunosorbent assay. Serum IgG was measured by fixed-time immunonephelometry. RESULTS: No ACPA reactivity was observed in the non-polyarticular group. In poly JIA <16, only 1/23 had anti-CCP2 antibody, whereas in poly JIA >16 patients a significantly higher fraction was detected (6/21). All but one of the anti-CCP2 reactive patients were rheumatoid factor (RF) positive. Assessing anti-CCP2 antibody concentration as a continuous variable, significantly higher titres were found in poly JIA >16 compared with poly JIA <16. No correlation between anti-CCP2 concentration and total IgG was detected. Four patients demonstrated immunoreactivity against pepA and pepB; all of them were anti-CCP2 reactive, poly JIA >16 patients. CONCLUSIONS: ACPA are present in low prevalence in polyarticular JIA and are particularly found in the RF-positive subset. With age, a significant increase in anti-CCP2 positivity is observed in polyarticular JIA patients.

The Belgian-Flemish version of the Childhood Health Assessment Questionnaire (CHAQ) and the Child Health Questionnaire (CHQ).

We report herein the results of the cross-cultural adaptation and validation into the Belgian-Flemish language of the parent's version of two health related quality of life instruments. The Childhood Health Assessment Questionnaire (CHAQ) is a disease specific health instrument that measures functional ability in daily living activities in children with juvenile idiopathic arthritis (JIA). The Child Health Questionnaire (CHQ) is a generic health instrument designed to capture the physical and psychosocial well-being of children independently from the underlying disease. The Belgian-Flemish CHAQ was fully validated with 3 forward and 3 backward translations, while the Belgian-Flemish CHQ was equal to the Dutch version and revalidated in this study. The French version of both CHAQ and CHQ was exactly the same as the one used in France. A total of 199 subjects were enrolled: 53 patients with JIA (11% systemic onset, 40% polyarticular onset, 13% extended oligoarticular subtype, and 36% persistent oligoarticular subtype) and 146 healthy children. The CHAQ clinically discriminated between healthy subjects and JIA patients, with the polyarticular onset, and extended oligoarticular subtypes having a higher degree of disability, pain, and a lower overall well-being when compared to their healthy peers. Also the CHQ clinically discriminated between healthy subjects and JIA patients, with the polyarticular onset and extended oligoarticular subtypes having a lower physical and psychosocial well-being when compared to their healthy peers. In conclusion the Belgian-Flemish version of the CHAQ-CHQ is a reliable, and valid tool for the functional, physical and psychosocial assessment of children with JIA.

Occurrence of scleroderma in monozygotic twins.

Familial occurrence of scleroderma is rare and concordance for the disease in twins has been reported exceptionally. We describe 2 female identical twin pairs concordant for scleroderma. The first twin pair was diagnosed with the systemic form of scleroderma, the second pair with the localized form.

Favourable outcome in 135 children with juvenile systemic sclerosis: results of a multi-national survey.

OBJECTIVE: To increase the current knowledge of the outcome of juvenile systemic sclerosis (jSSc), which is currently limited. METHODS: In order to investigate the patient outcome and prognostic factors, starting October 1994, we distributed questionnaires to 324 paediatric rheumatology centres. RESULTS: Until 15 May 1998 responses from 46 centres were received, 34 of which returned completed questionnaires on a total of 135 patients. One hundred and twenty-two of the 135 patients were Caucasian, 100 were female. The mean age at disease onset was 8.8 yr (S.D. +/- 3.3 yr). The mean disease duration at the last follow-up was 5 yr(S.D. +/- 3.3 yr). At the last follow-up the disease was still active and required medication in 82 patients, 36 had inactive disease on medication, and 16 were in remission. Ninety per cent of the living patients were fully active in daily life at the last follow-up. Eight of the 135 patients had died. These patients had a median age at onset of the disease of 10.5 yr (range 6.7-15.8 yr). The median disease duration until death was 2 yr (range 1-8 yr). The causes of death were heart failure (five), renal failure (one), sepsis (one) and in one case the cause was not defined. The 1 yr survival rate was 99%, the 2 yr was 97% and the 4 yr was 95%. CONCLUSIONS: At a mean follow-up of 5 yr, the current results show a favourable outcome in most patients with childhood onset jSSc and a significantly better survival than in the adult SSc patients.

Premenopausal node-negative breast cancer: may adjuvant chemotherapy be indicated by the analysis of nuclear DNA dynamics?

The management of premenopausal node-negative breast cancer patients is discussed controversially. Accurate cellular as well as biochemical markers are essential for this cancer group to identify high risk patients needing adjuvant chemotherapy. In the present study, flow cytometric DNA analysis (DNA-ploidy status, DNA-index, S-phase fraction, S+(G2+M)-phase fraction) and clinico-pathological variables (clinical stage, tumor size, receptor status, age, histological type and grade) as prognostic factors were determined on paraffin-embedded tumors to predict overall survival (OS) and disease-free survival (DFS). Median observation time was 6.1 years (n = 57). S+(G2+M)-phase fraction was the only flow cytometric DNA predictor of overall survival in the univariate analysis (log-rank test): As compared to the patients with lower S+(G2+M)-phase fraction (< or = 9.3%), patients with S+(G2+M)-phase fraction greater than 9.3% had shorter survival (P = 0.039). Of all the clinico-pathological parameters analyzed (univariate analysis), the survival time was found to be longer when estrogen- and/or progesterone-receptor status was positive (overall survival: P = 0.039; disease-free survival: P = 0.017) and the histological grade was low (overall survival: I + II vs III: P = 0.024; I vs II vs III: P = 0.046). In the multivariate analysis, receptor status was the strongest predictor for overall and disease-free survival. These results suggest that S+(G2+M)-phase fraction in premenopausal node-negative breast cancer could be an additional valuable prognostic factor to classify high risk breast cancer patients needing adjuvant chemotherapy.

Eosinophilic myositis resulting from sarcocystosis.

Muscle sarcocystosis is a parasitic infection acquired by ingestion of sporocysts of Sarcocystis species. A case is described where symptoms of fever, chronic myositis and eosinophilia were present. Diagnosis was made via muscle biopsy. Improvement and cure coincided with treatment with cotrimoxazole. A limited review of human muscle sarcocystosis and an outline of the gaps in the knowledge of this infection is presented.

Gut inflammation in children with late onset pauciarticular juvenile chronic arthritis and evolution to adult spondyloarthropathy--a prospective study.

Ileocolonoscopy with biopsy of the colon and terminal ileum was performed prospectively on 12 patients under age 16 with late onset juvenile chronic arthritis (JCA). Inflammatory gut lesions were seen in 9 of these 12 patients; 4 were of the acute type, 5 of the chronic type. Chronic gut inflammation was related to axial inflammatory complaints, inflammatory serum variables, thrombocytosis and sacroiliac radiological abnormalities. A 2nd ileocolonoscopy was performed on 5 of the 12 patients, and a 3rd ileocolonoscopy on 2 of these with persistent synovitis. Gut inflammation and joint inflammation were related; moreover, all 5 patients had chronic inflammatory lesions by the time of the last investigation, one presented with Crohn's disease. The 12 patients were reviewed 3 to 9 years after the first ileocolonoscopy. Four patients were in remission, including the 3 patients with initial normal gut histology. Five patients had developed ankylosing spondylitis (AS), a 6th patient possible AS. Axial inflammatory complaints, a family history of spondyloarthropathies, HLA-B27 positivity, early sacroiliac and peripheral joints radiographic changes, persistence of inflammatory serum variables, thrombocytosis and chronic inflammatory lesions on gut biopsy, are predictive factors in juveniles for evolution to AS. Late onset pauciarticular JCA represents a form of spondyloarthropathy similar to adolescent forms. Persistent gut inflammation could play a role in the pathogenesis of the disease and persistent synovitis.

Juvenile spondyloarthropathies in 1992.

There is some evidence that patients with late onset pauciarticular juvenile chronic arthritis (JCA) should be included among those with spondyloarthropathies, at least during the course of their disease, even if at the onset of the disease we prefer to label them as patients with JCA. The clinical symptoms which could allow us to classify them as spondyloarthritic are frequently absent at the onset of the disease. The gut seems to play a role in the pathogenesis of this form of JCA, though the exact mechanisms must be elucidated further.

Sulfasalazine treatment in juvenile chronic arthritis: an open study.

In an open study, the effect of sulfasalazine was evaluated in the treatment of juvenile chronic arthritis (JCA). Forty-one patients, i.e., 27 boys and 14 girls with JCA under 16 years of age, were included in the study. In all of them, treatment with nonsteroidal antiinflammatory drugs (NSAID) had been unable to control the disease. The patients were divided in 4 subgroups depending on the mode of onset and evolution (Type I = systemic onset, Type II = polyarticular form. Type IIIa and Type IIIb = pauciarticular form). Remission was achieved in 21 patients, significant improvement in 12. Status was unchanged in 4 patients and worsened in 3. In 5 patients side effects were observed, which forced interruption of treatment in 4. Sulfasalazine was stopped in 7 patients: for toxicity in 4 and for inefficacy in 3. In 7 other patients the treatment was terminated after a prolonged remission. These promising results must be confirmed in a double blind versus placebo study, preferably restricted to type III JCA.

Gold-induced aplastic anemia.

Three patients receiving gold salt treatment for rheumatoid arthritis developed severe aplastic anemia. All three patients experienced remission of their disease at the time of the occurrence of marrow aplasia. Reviewing data on these patients and recent literature indicate that fatal marrow aplasia seems to occur more frequently in sero-negative women who respond well to therapy with gold salts. Frequent blood monitoring in search for any pronounced or sustained drop in red, white or platelet count, even within normal range could serve as a warning sign for myelotoxicity. Despite intensive supportive measures and specific therapeutic attempts, all three patients eventually died of septic shock.

Repeat ileocolonoscopy in reactive arthritis.

Ileocolonoscopy on patients with HLA-B27 related disease, reactive arthritis and ankylosing spondylitis (AS) with peripheral arthritis, revealed the presence of inflammatory lesions in biopsy specimens from the ileum in 71 and 60% of the cases, respectively. A 2nd ileocolonoscopy was performed on 14 patients, 4 to 22 months after the first. In 6 of the 7 patients in articular clinical remission, the inflammatory gut lesions had disappeared. The gut biopsies of the 7 patients with active joint disease continued to show inflammatory lesions. One of these patients underwent a 3rd ileocolonoscopy after having gone into clinical remission, possibly secondary to treatment with sulfasalazine; the histology was completely normal. The strong relationship between clinical articular inflammation and gut inflammation seems to support the hypothesis that in B27 related diseases, repetitive exogenous triggering causing transgression of oral tolerance by increased gut permeability, provokes and maintains the joint inflammation.

Late onset pauciarticular juvenile chronic arthritis: relation to gut inflammation.

Ileocolonoscopy with biopsy of the ileum, ileocecal valve and cecum was performed on 32 patients (22 males, 10 females) with juvenile chronic arthritis (JCA) with pauciarticular onset. Mean age at onset of disease was 12 years. Ankylosing spondylitis (AS) was diagnosed in 13 patients; the other 19 cases were classified as reactive arthritis with recurrent or persistent pauciarticular synovitis. Twenty-two patients (68%) were HLA-B27 positive; 8 patients (25%) carried the HLA-Bw62 antigen. Ileocolonoscopy was performed 6 months to 32 years after the initial manifestation of the disease (mean : 9 years). Fourteen patients had macroscopic lesions of the ileum and ileocecal valve although only 8 of these had a history of intestinal complaints. Twenty-six patients (81%) presented histological signs of gut inflammation. Most of the gut abnormalities were classified as active chronic or Crohn-like lesions (19/26). Only 7 patients had acute or bacterial enteritis-like lesions. Acute lesions were seen in only one patient with AS. All but 2 patients with sacroiliitis, in whom signs of gut inflammation were found, had active chronic lesions. All the 8 HLA-Bw62 positive patients had histological evidence of gut inflammation. Only chronic or Crohn-like lesions were found. In the majority of patients with JCA with pauciarticular onset, gut inflammation was found on ileum biopsy. Some of their lesions are related to Crohn's disease, and the presence of the HLA-Bw62 antigen could predispose to the arthritis seen in these cases.

HLA antigens in seronegative spondylarthropathies. Reactive arthritis and arthritis in ankylosing spondylitis: relation to gut inflammation.

The prevalence of HLA-A, B, C and DR antigens was determined and compared in 94 patients with reactive arthritis, 54 patients with ankylosing spondylitis (AS), 37 patients with inflammatory bowel disease (IBD) and in 1,010 apparently normal blood donors. The 185 patients all underwent ileocolonoscopy with biopsy of ileum, ileocecal valve and cecum. HLA-B27 was found elevated in the groups with reactive arthritis (48%, chi 2 = 82, p less than 0.0005) and the AS groups (78%, chi 2 = 157, p less than 0.0005), compared to healthy controls. HLA-Bw62 was significantly raised in the patients with reactive arthritis (34%, chi 2 = 73, p less than 0.0005) (particularly the HLA-B27 negatives (48%, chi 2 = 90, p less than 0.0005) and in the HLA-B27 negative patients with AS (25%, chi 2 = 5.5, p less than 0.02). This did not apply to the other patients with AS (4.7% NS). HLA-Bw62 could be associated with a specific clinical picture of asymmetrical pauciarticular arthritis, accompanied by enthesopathies and sacroiliitis classified as idiopathic reactive arthritis, especially when the disease is of enterogenic origin. The frequency of HLA-Bw62 was very high in patients with reactive arthritis and in patients with AS with active chronic (n = 39, 23%, chi 2 = 13, p less than 0.0005) and Crohn-like lesions (n = 14, 50%, chi 2 = 35, p less than 0.0005) on gut biopsy, normal in patients with acute lesions (n = 35, 11%, NS).(ABSTRACT TRUNCATED AT 250 WORDS)