Serum interleukin 12 concentration in juvenile chronic arthritis.

OBJECTIVES: The aim of this study was to evaluate serum interleukin (IL) 12 concentration in patients with juvenile chronic arthritis (JCA), according to disease subtype, activity, and duration. IL12 has been demonstrated to prime the selective expansion of T helper (Th) cells with a Th1-type pattern of cytokine production. METHODS: Sixty eight serum samples from 50 JCA patients (12 systemic, 12 polyarticular, 26 pauciarticular), 20 serum samples from age matched healthy controls were tested with two different immunoassays specific for total IL12 (p40 and p70 heterodimer) and for IL12 (p70) heterodimer, respectively. The following disease activity parameters were evaluated: (a) presence of arthritis at least in one joint, (b) physician global estimate of disease activity, (c) disability index according to the Childhood Health Assessment Questionnaire (CHAQ), (d) C reactive protein (CRP). RESULTS: Total IL12 (p40 and p70 heterodimer) was significantly higher in JCA active patients than in those on clinical remission and in healthy controls (p < 0.001). Conversely, detectable concentrations of IL12 (p70) heterodimer were found in three active JCA patients only. Moreover, total IL12 (p40 and p70 heterodimer) showed a significant negative correlation both with time from disease diagnosis (r = -0.29, p = 0.04) and, for the pauciarticular subgroup, with disease activity duration (r = -0.71, p < 0.001). CONCLUSIONS: This study shows that the p40 moiety of IL12 is increased in serum samples from active JCA patients, especially in the earliest phases of the disease, whereas biological active IL12 (p70) heterodimer is virtually undetectable.

Differences in tumor necrosis factor-alpha soluble receptor serum concentrations between patients with Henoch-Schönlein purpura and pediatric systemic lupus erythematosus: pathogenetic implications.

OBJECTIVE: Animal models of immune complex mediated tissue injury have shown different patterns of proinflammatory cytokine production according to the subtype of immunoglobulin involved. The IgA immune complex model differs from the IgG model by the lack of involvement of tumor necrosis factor (TNF) in the pathogenesis of tissue damage. We investigated in age matched patients the possible difference in TNF involvement in a predominantly IgA mediated disease, Henoch-Schönlein purpura (HSP), in comparison with systemic lupus erythematosus (SLE), in which vascular injury is mostly associated with local deposition of IgG immune complexes. METHODS: Serum concentrations of TNF-alpha and its soluble receptors (sTNF-R) p55 and p75 were studied in 20 patients with pediatric SLE at various degrees of disease activity, in 16 patients with highly active HSP, and in 15 healthy controls by enzyme amplified sensitivity immunoassay. SLE disease activity was evaluated using 2 scores, the European Consensus Group Study for SLE Disease Activity Criteria and the SLE Disease Activity Index. RESULTS: Serum concentrations of TNF-alpha fell within the normal range in patients with both SLE and HSP irrespective of disease activity. Conversely, patients with SLE displayed increased serum levels of sTNF-R that correlated positively with the degree of disease activity (r = 0.60, p < 0.001; r = 0.71, p < 0.001, for p55 and p75, respectively). In contrast, no difference in the serum levels of sTNF-R was found between patients with highly active HSP and controls. CONCLUSION: Our study provides the first circumstantial evidence that pediatric SLE and HSP are characterized by differential involvement of TNF in the pathogenesis of tissue damage.

Serum p55 and p75 tumour necrosis factor receptors as markers of disease activity in juvenile chronic arthritis.

OBJECTIVE: To determine the expression of tumour necrosis factor alpha (TNF alpha) and its soluble receptors (p55 and p75) in the sera and synovial fluid of patients with juvenile chronic arthritis (JCA), and their correlation with disease activity parameters. METHODS: Ninety eight sera from 45 patients with JCA (14 systemic, 12 polyarticular, 19 pauciarticular), 20 sera from age matched healthy controls, and five synovial fluids from five antinuclear antibody (ANA) positive pauciarticular JCA patients were tested for the presence of TNF alpha, soluble TNF receptors p55 and p75 (sTNFRp55, sTNFRp75), and interleukin-6 (IL-6) by an enzyme amplified sensitivity immunoassay. Physician global estimate of disease activity, weekly fever score and joint score, C reactive protein (CRP), erythrocyte sedimentation rate (ESR), and haemoglobin concentration were evaluated as parameters of disease activity. The expression of p55 and p75 on peripheral mononuclear cells (MNCs) from five patients with systemic JCA and synovial MNCs from five ANA positive patients with pauciarticular JCA was evaluated by flow cytometry. RESULTS: TNF alpha serum concentrations did not differ significantly between the patients with active JCA and the control group. No correlation was found between TNF alpha and parameters of disease activity, but both p55 and p75 showed a significant positive correlation with the physician global estimate of disease activity (p < 0.001), ESR (p < 0.001), CRP (p < 0.001), and serum concentrations of IL-6 (p < 0.001). Serum concentrations of haemoglobin correlated inversely with the concentrations of p55 and p75 (p < 0.001). Synovial lymphocytes selectively expressed the p75 surface receptor. CONCLUSIONS: sTNFRp55 and sTNFRp75 each represent a sensitive marker of disease activity in JCA. Their increased expression in biological fluids may support the hypothesis that TNF alpha has a role in the pathogenesis of JCA.

Antiphospholipid antibodies in paediatric systemic lupus erythematosus, juvenile chronic arthritis and overlap syndromes: SLE patients with both lupus anticoagulant and high-titre anticardiolipin antibodies are at risk for clinical manifestations related to the antiphospholipid syndrome.

Antiphospholipid antibodies (APA) are often associated with severe clinical manifestations, especially in the setting of systemic lupus erythematosus (SLE). Here we have investigated the prevalence of anticardiolipin antibodies (aCL) and lupus anticoagulant (LA) in paediatric patients affected with SLE, JCA and overlap syndromes (OS) and correlated the presence of aCL and LA with clinical features. aCL were assayed by enzyme-limited immunoassay; LA was determined by activated partial thromboplastin time and the kaolin clotting time test. aCL and LA assays were performed in parallel on at least two occasions over a 7-30-month follow-up. Fifteen out of nineteen (79%) SLE patients had aCL and 8/19 (42%) had LA. Six SLE patients displayed manifestations that were APA-related: deep venous thromboses, autoimmune haemolytic anaemia, pulmonary hypertension, neurological alterations. Five out of six symptomatic patients had both LA and high-titre aCL. In contrast, JCA and OS patients had usually low-titre aCL, no detectable LA and no APA-related manifestations. aCL persisted at high titre over time in SLE patients, but was only transiently detected in JCA and OS patients. This study shows that the simultaneous positivity for LA and high-titre aCL allows the identification of paediatric SLE patients who are at risk not only for thrombosis, but also for other APA-related clinical features.