Distribution and clinical significance of blood dendritic cells in children with juvenile idiopathic arthritis.

BACKGROUND: A role for dendritic cells (DC) in the development of adult rheumatoid arthritis has been suggested. To date, this problem has been poorly explored in juvenile idiopathic arthritis (JIA). OBJECTIVE: To analyse distribution and maturation status of blood DC (BDC) in JIA. METHODS: Absolute BDC counts were assessed by the "single platform" method in peripheral blood (PB) of 47 untreated children with JIA and 32 healthy controls. Moreover, BDC were investigated in JIA synovial fluid (SF). When the panel of monoclonal antibodies against BDC antigens (BDCA) was used, three BDC subpopulations were determined: myeloid type 1 (mDC1; BDCA-1+/HLA-DR+/CD19-), myeloid type 2 (mDC2; BDCA-3+/HLA-DR+/CD14-) and plasmacytoid (pDC; BDCA-2+/HLA-DR+/CD123+). RESULTS: A considerable deficiency of all subtypes of BDC was found in the PB of children with JIA. BDC counts in JIA SF were significantly higher than in PB both from children with JIA (p<0.001) and healthy children (p<0.001). SF BDC, especially mDC1 and mDC2 subtypes, had significantly higher expression of maturation markers (CD40, CD80, CD86 or CD83 antigens) than those from PB. A smaller number of PB BDC at diagnosis correlated significantly with poor response to treatment. CONCLUSIONS: A deficiency of BDC in PB is accompanied by enrichment of SF with those cells. Probably, circulating BDC migrate to joints where they undergo maturation and help to mediate and maintain the local immune response. Interestingly, the level of PD BDC deficiency seems to influence the outcome in children with JIA.

Regulation of peripheral blood and synovial fluid lymphocyte apoptosis in juvenile idiopathic arthritis.

OBJECTIVE: Complex regulatory mechanisms are involved in the induction of apoptosis. Their impairment may play a role in the pathogenesis of several autoimmune diseases. Recently, we have described higher incidences of spontaneous apoptosis of peripheral blood (PB) lymphocytes in children with juvenile idiopathic arthritis (JIA). This study aimed to evaluate the regulatory mechanisms that may be responsible for this phenomenon. METHODS: Thirty-four JIA children were examined and compared with 20 healthy children of similar ages. Expression of regulatory proteins p53, Bax and Bcl-2 in lymphocytes isolated from PB and synovial fluid (SF) was assessed. Serum and SF levels of interleukin-15 (IL-15) were also evaluated. RESULTS: The study showed significantly decreased Bcl-2 expression in JIA PB lymphocytes, compared to both healthy control (p = 0.03) and JIA SF lymphocytes (p = 0.005). There were no significant differences found in Bax expression between groups or compartments examined. However, the Bax/Bcl-2 ratio was nearly two-fold higher in PB lymphocytes than in SF of JIA patients (p = 0.001). p53 expression in PB lymphocytes from both JIA and control children did not statistically differ. In JIA, however, p53 was significantly higher in PB than SF lymphocytes (p = 0.016). IL-15 levels were about 20-fold higher in JIA SF than in serum from either JIA or healthy children (p < 0.0001). CONCLUSION: The results suggest that a higher incidence of apoptosis of PB lymphocytes observed in JIA may be associated with down-regulation of Bcl-2, rather than with changes in expression of Bax and p53. In contrast, the low p53 expression and elevated IL-15 appear to provide mechanisms responsible for suppression of apoptosis in SF cells from JIA patients.

Apoptosis of peripheral blood lymphocytes in patients with juvenile idiopathic arthritis.

BACKGROUND: Recent data suggested that abnormalities in mechanisms regulating apoptosis may have a role in the development of the rheumatoid process. OBJECTIVE: To evaluate different aspects of apoptosis in children with juvenile idiopathic arthritis (JIA). METHODS: The frequency of TUNEL positive peripheral blood (PB) lymphocytes (apoptotic index (AI)), as well as serum CD95 (APO1/Fas) antigen expression and serum levels of sFas and interleukin 15 (IL15), were examined in 44 cases of JIA. Results were correlated with type of onset, activity of JIA, and acute phase indicators. RESULTS: The AI of lymphocytes was significantly higher in patients with JIA than in controls (p=0.020). The mean AI of lymphocytes was increased in JIA with systemic type of onset and high activity (p=0.001). Moreover, IL15 levels in systemic disease were higher than in controls (p=0.012). An increased AI correlated with raised IL15 (p=0.046), erythrocyte sedimentation rate (p=0.005) and C reactive protein (CRP; p=0.017). Additionally, correlation was found between IL15 and CRP levels (p=0.039). CD95 and sFas levels were unchanged compared with controls. CONCLUSION: PB lymphocytes of children with JIA have an increased tendency to undergo apoptosis. The degree of apoptosis depends on the type of onset and activity of JIA and correlates with serum levels of IL15. Further studies are needed to explain whether this is an epiphenomenon of the disease activity or is related to the pathogenesis of JIA.

HPTLC screening assay for urinary cotinine as biomarker of environmental tobacco smoke exposure among male adolescents.

For selective screening determination of urinary cotinine, i.e. (S)-1-methyl-5-(3-pyridyl)-2-pyrrolidinone, the major metabolite of nicotine, the high-performance thin-layer chromatographic (HPTLC) method have been proposed. Prior the final HPTLC analysis the procedure required a solid-phase extraction (SPE) of cotinine from collected urine samples with 1-methyl-2-pyrrolidinone as an internal standard. Densitometrical quantitation of cotinine on the chromatograms have been performed with a 16-grayscale scanner using the specialized software implemented on a desktop microcomputer. The lower detection limit of cotinine was 6 microg/l allowing the method to be applied for the measurement a concentration of this compound in urine samples collected from 35 elementary schoolboys exposed on both moderate and/or significant ETS. The mean recovery of cotinine from urine samples was 93%. The mean intra-day accuracy for the analysis of cotinine in range 6-750 microg/l. including four paralell measurements, was 2.9 %. The results of cotinine measurements by proposed SPE-HPTLC procedure were used in the pilot studies for assessment of hazard from home ETS on the health status of elementary schoolboys, especially an increased risk for infectious respiratory track diseases.

Vitamin E, thiobarbituric acid reactive substance concentrations and superoxide dismutase activity in the blood of children with juvenile rheumatoid arthritis.

OBJECTIVE: To study the role of active oxygen species in tissue injury in rheumatoid arthritis. METHODS: We examined the levels of thiobarbituric acid reactive substances (TBARS) and antioxidants of the first line antioxidative defence of the organism, i.e. vitamin E (VE) and superoxide dismutase (SOD) in the blood of 74 young patients with juvenile rheumatoid arthritis (JRA) and in 138 healthy children, all aged 3-15. RESULTS: A statistically significant increase of TBARS was found in the blood plasma of the children with JRA compared with the control group. In the whole group of patients and in the patients over 6 years of age, the VE concentration was in the red blood cells (RBC) was significantly lower in children who had suffered from JRA for more than one year and in those with the systemic form of the disease. The type of treatment also affected the values for the plasma VE and SOD in the RBC. CONCLUSION: Our results seem to confirm the supposition of increased oxidative stress in children with JRA and low antioxidant levels in terms of SOD activity and vitamin E concentrations.

Chemiluminescence of peripheral blood leukocytes and activity of an inflammatory process in juvenile chronic arthritis (JCA).

The oxidative metabolites have been implicated in the aetiology and pathology of rheumatoid arthritis. In our work we endeavoured to deal with polymorphonuclear leukocytes (PMNLs) ability to generate oxygen free radicals (OFRs). PMNLs metabolic activity was assessed by the means of chemiluminescence (CL) method. We observed significantly higher PMNLs metabolic activity in children suffering from JCA in comparison to the healthy group. Greater activity of the rheumatoid process was accompanied by an increased PMNLs activity. The results constitute another piece of evidence confirming the role of PMNLs in the pathogenesis of JCA.

Concentrations of cloxacillin and erythromycin in the tonsils of children after administration of therapeutic doses.

The treatment of infections in the ring of Waldeyer in children is an ever present problem. Most infections are caused by group A streptococci, and various antibiotics are routinely used for their treatment. In many cases, however, this treatment is ineffective as demonstrated by prolonged disease duration and recurrences. This may be due to the resistance of the pathogens to the used antibiotic, too low dose, or inadequate penetration of the drug into the focus of infection. To explain this problem the reported investigation was undertaken carrying out bacteriological investigations of the removed tonsils and determining antibiotic concentrations in tonsil homogenates and in the serum after cloxacillin and erythromycin treatment of 45 children aged 4-14 years subjected to tonsillectomy or adenotomy . It was found that the most frequent aetiological factors in angina and adenoiditis were group A streptococci. Cloxacillin and erythromycin are the antibiotics penetrating well into the lymphoid tissue and reaching high concentrations in the focus of infection but the courses of treatment should not be shorter than 10 days.