Osteoprotegerin in juvenile rheumatoid arthritis: cross talk between the immune and the skeletal systems

Background: Previous studies have linked the decreased local production of osteoprotegerin (OPG), an osteoclastogenesis blocking agent, in the inflamed joints of rheumatoid arthritis patients to the development of bone erosion. Objective: We sought to assess OPG expression in juvenile rheumatoid arthritis (JRA) and to determine its relation to clinical and laboratory markers of disease activity, and radiologic evidence of bone resorption, as well as its relation to the type of onset, duration of illness and different therapeutic modalities. Methods: The study included 40 children and adolescents with JRA, as well as, 20 clinically healthy age- and sex- matched subjects for comparison. The patients underwent clinical evaluation for disease activity by the summed joint index and investigations including assessment of ESR, CRP, antinuclear antibodies and rheumatoid factor. were Serum levels of osteoprotegerin were assayed by ELISA in the patient and control groups. Joints were evaluated radiologically using the modified Larsen index (LI). Results: The serum levels of OPG in the patients [ median (interquartile range): 0.474 (0.4) ng/ml] were comparable to those of the control group [0.495 (0.41) ng/ml] (p=0.29). However, patients with pauciarticular onset JRA had significantly lower OPG levels [0.3 (0.23) ng/ml] than the control group (p= 0.007). The OPG levels were below the 5th percentile of the control value in 60% of pauciarticular and 16.7% of polyarticular JRA cases. Patients with polyarticular JRA had significantly higher values of ESR, activity score and Larsen indices as well as serum OPG levels (p= 0.001, 0.001, 0.002 and 0.02, respectively). OPG levels did not correlate to the ESR or the activity score index values. On the other hand, the duration of illness showed a tendency to be negatively correlated to serum OPG (r= -0.309, p=0.05). LI correlated positively to the activity score index and to the ESR in the JRA patients, whether compiled in one group or classified into subgroups according to disease onset. However, OPG was not significantly correlated to the LI (r= 0.023). The different modalities of therapy did not seem to influence the serum levels of OPG (χ2 = 4.21). Conclusion: Serum OPG expression was low in JRA, especially in the pauciarticular variety. OPG levels were higher in polyarticular JRA, but this does not necessarily have a protective effect since the proinflammatory process is known to promote also the expression of RANKL, an osteoclastogenesis enhancer. While clinical and biochemical parameters of activity, and LI did not correlate to OPG, the latter seemed to be adversely affected by increased disease duration.Keywords: Osteoprotegerin, JRA, osteoclastogenesis, RANKL, bone resorptionEgypt J Pediatr Allergy Immunol 2004; 2(1): 38-4

Immunological and parasitological parameters after treatment with dexamethasone in murine Schistosoma mansoni

This work aimed to evaluate the effect of diphenyl dimethyl bicarboxylate (DDB) and dexamethasone alone and in combination with praziquantel on various parasitological, immunological and pathological parameters reflecting disease severity and morbidity in murine schistosomiasis. DDB and dexamethasone had no effect on worm burden but altered tissue egg distribution. This indicates that, under the schedule used, neither drug interfered with the development of adult worms or oviposition, but both can modulate liver pathology. Dexamethasone resulted in a greater reduction in granuloma size than did DDB. Dexamethasone-treated mice also showed lower levels of serum gamma interferon (IFN-γ), interleukin-12 (IL-12) and IL-4, together with higher IL-10 levels, than infected untreated control animals. These data suggest that dexamethasone is a convenient and promising coadjuvant agent that results in decreased morbidity in murine schistosomiasis