Nucleic acid-binding specificity and idiotypic expression of canine anti-DNA antibodies

Serum samples collected from eleven lupus dogs during an active phase of the disease all bound native and denatured DNA, poly(dT), poly(I) and poly(G). Nine bound poly(C); 10 bound poly(U); and 3 bound poly(A). Sera from 22 normal dogs were negative with all of these antigens. The canine sera were also probed for the presence of three idiotypic markers, one related to human lupus anti-DNA antibodies and two related to murine lupus antibodies. One canine lupus serum expressed idiotopes related to murine anti-DNA idiotype (Id) termed H130: (a) the canine serum bound to anti-H130 anti-Id; (b) it inhibited the binding of anti-H130 Id to its homologous Id; and (c) the anti-H130 Id inhibited the binding of the canine serum to DNA. These findings suggest that anti-DNA variable regions exhibit interspecies similarities, probably reflecting the conservation of the encoding gene segments through evolution

Single-blind randomized trial of combination antibiotic therapy in rheumatoid arthritis.

OBJECTIVE: To determine the potential clinical efficacy of combination antibiotic therapy in treating rheumatoid arthritis (RA). METHODS: Twenty-one patients with active RA despite second-line treatment were randomized to receive either combination antibiotic therapy (treatment group, n = 11) or no additional therapy (control group, n = 10). Antibiotic therapy was given for 12 months and comprised oral tetracycline 250 mg twice daily, 3 times per week, and intravenous clindamycin infused on 5 consecutive days (300, 300, 600, 600, and 900 mg) followed by weekly infusions of 900 mg for 3 weeks and then fortnightly infusions for the remainder of the 12 months. The primary outcome measure was the American College of Rheumatology 20% (ACR20) response at the end of the initial treatment period of 12 months. RESULTS: Five patients in the treatment group (45%) achieved an ACR20 response at 1 year compared to none in the control group (p = 0.04). Eight patients in the treatment group and 1 in the control group had a greater than 20% improvement in tender joint count (p = 0.008). There were also significant differences between the groups in physician and patient global assessments. Nine patients in the treatment group completed the 6 months' followup; of these, 3 sustained the ACR20 response. CONCLUSION: Combined antibiotic therapy with intravenous clindamycin and oral tetracycline may be useful in the management of active RA. A double-blind, placebo-controlled trial of therapy is justified