Allergy to dental prosthesis

Anti-DNA antibody modified coronary stent for plasmid gene delivery: results obtained from a porcine coronary stent model

BACKGROUND

Previous work in our laboratory has demonstrated that the anti-DNA antibody-immobilized stent results in highly site-specific gene delivery in a rabbit carotid model. As a result of the similarity in the anatomy and physiology of the pig and human cardiovascular systems, the porcine coronary stent model was used in the present study to evaluate the site-specificity, efficiency and long-term therapeutic effect of this gene delivery system in pig coronary arteries.

METHODS

A reporter plasmid pEGFP (pEGFP-C1) was tethered on the antibody-immobilized stents and assessed for site-specificity and efficiency in a pig coronary stent model. Inducible nitric oxide synthase (NOS) cDNA (pcDNA3.1-iNOS) was tethered on the stent as a therapeutic gene to evaluate the site-specificity and long-term therapeutic effect of this novel gene delivery system for the inhibition of restenosis after coronary stenting for 28 days.

RESULTS

Both the pEGFP-C1 and pcDNA3.1-iNOS tethered stents achieved site-specific gene transfection without distal spreading in the porcine coronary model. The overall GFP transfection efficiency was 2.6 ± 0.9% of the total cells, whereas the neointimal transfection was more than 6%. Histology and morphology studies showed no significant artery stenosis and intimal proliferation for 28 days after coronary stenting using pcDNA3.1-iNOS tethered stents.

CONCLUSIONS

For the first time, we report the successful use of anti-DNA antibody-immobilized stent as plasmid gene delivery system that possess high efficiency and site-specificity in a porcine coronary stent model. The novel system showed long-term therapeutic effects on the inhibition of restenosis when pcDNA3.1-iNOS was tethered on the stent.

Nickel and molybdenum contact allergies in patients with coronary in-stent restenosis

BACKGROUND

Coronary in-stent restenosis might be triggered by contact allergy to nickel, chromate, or molybdenum ions released from stainless-steel stents. We investigated the association between allergic reactions to stent components and the occurrence of in-stent restenosis.

METHODS

Patients with coronary stainless-steel stents who underwent angiography for suspected restenosis were consecutively included in this study. Quantitative coronary angiography for analysis of percentage diameter stenosis was done on 131 patients (mean age 62 years [SD 9]) with 171 stents 6.1 months (2.7) after stent implantation. All patients underwent epicutaneous patch tests (Finn chamber method) for nickel, chromate, molybdenum, manganese, and small 316L stainless-steel plates. Patch tests were assessed by independent dermatologists after 48 h, 72 h, and when necessary 96 h of contact with the potential allergen.

FINDINGS

In-stent restenosis (> or =550% diameter stenosis) occurred in 89 patients. All ten patients with positive patch-test results had restenoses (p=0.03). Four male patients had positive reactions to molybdenum, and seven patients (four male, three female) had reactions to nickel. No patient with an allergic reaction to the standard test substances had a positive reaction to the stainless-steel plates. All patients with positive results had recurrent angina pectoris and needed target-vessel revascularisation.

INTERPRETATION

Patients with allergic patch-test reactions to nickel and molybdenum had a higher frequency of in-stent restenoses than patients without hypersensitivity. Allergic reactions to nickel and molybdenum released from stents may be one of the triggering mechanisms for in-stent restenosis.