ORIGINAL ARTICLES   

International Angiology 2000 March;19(1):64-8

Copyright © 2001 EDIZIONI MINERVA MEDICA

lingua: Inglese

Plasma and tissue levels of collagen types I and III markers in patients with abdominal aortic aneurysms

Treska V., Topolcan O.

From the Department of Surgery and * Internal Medicine II, University Hospital, Plzen, Czech Republic

Back­ground. To study the lev­els of the ami­no­ter­mi­nal pro­pep­tide of type III (­PIIINP) and car­box­y­ter­mi­nal pro­pep­tide of type I pro­col­lag­en (PICP) in plas­ma and in the wall of abdom­i­nal aor­tic aneu­rysms in rela­tion to their size and symp­tom­a­tol­o­gy. ­PIIINP ­serves as a mark­er of turn­over and PICP as a mark­er of the syn­the­sis of the cor­re­spond­ing col­la­gens.
Meth­ods. Experi­men­tal ­design: A pros­pec­tive non-ran­dom­ised study. Set­ting: Uni­ver­sity Hos­pi­tal, Plzen, Czech Repub­lic. ­Patients: ­Eighty-six ­patients who under­went resec­tion of abdom­i­nal aor­tic aneu­rysms, aver­age age 70.1 years (range 45 to 91 years), men to women ratio 5:1. The indi­ca­tion for resec­tion was its symp­tom­a­tol­o­gy with­out rela­tion to its diam­e­ter, and diam­e­ter over 5 cm in asymp­to­mat­ic ­patients. Twen­ty ­patients (with sim­i­lar age and gen­der dis­tri­bu­tion) sched­uled for her­nia ­repair or lapar­os­cop­ic chol­e­cys­tec­to­my were exam­ined as a con­trol group. Main out­come meas­ures: The plas­ma and tis­sue PICP and ­PIIINP con­cen­tra­tions were eval­u­at­ed using radio­im­mu­noas­say meth­ods. The plas­ma sam­ples were taken from the cubi­tal vein with­out the use of a tour­ni­quet. Full-thick­ness sec­tions of the ante­ri­or abdom­i­nal aor­tic aneu­rysm wall at the site of the larg­est aneu­rysm diam­e­ter were taken at the time of oper­a­tion.
­Results. A sig­nif­i­cant dif­fer­ence ­between plas­ma ­PIIINP lev­els in ­patients with abdom­i­nal aor­tic aneu­rysms and the con­trol group was ­observed (p<0.01). No cor­re­la­tion of PICP, ­PIIINP plas­ma lev­els with diam­e­ter and symp­tom­a­tol­o­gy of abdom­i­nal aor­tic aneu­rysms was found. The ­increase in ­PIIINP tis­sue con­cen­tra­tion was sig­nif­i­cant in ­patients with increas­ing diam­e­ter and pos­i­tive symp­tom­a­tol­o­gy (p<0.01). No sta­tis­ti­cal­ly sig­nif­i­cant cor­re­la­tion ­between plas­ma and tiss­ue PICP and ­PIIINP con­cen­tra­tions was ­observed.
Con­clu­sions. The metab­olism of type III col­la­gen is ­increased in ­patients with abdom­i­nal aor­tic aneu­rysm, in con­trast to type I col­la­gen. The ­result is a deg­ra­da­tion of col­la­gen in the aneu­rys­mal wall. The turn­over of type III col­la­gen increas­es with the enlarge­ment of the aneu­rysm diam­e­ter and with the pos­i­tive symp­tom­a­tol­o­gy. Deg­ra­da­tion of type III col­la­gen in the aneu­rys­mal wall has there­fore a fun­da­men­tal sig­nif­i­cance for abdom­i­nal aor­tic aneu­rysm rup­ture. ­Because no cor­re­la­tion ­between plas­ma and tis­sue lev­els of ­PIIINP was found, the plas­ma lev­els of ­PIIINP can­not be used as the plas­ma mark­ers of this pro­cess.