ORIGINAL ARTICLES   

Panminerva Medica 2000 March;42(1):17-21

Copyright © 2009 EDIZIONI MINERVA MEDICA

lingua: Inglese

Low serum alpha-1-antitrypsin specific activity in monoclonal gammopathies

Jelic-Ivanovic Z., Stankovic B., Topic A., Spasojevic-Kalimanovska V., Spasic S.

From the Department of Medical Biochemistry University School of Pharmacy Belgrade, Serbia Republic of Yugoslavia

Background. Serum α1-anti­trypsin (α1AT) ­antigen con­cen­tra­tion is ele­vated in malig­nan­cies as the ­result of ­acute ­phase reac­tion. In the ­present ­study, we exam­ined ­whether the α1AT ele­va­tion in mono­clonal gam­mop­a­thies was accom­pa­nied by an ade­quate ­increase of its func­tional ­activity.
Methods. In ­this ­case-con­trol ­study, ­serum α1AT con­cen­tra­tion was meas­ured in 187 ambu­la­tory ­patients ­with mono­clonal gam­mop­a­thies and 320 ­healthy ­blood ­donors ­matched ­according to sex and age. The α1AT ­antigen con­cen­tra­tion was ­assayed by immu­non­e­phe­lom­etry, ­whereas its func­tional ­activity was meas­ured as ­trypsin inhib­i­tory ­capacity (TIC). The spe­cific α1AT inhib­i­tory ­activity (SIA) was cal­cu­lated, ­defined as the TIC/­antigen con­cen­tra­tion ­ratio.
Results. The α1AT ­antigen con­cen­tra­tions ­obtained in the ­patients’ sam­ples ­were ­very sig­nif­i­cantly ­higher as com­pared ­with the cor­re­sponding ­values in the con­trol ­group (­mean±SD =134±41.9% of ­normal, p<0.001). However, the TIC ­values ­were ­higher in the ­patients ­than in the ­healthy con­trols ­only by 4% (104±23.8%, p<0.05). The spe­cific α1AT ­activity was ­very sig­nif­i­cantly ­lower in the ­patients, as com­pared ­with the con­trols (p<0.001), indi­cating ­that ­serum α1AT in mono­clonal gam­mop­a­thies was par­tially inac­tive.
Conclusions. As ­poor cor­re­la­tion ­between the TIC ­values and the ­antigen con­cen­tra­tions was ­obtained in the ­patient ­group as ­well as the ­decreased spe­cific α1AT activ­ities, the TIC ­values in ­patients ­with mono­clonal gam­mop­a­thies ­should be inter­preted ­with cau­tion.