ABSTRACT
Several o f th e majo r plasma protein s liste d i n Tabl e 7.5 hav e bee n discusse d i n
this chapter , an d other s (e.g. , prealbumi n and ceruloplasmin ) were discusse d i n
Chapter 6 . Immunoglobulin s wi l l b e deal t wi t h i n Chapte r 14 . I t shoul d b e
mentioned tha t plasm a contain s a numbe r o f hormone-bindin g proteins , exam -
ples bein g th e thyroxine-bindin g globuli n (TBG ) and th e steroid-bindin g pro -
teins transcorti n an d a-1 aci d glycoprotei n (orosomucoid) . A ver y importan t
glycoprotein fro m a diagnosti c poin t o f v ie w i s a 2 -antitrypsin, whos e jo b i s t o
protect lun g tissu e agains t proteolyti c damage . I t is especiall y activ e agains t th e
enzyme elastase release d b y neutrophils . Smokin g increase s neutrophi l level s i n
the lun g an d henc e th e releas e o f elastase . A t the sam e time , smokin g decrease s
^-ant i tryps in level s i n th e bloodstream . Smoker s are thus especiall y susceptibl e
to lun g damag e b y elastase , th e resul t being th e developmen t o f emphysema . a t-
Antitrypsin level s o f emphysem a patient s ar e almos t alway s belo w norma l a n d
can serv e a s a diagnosti c too l fo r thi s disease . Lipoprotein s ar e a n importan t
group o f plasm a proteins tha t wi l l b e discusse d i n Chapte r 19 .
