[Alpha-2 Macroglobulin Serum Level in Patients with Alpha-1 Antitrypsin Deficiency].

Alpha-2 Macroglobulin (A2M) is a plasma protein with proteolytic effects on many proteases. In patients with an inborn alpha-1 antitrypsin deficiency (AATD) the homeostasis between proteases and antiproteases is disturbed. The aim of this study was to compare the levels of AAT and A2 M in patients and controls. We hypothesized that in patients with AATD A2 M levels are elevated.  Patients with AATD (polymorphism PiZZ, PiSZ, PiMZ and rare gene variants) as well as healthy volunteers (PiMM) were tested for A2 M and AAT levels. The concentration of the proteins was measured by nephelometry. The polymorphisms PiZ and PiS were detected by polymerase chain reaction (PCR), the rare genetic variants were identified by sequencing.  In our study, a total of 291 individuals were included. It could be shown that a significant increase in A2 M levels in the serum could be observed in the presence of a gene polymorphism (PiZZ) and an alpha-1 antitrypsin serum level < 50 mg/dl compared to the healthy volunteers.  In this study, an inverse correlation between the serum levels of AAT and A2 M was found in the presence of a gene polymorphism (PiZZ). Further studies are necessary to elucidate the clinical significance of increased A2 M serum levels in patients with severe AAT deficiency Pi*ZZ and rare gene variants whose AAT serum level is < 50 mg/dl.