Kits
α1-Antitrypsin (IDK® α1-Antitrypsin), ELISA
Kits
Description
Intestinal protein loss is a serious consequence of various systemic or local gastrointestinal
diseases (e.g. allergies, chronic inflammation, malignancies). These pathologies
damage the mucosal integrity and/or cause lymphostasis, thereby leading to
an increased transfer of plasma proteins into the bowel lumen. Subsequently, hypoproteinemia
accompanied with edema may develop. This condition is diagnosed by
exclusion of other sources of protein loss and by proof of an elevated α1
-antitrypsin
concentration in stool.
In serum, α1
-antitrypsin represents the majority of serine protease inhibitors and protects
tissues from protease damages during inflammation. The protein is synthesized
primarily in the liver but also to a small extent in intestinal macrophages, monocytes,
and intestinal epithelial cells. Since α1
-antitrypsin is relatively resistent against enzymatic
digestion, the secreted amount in stool reflects the internal concentration of
the protein. An elevated α1
-antitrypsin stool concentration is therefore a widely recognized
marker for intestinal protein loss and for an increased mucosal permeability.
In clinical routine, the α1
-antitrypsin clearence (ratio of the α1
-antitrypsin ELISA values
of stool and serum samples) has been established along with the sole determination
of the 24h α1
-antitrypsin secretion in stool. Thus the group of J. S. Fordtran
reports that the sole determination of of the α1
-antitrypsin concentration in stool
yielded false positive or false negative results in 21% of the patients compared to the
α1
-antitrypsin clearence measurement (Strygler et al. 1990).
The analytical quality of the IDK® α1
-antitrypsin ELISA surpasses by far the conventional
radial immunodiffusion (RID) technique in the determination of serum, stool
and tissue culture supernatants. In direct comparison, the concentrations measured
with the ELISA were approximately 30% above the corresponding RID levels.
Cell culture supernatants of an intestinal cell line as well as fecal samples of
lymphostasis patients yielded negative results with RID. Our ELISA could detect α1
-
antitrypsin in all of these samples, in some of them even in very high concentrations.
These results clearly prove that the α1
-antitrypsin ELISA is far more sensitive than
the conventional method and that it recognizes not only hepatic but also enteral
α1
-antitrypsin. The discrepancy of both methods and hence the superiority of the
ELISA to RID is especially striking in the analysis of extremely high enteral protein
losses. The combination of two specific antibodies in our IDK® α1
-antitrypsin ELISA
widely excludes the possibility of false negative results thereby enabling a reliable
diagnostics of enteral protein loss.
diseases (e.g. allergies, chronic inflammation, malignancies). These pathologies
damage the mucosal integrity and/or cause lymphostasis, thereby leading to
an increased transfer of plasma proteins into the bowel lumen. Subsequently, hypoproteinemia
accompanied with edema may develop. This condition is diagnosed by
exclusion of other sources of protein loss and by proof of an elevated α1
-antitrypsin
concentration in stool.
In serum, α1
-antitrypsin represents the majority of serine protease inhibitors and protects
tissues from protease damages during inflammation. The protein is synthesized
primarily in the liver but also to a small extent in intestinal macrophages, monocytes,
and intestinal epithelial cells. Since α1
-antitrypsin is relatively resistent against enzymatic
digestion, the secreted amount in stool reflects the internal concentration of
the protein. An elevated α1
-antitrypsin stool concentration is therefore a widely recognized
marker for intestinal protein loss and for an increased mucosal permeability.
In clinical routine, the α1
-antitrypsin clearence (ratio of the α1
-antitrypsin ELISA values
of stool and serum samples) has been established along with the sole determination
of the 24h α1
-antitrypsin secretion in stool. Thus the group of J. S. Fordtran
reports that the sole determination of of the α1
-antitrypsin concentration in stool
yielded false positive or false negative results in 21% of the patients compared to the
α1
-antitrypsin clearence measurement (Strygler et al. 1990).
The analytical quality of the IDK® α1
-antitrypsin ELISA surpasses by far the conventional
radial immunodiffusion (RID) technique in the determination of serum, stool
and tissue culture supernatants. In direct comparison, the concentrations measured
with the ELISA were approximately 30% above the corresponding RID levels.
Cell culture supernatants of an intestinal cell line as well as fecal samples of
lymphostasis patients yielded negative results with RID. Our ELISA could detect α1
-
antitrypsin in all of these samples, in some of them even in very high concentrations.
These results clearly prove that the α1
-antitrypsin ELISA is far more sensitive than
the conventional method and that it recognizes not only hepatic but also enteral
α1
-antitrypsin. The discrepancy of both methods and hence the superiority of the
ELISA to RID is especially striking in the analysis of extremely high enteral protein
losses. The combination of two specific antibodies in our IDK® α1
-antitrypsin ELISA
widely excludes the possibility of false negative results thereby enabling a reliable
diagnostics of enteral protein loss.