Clinical significance of plasma PAF acetylhydrolase activity
measurements as a biomarker of anaphylaxis: cross-sectional study
Background: Platelet-activating factor (PAF) has a direct role
as a mediator in the pathogenesis of various disorders with an
inflammatory component, including those with allergic aetiology. The
peripheral blood concentration of PAF is dynamically regulated by plasma
PAF acetylhydrolase (PAF-AH). Previous studies suggest that low activity
of plasma PAF-AH could be a predictive marker for increased severity of
some types of allergic hypersensitivity reactions – especially
anaphylaxis. Aim of the study: The purpose of the study was to
evaluate the association between plasma PAF-AH activity and severity in
patients with anaphylactic reactions following a wasp or bee sting.
Methods: The study group of 89 patients was divided into two
subgroups depending on the increasing severity of the most severe
anaphylactic reaction in the past, which was assessed according to the
Müller’s scale. A control group of 20 people was established. Plasma
PAF-AH activity was measured using a colorimetric method.
Results: It has been observed that plasma activity of
platelet-activating factor acetylhydrolase was significantly lower in
patients with anaphylaxis history compared to the control group with
negative atopic history (on average 21.38 nmol/min/ml for the control
group, 9.47 nmol/min/ml for the first subgroup and 10.16 nmol/min/ml for
the second subgroup, in both cases p < 0.0001).
Conclusion: The plasma activity of PAF-AH is a promising
parameter that can help to distinguish a group of patients not
threatened with development of anaphylaxis and not requiring laborious
or expensive prophylactic procedures.