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 research 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. 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.
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. The first subgroup included participants with a history of hypersensitivity reactions up to grade II. The second subgroup consisted of patients who have experienced at least one grade III or IV reactions in the past. A control group of 20 people was established. Plasma PAF-AH activity was measured using a colorimetric method.
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).
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.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Allergic cross-reactivity is an important epidemiological issue in all age groups. It is caused by a non-specific binding of both primary allergen as well as allergens causing secondary ...cross-reactivity by the same IgE antibodies. This phenomenon results from the similarity of the molecular structure of allergen epitopes and leads to a number of allergic cross-reactivity syndromes, such as pollen-food syndromes, pork-cat syndrome or latex-fruit syndrome. They are characterized by rich symptomatology and the possible occurrence of symptoms related to various systems, including life-threatening systemic reactions. In many cases, specific allergen groups responsible for certain cross-reactions, such as plant profilins, fish parvalbumins or invertebrate tropomyosins, have been identified. Also, some of the factors affecting the spatial conformation of allergens, and thus modifying their allergenic potential, have been identified. Despite all these achievements, the diagnostics of cross reactivity syndromes still remains difficult due to the limited available methods and the possible occurrence of overlapping phenomena such as co-sensitisation, asymptomatic cross-sensitisation or IgE-independent or nonimmunological adverse drug reactions. Therefore, careful management based on medical history as well as avoidance of unjustified treatment methods, e.g. diet therapy or immunotherapy, are necessary. This is of great importance as the incidence of food allergies is expected to increase mainly due to the progressive rise in the prevalence of inhalant allergies to pollens.
Platelet activating factor (PAF) has a proven role as a mediator in pathogenesis of various disorders with inflammatory component, including those with allergic aetiology. The peripheral blood ...concentration of PAF is dynamically regulated by plasma PAF acetylhydrolase. An association between the enzyme activity and incidence as well as progression of numerous ailments, such as diabetes, atherosclerosis or coronary artery disease, has been demonstrated. In terms of allergic disorders those connections are underlined in case of bronchial asthma and anaphylaxis. The studies suggest that low activity of plasma PAF acetylhydrolase could be a potential predictive marker for increased severity of some types of allergic hypersensitivity reactions. The possible connections between enzyme activity and population polymorphism, levels of lipoprotein fractions, applied pharmacotherapy and chronic disorders of different aetiology appear to be also interesting within the context of allergic diseases. The aim of the following review is to systematize the current state of knowledge regarding possible importance and utilization of platelet activating factor acetylhydrolase measurement for the needs of allergology.
Allergic cross-reactivity is an important epidemiological issue in all age groups. It is caused by a non-specific binding of both primary allergen as well as allergens causing secondary ...cross-reactivity by the same IgE antibodies. This phenomenon results from the similarity of the molecular structure of allergen epitopes and leads to a number of allergic cross-reactivity syndromes, such as pollen-food syndromes, pork-cat syndrome or latex-fruit syndrome. They are characterized by rich symptomatology and the possible occurrence of symptoms related to various systems, including life-threatening systemic reactions. In many cases, specific allergen groups responsible for certain cross-reactions, such as plant profilins, fish parvalbumins or invertebrate tropomyosins, have been identified. Also, some of the factors affecting the spatial conformation of allergens, and thus modifying their allergenic potential, have been identified. Despite all these achievements, the diagnostics of cross reactivity syndromes still remains difficult due to the limited available methods and the possible occurrence of overlapping phenomena such as co-sensitisation, asymptomatic cross-sensitisation or IgE-independent or nonimmunological adverse drug reactions. Therefore, careful management based on medical history as well as avoidance of unjustified treatment methods, e.g. diet therapy or immunotherapy, are necessary. This is of great importance as the incidence of food allergies is expected to increase mainly due to the progressive rise in the prevalence of inhalant allergies to pollens.
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