[CROATIAN GUIDELINES FOR IN VITRO DIAGNOSIS OF IgE MEDIATED HYPERSENSITIVITY].

In vitro diagnostic procedure in allergology includes determination of serum levels of total and allergen specific IgE antibodies, allergen specific IgG antibodies, plasma tryptase, eosinophil cationic protein (ECP) and basophil activation test (BAT). In vitro tests should be used according to clinical history, physical examination, and in vivo methods for allergy testing. Clinical relevance of elevated total IgE in allergy diagnosis is modest, since it can be caused by other conditions. Elevated serum levels of allergen specific IgE antibodies, together with positive medical history, are indicative of clinically relevant allergy. A recommended laboratory method for total and specific IgE concentration measurement is the sandwich-type fluoroimmunoassay ImmunoCAP, considered as an ideal immunoassay. Serum levels of allergen specific IgG antibodies have no proved clinical relevance in food allergy diagnosis. They can be useful to monitor venom immunotherapy success, as well as to estimate the risk of venom induced anaphylaxis. Elevated plasma tryptase (subtype ß) level is an indication of mast cell activation caused by specific allergen. It should be obtained within 4 hours after an anaphylactic episode. Elevated level of ECP can be detected in patient blood during late phase of allergic reaction. It can be used to monitor patients with chronic allergenic and inflammatory conditions in which eosinophils play a central role. BAT includes measurement of CD 63 (cluster of differentiation) and CD 203 antigens of the molecular surface by flow cytometry. It is useful in the diagnosis of venom, food and drug allergy, estimation of severity of allergic disease and natural tolerance to allergens. In vitro tests based on allergen extracts can be used for in vitro diagnosis in monosensitized patients with clear medical history and symptomatic treatment. Molecular allergy diagnosis should be performed in special clinical indications such as diagnosis of cross reactivity, prescription of specific immunotherapy (especially in polysensitized patients with complex symptoms), diagnosis of idiopathic or cofactor induced anaphylaxis, latex allergy, and assessment of the risk of allergic reaction to specific allergen.

Transient hyperphosphatasemia in an infant with bronchiolitis and pneumonia.

We present a case of benign transient hyperphosphatasemia in a 4-month-old infant with acute bronchiolitis and pneumonia. During hospitalization the infant had an increased catalytic activity of alkaline phosphatase (ALP): day 2, 5074 U/L; day 3, 5622-U/L; and day 8, 3129 U/L. The x-ray, leukocytosis, and C-reactive protein findings pointed to bacterial etiology of the respiratory disorder. Electrophoretic separation revealed an atypical isoenzyme profile: fast anodal, near-cathodal and bone fractions. ALP levels normalized within 54 days, and control electrophoresis indicated normal liver, placental/placental-like, intestinal and bone isoenzymes. The appearance of atypical fast anodal and near-cathodal fractions of ALP in this infant during the course of acute lower respiratory tract infection and rapid return to the reference intervals pointed to benign transient hyperphosphatasemia.

Lipoprotein lipase gene polymorphism and lipid profile in patients with hypertriglyceridemia.

AIM: To assess lipid profile and the genotype distribution of lipoprotein lipase gene polymorphism at Pvu II polymorphic site within the intron between exons 6 and 7 in patients with hypertriglyceridemia. METHODS: Pvu II polymorphism was determined in 116 hypertriglyceridemic patients and 50 normolipidemic controls from Zagreb, Croatia. DNA was extracted from peripheral blood mononuclear cells. Polymerase chain reaction was used for amplification of 6th intron, which was then restricted with Pvu II-restriction endonuclease. Serum lipid and lipoprotein fractions were determined by standard enzymatic methods. Cholesterol concentrations in HDL subfractions, HDL2 and HDL3, were determined after precipitation with polyethyleneglycol. Apolipoproteins (apo) A-I and B were determined by immunonephelometry. RESULTS: Triglycerides showed a positive correlation with total cholesterol (r=0.222, 95% CI=0.041-0.389, p=0.017) and inverse correlation with HDL-cholesterol (r= -0.278, 95% CI= -0.449 to -0.088, p=0.005), especially with HDL3-cholesterol (r= -0.333, 95% CI= -0.497 to -0.147, p=0.001). The respective frequencies for genotypes /, +/, and +/+ were 22, 58, and 36 in the patient group, and 17, 17, and 16 in the control group. Serum triglycerides in the patient group, expressed as median in mmol/L, were 3.30 (range, 2.60-10.90), 3.60 (range, 2.50-21.50), and 3.99 (range, 2.50-15.56), respectively. Serum concentration of triglycerides differed significantly between the +/+ and / genotype (p=0.043). CONCLUSION: There is an association between genetic variation at the locus for lipoprotein lipase and high serum triglyceride levels. This might prove useful in the detection of individuals susceptible to the development of hypertriglyceridemia, as well as a marker in the analysis of this genetic defect in patient families.