House dust mite allergy and shrimp allergy: a complex interaction

Summary

Background and Objective. Sensitization and allergy to shrimp among Italian house dust mite allergic patients are not well defined and were investigated in a large multicenter study. Methods. Shrimp sensitization and allergy were assessed in 526 house dust mite (HDM)-allergic patients submitted to the detection of IgE to Der p 10 and 100 atopic control not sensitized to HDM. Results. Shrimp allergy occurred in 9% of patients (vs 0% of 100 atopic controls not sensitized to HDM; p minor 0.001). Shrimp-allergic patients were less frequently hypersensitive to airborne allergens other than HDM than crustacean-tolerant subjects (35% vs 58.8%; p minor 0.005). Only 51% of tropomyosin-sensitized patients had shrimp allergy, and these showed significantly higher Der p 10 IgE levels than shrimp-tolerant ones (mean 22.2 KU/l vs 6.2 KU/l; p minor 0.05). Altogether 53% of shrimp-allergic patients did not react against tropomyosin. Conclusions. Shrimp allergy seems to occur uniquely in association with hypersensitivity to HDM allergens and tropomyosin is the main shrimp allergen but not a major one, at least in Italy. Along with tropomyosin-specific IgE levels, monosensitization to HDM seems to represent a risk factor for the development of shrimp allergy among HDM allergic patients.

The automation of sediment urinalysis using a new urine flow cytometer (UF-100)

The UF-100 analyser is a fully automated instrument that stains the DNA and the membranes of the formed elements in native urine. The sample then passes as a laminar flow through a laser beam and light scattering, fluorescence and impedance are measured. The main purpose of the present work was to assess the analytical performance and the accuracy of the measurements of the UF-100 analyser. No carryover was observed, while the linearity was higher then the upper limit (40000 total particles microl(-1)) suggested by the manufacturer. The within-run imprecision was low, ranging from 17.7 % to 2.4% and was up to threefold better than manual microscopy. Comparison of results obtained by sediment microscopy (performed according to National Committee for Clinical Laboratory Standards (NCCLS) recommendations) and by the UF-100 analyser showed a linear correlation with r = 0.833 for erythrocytes, r = 0.934 for leukocytes, r = 0.880 for epithelial cells and r = 0.40 for casts. To evaluate the reliability of the UF-100 analyser in detecting bacteria we compared the results with the microbial culture (n = 608). Using a cut-off value of bacterial count above 1800 degrees l(-1) and at leukocyte count above 45 microl(-1), the analyser detected positive cultures with a sensitivity of 87 % and a specificity of 80 %. In conclusion, the UF-100 analyser can improve the work flow, increasing the output of urinalysis by reducing the number of specimens submitted for microscopy. Also the method provides reliable information for the identification of urinary tract inflammation and bacterial infection.

Sub-Golgi distribution in rat liver of CMP-NeuAc GM3- and CMP-NeuAc:GT1b alpha 2----8sialyltransferases and comparison with the distribution of the other glycosyltransferase activities involved in ganglioside biosynthesis

Using a sucrose density gradient fractionation of a highly purified Golgi apparatus from rat liver, we determined the sub-Golgi distribution of CMP-NeuAc:GM3 ganglioside alpha 2----8sialyltransferase (GM3-SAT) and CMP-NeuAc:GT1b ganglioside alpha 2----8sialyltransferase (GT1b-SAT), in comparison with that of the other glycosyltransferase activities involved in ganglioside biosynthesis. While GM3-SAT was recovered in several density fractions, GT1b-SAT was mainly found on less dense sub-Golgi membranes; this indicates that these two activities are physically separate. Moreover, with regard to the monosialo pathway, CMP-NeuAc:lactosylceramide alpha 2----3sialyltransferase, UDP-GalNAc:GM3 ganglioside beta 1----4N-acetylgalactosaminyltransferase, UDP-Gal:GM2 ganglioside beta 1----3galactosyltransferase, and CMP-NeuAc:GM1 ganglioside alpha 2----3sialyltransferase were resolved from more dense to less dense fractions, respectively. In the disialo pathway, UDP-GalNAc:GD3 ganglioside beta 1----4N-acetylgalactosaminyltransferase, UDP-Gal:GD2 ganglioside beta 1----3galactosyltransferase and CMP-NeuAc:GD1b ganglioside alpha 2----3sialyltransferase co-distributed with the corresponding activities of the monosialo pathway. These last results indicate that many Golgi glycosyltransferases involved in ganglioside biosynthesis are localized in the order in which they act.