A low count of CD4 + and CD8 + lymphocytes is a hallmark laboratory finding in the coronavirus disease 2019 (COVID-19). Using flow cytometry, we observed significantly higher CD95 (Fas) and PD-1 expression on both CD4 + T and CD8 + T cells in 42 COVID-19 patients when compared to controls. Higher CD95 expression in CD4 + cells correlated with lower CD4 + counts. A higher expression of CD95 in CD4 + and CD8 + lymphocytes correlated with a lower percentage of naive events. Our results might suggest a shift to antigen-activated T cells, expressing molecules increasing their propensity to apoptosis and exhaustion during COVID-19 infection.

Quantitation of neutrophil CD64 expression and procalcitonin (PCT) levels in blood samples have been recently proposed as useful tools for early detection of sepsis. To determine the usefulness of these tests, we analyzed blood samples of 112 patients, admitted to an intensive care unit (ICU), presenting clinical symptoms of sepsis, as well as of 50 healthy controls. At the end of the study, a retrospective analysis showed that only 52 ofthe 112 ICU-patients presented a real sepsis (positive blood culture). The results obtained indicated that of the 52 patients with sepsis, 50 and 49 presented levels of neutrophil CD64 expression~2398 molecules per cell (cut-off determined by receiver operator characteristic analysis) and PCT levels> 0.5 ng/ml (cut-off suggested by the manufacturer), respectively. However, the neutrophil CD64 test showed higher specificity in detecting sepsis since 5 out of the 60 ICU-patients without sepsis (negative blood culture), presented CD64 expression levels~2398 molecules per cell, PCT levels~0.5 ng/ml were shown in 27 patients. Moreover, while none of the 50 healthy controls presented a neutrophil CD64 level higher than the cut-off value, 5 patients presented PCT levels~0.5 ng/ml. In conclusion, our data seem to indicate that the quantitation of CD64 expression could be taken into consideration as a sensitive and specific test for early diagnosis of sepsis.

Using flow cytometry, food allergen-specific basophil responses could be monitored in order to identify an acquired tolerance induced by desensitization treatment. Although further studies are needed to develop this important new topic, it was interesting to note that the BAT seemed to be more sensitive and characterized by a close correlation with clinical tolerance.

IntroductionLipid transfer proteins (LTP), profilin and PR-10 are the most important panallergens in central and southern Italy. Lipid transfer proteins are stable molecules, predominantly present in the fruit peel, which can induce systemic symptoms after ingestion of vegetables. Profilin and PR-10 are randomly distributed in the pulp and peel. Both are labile proteins and usually determine reactions restricted to the oral cavity. Panallergens-specific IgE may cross-react with homologues from different plant sources, due to their conserved structure.AimTo assess the pattern of sensitization to panallergens and the correlation with the clinical history and the allergological evaluation of food and aeroallergens.Material and methodsOne hundred and twenty patients with adverse reactions after vegetables ingestion underwent skin prick tests (SPT) with commercial extracts of plant-derived foods and inhalant allergens and commercial extracts of LTP, profilin and PR-10.ResultsMany patients presented positive SPT with different plant-food allergens. We found that 76 patients were sensitized to LTP, 14 to profilin and 5 to PR-10. In the LTP-sensitized group, 64 (84%) patients suffered from systemic symptoms while the patients sensitized only to profilin referred the oral allergy syndrome.ConclusionsThis study shows a high rate of sensitization to LTP in our population according to the literature about food allergy in our geographical area and confirms the literature data about the symptoms referred by patients with sensitization to panallergens. Panallergens should be considered as clinically relevant food allergens.