The clinical utility of basophil activation testing in diagnosis and monitoring of allergic disease.

The basophil activation test (BAT) has become a pervasive test for allergic response through the development of flow cytometry, discovery of activation markers such as CD63 and unique markers identifying basophil granulocytes. Basophil activation test measures basophil response to allergen cross-linking IgE on between 150 and 2000 basophil granulocytes in <0.1 ml fresh blood. Dichotomous activation is assessed as the fraction of reacting basophils. In addition to clinical history, skin prick test, and specific IgE determination, BAT can be a part of the diagnostic evaluation of patients with food-, insect venom-, and drug allergy and chronic urticaria. It may be helpful in determining the clinically relevant allergen. Basophil sensitivity may be used to monitor patients on allergen immunotherapy, anti-IgE treatment or in the natural resolution of allergy. Basophil activation test may use fewer resources and be more reproducible than challenge testing. As it is less stressful for the patient and avoids severe allergic reactions, BAT ought to precede challenge testing. An important next step is to standardize BAT and make it available in diagnostic laboratories. The nature of basophil activation as an ex vivo challenge makes it a multifaceted and promising tool for the allergist. In this EAACI task force position paper, we provide an overview of the practical and technical details as well as the clinical utility of BAT in diagnosis and management of allergic diseases.

Vitamins A and D have antagonistic effects on expression of effector cytokines and gut-homing integrin in human innate lymphoid cells.

BACKGROUND: Retinoic acid (RA), the main biologically active metabolite of vitamin A, is known to promote gut homing of lymphocytes, as well as various regulatory and effector immune responses. In contrast, the active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25D3), is predominantly immunosuppressive. Little is known about the direct effects of these vitamins on the recently identified innate lymphoid cells (ILCs). OBJECTIVE: We sought to characterize the effects of RA and 1,25D3 on human ILCs. METHODS: Peripheral blood mononuclear cells were isolated from 27 non-selected blood donor buffy coats, and ILCs were sorted by FACS. ILC1, ILC2, and ILC3 cells were cultured for 5 days with RA, 1,25D3, and various cytokines known to activate ILCs (IL-2, IL-7, IL-12, thymic stromal lymphopoietin (TSLP), IL-25, and IL-33). Cytokines produced by ILCs were measured in culture supernatants, and surface receptor expression was analysed by flow cytometry. RESULTS: Retinoic acid acted synergistically with IL-2 and other activating cytokines to induce expression of the gut-homing integrin α4ß7 in ILCs, as well as production of IL-5 and IL-13 in ILC2 cells, and IFN-γ in ILC1 and ILC3 cells. Expression of integrin α4ß7 and cytokine production in ILCs stimulated with RA + IL-2 was increased at least fourfold as compared to ILCs cultured with RA or IL-2 alone. In contrast, RA completely inhibited the IL-2-induced expression of cutaneous lymphocyte antigen (CLA) in ILCs. Moreover, addition of 1,25D3 to ILCs cultured with RA + IL-2 inhibited cytokine production and expression of integrin α4ß7 by at least 30%. CONCLUSIONS: Retinoic acid and 1,25D3 have antagonistic effects on the expression of effector cytokines and gut-homing integrin by human ILCs. The balance between these vitamins may be an important factor in the functioning of ILCs and the diseases in which ILCs are implicated, such as allergic inflammation.

Pathogen induced chemo-attractant hepoxilin A3 drives neutrophils, but not eosinophils across epithelial barriers.

Pathogen induced migration of neutrophils across mucosal epithelial barriers requires epithelial production of the chemotactic lipid mediator, hepoxilin A3 (HXA3). HXA3 is an eicosanoid derived from arachidonic acid. Although eosinophils are also capable of penetrating mucosal surfaces, eosinophilic infiltration occurs mainly during allergic processes whereas neutrophils dominate mucosal infection. Both neutrophils and eosinophils can respond to chemotactic gradients of certain eicosanoids, however, it is not known whether eosinophils respond to pathogen induced lipid mediators such as HXA3. In this study, neutrophils and eosinophils were isolated from human blood and placed on the basolateral side of polarized epithelial monolayers grown on permeable Transwell filters and challenged by various chemotactic gradients of distinct lipid mediators. We observed that both cell populations migrated across epithelial monolayers in response to a leukotriene B4 (LTB4) gradient, whereas only eosinophils migrated toward a prostaglandin D2 (PGD2) gradient. Interestingly, while pathogen induced neutrophil trans-epithelial migration was substantial, pathogen induced eosinophil trans-epithelial migration was not observed. Further, gradients of chemotactic lipids derived from pathogen infected epithelial cells known to be enriched for HXA3 as well as purified HXA3 drove significant numbers of neutrophils across epithelial barriers, whereas eosinophils failed to respond to these gradients. These data suggest that although the eicosanoid HXA3 serves as an important neutrophil chemo-attractant at mucosal surfaces during pathogenic infection, HXA3 does not appear to exhibit chemotactic activity toward eosinophils.

Immunology in the Clinic Review Series; focus on allergies: basophils as biomarkers for assessing immune modulation.

Allergen-specific immunotherapy is an effective clinical treatment for hypersensitivity to many allergens. Studies of basophils during immunotherapy have provided insight into underlying immune mechanisms and support the potential use of basophil activation as a biomarker of clinical outcomes. This review examines the evidence for different pathways of basophil modulation associated with various forms of immunotherapy. Better understanding the molecular mechanisms of basophil activation and desensitization and the relationship between suppression of these effector cells to clinical outcomes holds promise for further development and improvement in potential therapies for allergic diseases.

Resistance mechanism in rice to the midge Orseolia oryzae (Diptera: Cecidomyiidae).

The midge Orseolia oryzae (Wood-Mason) (Diptera: Cecidomyiidae) is a major and endemic pest throughout Asia. The pest is difficult to manage in view of a mixture of biotypes co-occurring in the same location and showing variable response to cultivated rice, Oryza sativa L., varieties and differentials. To develop an understanding of the resistance mechanism(s), studies were initiated during wet 2005 and 2006 in Coastal Karnataka. Antibiosis was the predominant resistance category. The maggots survived but as first instar only on all the resistant genotypes. On susceptible genotypes, larvae reached second instar at 7 d after release, third instar at 14 d after release, and pupal stage at 18 d after adult release. However, in certain resistant genotypes, maggot mortality was evident in the absence of the susceptible plant silver shoot condition. In all resistant genotypes, distinct antibiosis was observed at 14 d after adult release. Antixenosis was evident in few genotypes. So, the midge resistance in rice is manifested as a mixture of antixenosis and antibiosis. Estimation of biochemical constituents in rice shoot apices of selected resistant genotypes revealed higher levels of total phenols and total free amino acids compared with susceptible genotypes. But, the amount of total sugars, reducing sugars, crude proteins, and amino acids were not related to resistance. Biochemical profiles in relation to midge infestation showed increased phenol and decreased proline and indole acetic acid content in the growing apical meristem of resistant genotypes compared with susceptible genotypes.

Studies on water quality and zooplankton community of the Panchganga river in Kolhapur city.

The present investigation deals with the zooplanktons together with water quality of Panchganga river, in Kolhapur city, Maharashtra. This investigation was undertaken fora period of one year. The river Panchganga is a highly contaminated downstream with untreated sewage and industrial effluents, while flowing through Kolhapur city. The high value of CO2, BOD, COD, phosphate, nitrate, Zn, Fe, Cu and low value of DO at discharge zone indicates increase in organic pollution as we go down the river strech Site III and Site IV. The discharge zone is dominated by pollution tolerant zooplankton species such as Brachionus, rotifera, Brachionus keratella, Filinia, Anuraeopsis etc.

Laparoscopic cholecystectomy in India.

The first 100 cases of laparoscopic cholecystectomy carried out in a "developing country" are studied. There were 77 females and 23 males. The mean age was 48 years (24-82 years). There was no mortality and 2% morbidity. The mean operative time was two hours and 15 minutes in the first 50 cases, one hour and 50 minutes in the subsequent 50. Twelve cases were converted to open surgery, nine within the first 50 cases, three in the subsequent 50. In developing countries the challenge of financial constraints as also a different spectrum of abdominal pathology calls for greater efforts of innovation and improvization. However, the rewards of laparoscopic cholecystectomy as compared to open cholecystectomy are significant in developing countries in terms of shorter hospitalisation (3.6 vs. 13 days), early return to work (12 vs. 36 days), better hospital bed utilization, and reduced expense.