Hand out sheet - Faculty of Medicine - มหาวิทยาลัยนเรศวร

12/4/2012Figure 5-34 Clinical course of HIV infection. During the early period after primary infection, there is widespread dissemination of virus anda sharp decrease in the number of CD4+ T cells in peripheral blood. An immune response to HIV ensues, with a decrease in viremiafollowed by a prolonged period of clinical latency. During this period, viral replication continues. The CD4+ T-cell count graduallydecreases during the subsequent years, until it reaches a critical level below which there is a substantial risk of opportunistic diseases.(Redrawn from Fauci AS, Lane I-IC: Human immunodeficiency virus disease: AIDS and related conditions. In Fauci AS, et al (eds):Harrison's Principles of Internal Medicine, 14th ed. New York, McGraw-Hill, 1997, p 1791. Reproduced with permission of The McGraw-Hill Companies.)Downloaded from: StudentConsult © (on 2005 3 December Elsevier 2009 12:14 AM)Hypersensitivity reactions• ภาวะภูมิไวเกิน = Hypersensitivity Reactions (4 types)– Type I : Allergy and Anaphylaxis(IgE – mast cell/basophil)– Type II : Antibody Dependent(IgG/IgM – membrane/tissue antigen)– Type III : Immune Complex – Mediated(antigen – antibody complex)– Type IV : Cell – Mediated(T lymphocytes – APCs)Pasuporn Po‐ngernnakTypeType I Hypersensitivity•Immediate hypersensitivityHistopathologic Lesions•Vascular dilation, edema, smooth musclecontraction, mucus production, tissueinjury, inflammationImmune Mechanisms• Production of IgE antibody → immediaterelease of vasoactive amines and othermediators from mast cells; laterrecruitment of inflammatory cellsPrototypical Disorders• Anaphylaxis; allergies; bronchial asthma(atopic forms)Pasuporn Po‐ngernnakType I HypersensitivityActionVasodilation,increased vascularpermeabilitySmooth musclespasmCellular infiltrationMast cell MediatorsHistaminePAFLeukotrienes C 4 , D 4 , E 4Neutral proteases thatactivate complement andkininsProstaglandin D 2Leukotrienes C 4 , D 4 , E 4HistamineProstaglandinsPAFCytokines (e.g.,chemokines, TNF)Leukotriene B 4Eosinophil and neutrophilchemotactic factors (notdefined biochemically)Pasuporn Po‐ngernnak14