SOJ Immunology

2

Authors: Duncan D Adams

The histocompatibility system exists for defence against viruses. It is responsible for the rejection of allograft. The immune system attempts to counter the explosive speed of viral replication by directing the defensive immune attack by cytotoxic T cells on to histocompatibility antigens on the infected cell’s surface. This enables destruction of the virus factories before the cytotoxic T cells are swamped by the myriad numbers of new virions, a thousand coming from each infected cell every 10 hours. The histocompatibility system mistakes alloantigen on grafts for virus-infected host cells that need swift destruction. For surgical transplantation, Henry Kaplan discovered that immune ablation of the recipient followed by inoculation with donor bone marrow prevents rejection of allogeneic grafts. Sykes has improved Kaplan’s technique by adding recipient bone marrow cells to the donor ones injected for reconstitution of the recipient after immune ablation. Kaplan’s technique, used on untreated pigs, should be the standard procedure for transplantation.

6

Authors: Wafa Munir Ansari, Dilshad Ahmad Khan, Omer Jamshed Khan and Farooq Ahmad Khan

Introduction: The objective was to evaluate diagnostic accuracy of high sensitivity C-reactive protein (hS CRP), Interleukin-18 (IL-18), Tumor Necrosis Factor-alpha (TNF-alpha), Interleukin-10 (IL- 10), IL-18/IL- 10 ratio and their serum cut off values for identification of Premature Coronary Artery Disease (PCAD) patients. Method: It was a diagnostic validation case-control study carried out at the Clinical Pathology Laboratories of the Army Medical College, Rawalpindi, Pakistan, from May, 2013 to Jan, 2014. Two hundred and fifty subjects aged < 45 years scheduled to undergo coronary angiography were consecutively screened. Out of these ninetyeight patients with > 70% stenosis, in at least one coronary vessel on angiography, were labeled to have PCAD. An equal number of angio-negative subjects were taken as controls from the study group. Serum IL- 10, IL- 18 and TNF alpha were measured using Enzyme Linked Immuno-sorbent Assay (ELISA), hS CRP on Immulite 1000 and serum cholesterol, Triglycerides and High Density Lipoprotein (HDL) by colorimetric methods. Statistical analysis was done using SPSS-17 and MedCalc software. Results: Total 196 subjects consisting of 98 PCAD patients and 98 angio-negative controls participated in the study. Mean ± SD age of PCAD patients was 40.7 ± 4.23yrs (89 males and 9 females) while in controls it was 35.1 ± 7.55yrs (93 males and 5 females). Serum hS CRP had highest area under curve AUC (95% confidence interval) of 0.936 (0.89- 0.97) while AUC (95% CI) of IL-18, TNF alpha and IL-10 were 0.853 (0.79-0.90), 0.731 (0.659-0.796) and 0.574 (0.497- 0.649) respectively. Sensitivity-specificity of hS CRP and IL-18 at cut off value of 3.18 pg/ml and 200pg/ml were 86%-91% and 77%-81% respectively while that of IL-18/IL-10 ratio and IL-10 at cut off values > 138.9 and > 0.3pg/ml were 68-64% and 20-100% respectively. Significant correlation was observed between hS CRP (p < 0.01), IL- 18 (p < 0.01) and TNF alpha (p < 0.05). Conclusion: hS CRP and IL-18 have the best diagnostic potential among the cytokines for detection of PCAD with high sensitivity and specificity. IL-18/IL-10 ratio had moderate significance in the diagnosis of PCAD although it correlated well with the disease burden. IL-10 had 100% specificity highlighting its role in the diagnosis of the disease but its low sensitivity is a limiting factor. Thus, hS CRP and IL-18 are promising potential biochemical parameters aiding in the clinical diagnosis of Premature Coronary Artery Disease.

10

Authors: Enas A. El-Hussieny, Amira M. Gamal Eldeen, Roba M. Talaat, Ahmed F. Tamara, Mohamed S. Salama and Na dia M. El Beih

Background: CD36 is one of the macrophage scavenger receptor that has been implicated as a key player in the pathogenesis of atherosclerosis. Aim: This study focused on the role of CD36 in coronary artery disease (CAD) and its association with proangiogenic and inflammatory mediators. Patients and Methods: We studied 100 atherosclerotic CAD patients and 100 healthy controls. All patients had angiographic evidence of stenosis ≥ 50% in at least one major coronary artery Soluble CD36 (sCD36), peripheral blood mononuclear cells (PBMCcCD36),vascular endothelial and platelet- derived growth factors (VEGF & PDGF), Tumor necrosis factor (TNF-α) and cycloxygenase-2(COX-2) were measured using enzyme-linked immunosorbent assay (ELISA). CD36 mRNA expression was measured using reverse transcriptase polymerase chain reaction (RT-PCR). Results: A significant reduction in cCD36 expression (protein and mRNA) and plasma levels of sCD36, VEGF, PDGF in CAD patients was demonstrated. In contrast, a marked elevation in the plasma level of TNF-α was observed. There was a strong inverse correlation between severity of CAD and sCD36 (r = -0.413; P < 0.001), cCD36 (r = -0.4663; P < 0.001), CD36 mRNA (r = -0.328; P < 0.01). Furthermore, CD36 was found to be positively correlated with VEGF (r = 0.446; P < 0.001) and PDGF (r = 0.287; P < 0.05), while it was negatively correlated with TNF-α (r= - 0.352; P < 0.01). Conclusion: CD36 deficiency might represent a good expression marker for the development of CAD in Egyptian patients in association with inflammatory and proangiogenic mediators. Targeting the underling mechanism of the direct and inverse association of CD36 with angiogenic and inflammatory mediators could be used in the treatment of athero-inflammatory disorders.