sarcoid - SARCOIDOSIS Current Controversies & Update of...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Current Controversies & Update of Sarcoidosis SARCOIDOSIS • Multisystem granulomatous disorder of unknown origin characterized by activation of T-Lymphocytes and mononuclear phagocytes at sites of disease. • Most commonly affects Lungs & Intra-thoracic lymph nodes. • Diagnosis is securely established from compatible history, histology Non- caseating granulomas in more than one organ & absence of competing Dx like TB\Fungal Disease\ Malignancy. PATHOGENESIS : Antigen Triggered : Evidence : 1. T-cell Ag receptors (TCR) monoclonal. 2. in mRNA for TCR. Genetic Susceptibility : Data from monozygotic twins who do not live in same environment, prevalence of disease in siblings of affected individual suggest genetic involvement. Not a single gene disease. Multiple genes interact with one or more environmental triggers to provoke first phases of disease. EVIDENCE Racial Difference : Scandinavians with African – American have highest prevalence. Latin Americans higher prevalence than white people. Familial Sarcoidosis : RR for Sarcoidosis in siblings of affected individual was 36-73 (McGrath DS et al Thorax 2000 ; 55 : 751-4) Odd’s Ratio of familial disease from ACCESS study was 5.8. Inference : Familial sarcodosis present in majority of population. Family members of sarcoidosis cases have several fold increased risk of disease compared with general population.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 Key Candidate Genes : MHC HLA class I bind endogenous antigen peptides and present than to CD8 + cells. HLA Class II bind peptides from exogenous antigens & present them to CD4 + cells. MHC Class I : HLA B7 ass. with high prevalence of sarcodosis in African- Americans, HLA B8 ass. With ac. Onset and short duration. MHC class II : Japanese pts. : HLA DR5, -DR8, -DR9 alleles Germans : HLA-DR5 ass. With chr. Disease DR3 ass. With acute disease. Scandinavian study : HLA-DR3 ac. onset and short duration. HLA-DR 14, DR 15 chr. Disease. CAUSE OF SARCODOSIS Sarcoid granulomas are formed in response to a persistent, poorly degradable antigenic stimulus. Non-infective agents : Pine Pollen, Clay soil, talc, beryllium, ziroconium. None of these theories have endured. Infective : Evidence Supporting : 1. Seasonal Variation : Ac. Onset with erythema nodosum and arthralgia peak in spring months seen in Sweden / Greece/Spain/ New Zealand 2. Clustering : • Hill SE (Thorax 1987 : 42 : 427-30) noted time space clustering. • Cases whose place of residence during an infective period of 5 yrs. Before and 2 yrs. After the DX were separated by distance of <100 m. • Communicable agent was likely the major causative factor in the disease. • Edmondstone WM (Thorax 1988 ; 43 : 342-3) 7.5 times greater number of nurses with the condition than expected. • Individuals in close proximity to sarcoidosis cases may be at a higher risk of disease, possibly due to a transmissible agent.
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 12/03/2011 for the course MEDICINE 350 taught by Professor Dr.aslam during the Winter '07 term at Medical College.

Page1 / 16

sarcoid - SARCOIDOSIS Current Controversies & Update of...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online