Skip to main content

Haematology summray 9


Chapter 9 in Haematology (White cells: lymphocytes) summary

-Lymophcytes are immunologically comptent white cells that are involved in antibody production  (B cells) and with the body's defence against viral infection or other foreign invasion (T cells).

-They arise from haemopoietic stem cells in the marrow, T cells being subseqently processed in the thymus.

-B cells secrete gammaglobulin antibodies specific for individual antigens.T lymphocytes are further subdivided into helper (CD4+) and cytotoxic (CD8+)cells .They recognise peptides on HLA atigens.Natural killer cells are cytoxic CD8+ cells that kill target cells with low expression of HLA molecules.

-The immune response occurs in the germinal centre of lymph nodes and involves B-cell and T-cell proliferation, somatic mutation, selection od cells by recognition of antigen on antigen-presenting cells and formation of plasma cells (which secrete immunoglobulin)or memory B cells.

-Immunoglobulins includes five subcalsses or isotypes, igG,igA,igM,igD, all madeup of two heavy chains and two light chains .

-Complement is a cascade of plasma proteins that can either lyse cells or coat (opsonise)them so they are phagocytosed.

-Lymphcytosis is usually caused by acute or chronic infection or by lymphoid leukaemias or lymphomas.

-Lymphadenopathy may be localizaed (bacause of local infection or malignancy) or generalized becaused of infection, non-infectious inflammatory diseases, malignancy or drugs.

 

 

From book: Essentail Haematology A.V.HOFFBRAND,P.A.H.MOSS.6EDITION
Labels:

Comments

Post a Comment

Popular posts from this blog

viruses

Viruses -Virus : obligate intracellular parasites . -Virus contain two genomes DNA or RNA But not both . which contain :- ss : single stranded . ds : double stranded -Capsid :- protein shell that enclose the viral genome . -Capsid symmetry : (( cabic – helical – complex )) -Viral Enveloped : help in infect host and composed of lipid bilayer and glycoprotein -Bacterophage :- viruses that infect bacteria cell ( prokaryotic ) -Virion :- complete virus particle : nuclic acid + protein . it is extracellular phase of virus (( before virus enter host cell )) -Vector virus passed from host to host through direct contact and vector . -Nucleocapsid :- viral nucleic acid + protein coat . -Viroids : is naked circular single strand RNA that infect plants . it is the smallest known pathogens . -Prions :- is infectious proteins cause brain disease e.g :- mad cow and CJD in human . -DNA viruses replicate in nucleus of host except " poxvirus " ...
1 comment
Read more

Haematology summary 18

  Chapter 18 in haematology (chroinc lymphoid leukaemias)summary -Chronic lymphocytic leukaemiaes are characterized by the accumulation of mature B or T lymphocytes in the blood. -Individual subtypes are distinguished on the basis of morphology,immunophenotype and cytogenetics. -Chronic lymphocytic leukaemia (CLL,B cell) represents 90% of cases and has a peak incidece between 60 and 80 years of age .There is genetic predisposition to development of the disease. -Most cases are indenified when a routine blood test is performed the patient can develope enlarged lymph nodes ,splenomegaly and hepatomegaly. -Immunosuppression is asignificant problem because of hypogammaglobuilaemia and cellular immune dysfunction. -Anaemia may also develop because of autoimmune haemolysis and bone marrow in filtration. -Diagnosis is usually performed by immuophenotypic analysis of peripheral blood which reveals aclonal population of CD5 + ,CD23 + B cells. -The best gu...
2 comments
Read more

Haematology summary 16

Chapter 16 in haematology (Myelodysplasia)summary -Myelodysplasia include a group of clonal disorders of heamopoietic stem cells that lead to bone marrow failure and low blood cell counts.Ahallmark of the disease is simultaneous proliferation and apoptosis is haemopoietic cells leading to the paradox of a hypercellular bone marrow but pancytopenia in peripheral blood . there is a tendency to progress to acute myeloid leukaemia. -In most cases, the disease is primary but it may be secondary to chemotherapy given for treatment of another malignancy. -The main clinical features of anaemia, infectionand bleeding, are caused by reduction in the bone count.most patients are over 70 years of age. -Diagnosis is made by examination of the blood and bone marrow together with genetic studies of the tumour cells . they are calssfiedinto eight major subtypes. -Scoring systems can divide patients in those with low-grade or high-grade disease . -Low-grade disease may not nee...
Post a Comment
Read more