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

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 guide
2 comments
Read more

Haematology summary 19

Chapter 19 in haematology (Hodgkin lymphoma)summary -Lymphoma are a group of diseases caused by malignant lymphocytes that accumulation in lymph nodes and cause lymphoadenopathy. -The major subdivision of lymphomas ia into hodgkin and this is based on the presence of Reed-strenberg cells in hodgkin lymphoma. -Reed-strenberg cells are neoplastic B cells but most cells i the lymph node are reactive inflammatory cells. -The usual clinical presentation is with painless asymmetrical lymphadenopathy- most commonly in the neck. -Constitutional symptoms of fever,weight loss and sweating are prominent in patients with widespresd disease. -Blood tests may show anaemia, neutophilia and rasied erythrocyte sedmentation rate (ESR) or lactic dehydrogenase (LDH). -Diagnosis is made by histological examination of an excised lymph node and there are four subtype of disease . -Staging of the disease is important for determining treatment and prognosis history, examiantion
Post a Comment
Read more

Haematology summary 17

Chapter 17 in haematology (Acute lymphoblastic leukaemia)summary -Acute lymphoblastic leukaemia (ALL) is casued by an accumulation of lymphoblasts in the bone marrow. It isthe most common malignant disease of clidhood-75% of cases occur before the age of 6 years. Eighlty-five per cent of cases are of B-cell lineage with the rest being of T-cell lineage. -The first genetic mutation ocuurs in amy cases in utero , with a secondary genetic event occuring later inclidhood,possibly as a reaction to an infection. -The clinical presentation is with the features of bone marrow failure (anaemia,infection and bleeding) together with symptoms of tissue infiltration by tumour cells, leading to bone pain or swollen lymph nodes. -Diagnosis is by examination of blood and bone marrow.important tests include microscopic examination of the tumour cells, immunophenotyping and genetic analysis. -ALL is subclassified according to the underlying genetic defect and a wide varity of genet
Post a Comment
Read more