1 / 18

MLAB 1415- Hematology Keri Brophy-Martinez

MLAB 1415- Hematology Keri Brophy-Martinez. Chapter 20: Nonmalignant Lymphocyte Disorders. Review. Lymphs originate primarily from bone marrow and thymus Secondary organs include spleen, lymph nodes, tonsils, and Peyer’s patches in GI tract. Review. 3 general populations B- lymphs: 10-20 %

yvon
Download Presentation

MLAB 1415- Hematology Keri Brophy-Martinez

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. MLAB 1415- HematologyKeri Brophy-Martinez Chapter 20: Nonmalignant Lymphocyte Disorders

  2. Review • Lymphs originate primarily from bone marrow and thymus • Secondary organs include spleen, lymph nodes, tonsils, and Peyer’s patches in GI tract

  3. Review • 3 general populations • B- lymphs: 10-20 % • T-lymphs: 60-80% • NK: < 10% Pluripotent Stem cell Lymphocyte Stem cell B-cell T-cell

  4. Characteristic Cell • Reactive lymphocyte - transformed or benign lymph • Familiar terms are immunocytes, transformed lymph, immunoblast, plasmacytoid, Downey cell • Why causes them? • Virus attaches to the B- lymphocyte and infects it • This binding “activates” the lymphocyte causing it to express an activation marker (CD23) • CD23 is the receptor for the B-lymph growth factor • Once the virus is inside the cell, it incorporates itself into the B-cell genome to make more viral proteins, and keep passing itself on to future B-lymphs

  5. Cell Characterisitcs

  6. Introduction • Majority of disorders affecting lymphocytes are acquired • Hallmark: reactive lymphocytosis • Reactive process • Congenital disorders • Defect is found within lymphocytic system

  7. Introduction • Important to differenciate benign conditions associated with lymphocytosis from malignant lymphoproliferative disorders • How? • Presence of reactive lymphs • Positive serological test for antibodies against infectious organisms • Absence of anemia and thrombocytopenia • All of above favor a benign diagnosis

  8. Lymphocytosis • Excess of lymphocytes in the blood. • Absolute lymphocyte count (ALC) > 4.8 x 109 /L in adults • Relative count > 35-45% • Self-limited • Reactive process is due to infection or inflammatory conditions • B and T cells involved • Lymphocytes develop in response to antigenic stimulation. They become “activated”

  9. Causes of Reactive Lymphocytosis • Infectious mononucleosis (IM) • Caused by the Epstein-Barr Virus (EBV) which enters the body via saliva (“kissing disease”) • Clinical symptoms • Classic triad: fever, pharyngitis and lymphadenpathy • Dysphagia • General malaise • Fatigue • Spleen is enlarged and nodes are firm but not tender or warm • Generally seen in children and young adults (17-25 yrs old)

  10. Lab features of IM • CBC • Relative lymphocytosis • Peaks at 2-3 weeks of infection, remains elevated for 2-8 weeks • Leukocyte count 12-25 x 109/L • Peripheral smear • Typical lymphocyte is historically referred to as a Downey cell with irregular cytoplasmic border, increased cytoplasm and dark blue edge around the periphery of the cytoplasm. • >20% reactive lymphs • Serologic test • Heterophil antibody test (i.eMonospot)

  11. Causes of Reactive Lymphocytosis • Toxoplasmosis • Infection with intracellular protozoan Toxoplasma gondii • Acquired infections in children and adults due to ingestion of oocysts from cat feces or undercooked meat • Can be transmitted via placenta

  12. Causes of Reactive Lymphocytosis • Cytomegalovirus (CMV) Infection • Belongs to herpes family • Endemic worldwide • Acquired through transfusions, sexual contact and close contact • Can be transmitted across placenta • Poor prognosis for immunocompromised individuals who contract virus

  13. Causes of Reactive Lymphocytosis • Infectious lymphocytosis • Affects children • Viruses include adenovirus, coxsackie A and Bordetella pertussis • Leukocytosis and lymphocytosis occur in first week of illness then return to normal

  14. Lymphocytopenia • Absolute lymphocyte count< 1.0 x 109/L • Causes • Decreased production or increased destruction of lymphocytes • Changes in lymphocyte circulation patterns • Other unknown causes • Refer to page 411, table 20-4

  15. Immune Deficiency Disorders • Impaired function of one or more of the components of the immune system: T, B, or NK lymphocytes • Body unable to mount an adaptive immune response • Can be acquired or congenital

  16. Acquired Deficiencies • Acquired immune deficiency syndrome (AIDS) • Infection with a retrovirus, human immunodeficiency virus type-1 (HIV-1) • Transmission through sexual contact or contact with blood and/or blood products

  17. Congenital Deficiencies • Decrease in lymphocytes and impairment in either cell-mediated immunity (Tcells), humoral immunity(Bcells) or both • Lymphocytes appear normal on ps

  18. Congenital Deficiencies • Severe Combined immunodeficiency Syndrome • Major qualitative immune defects involving both humoral and cellular immune functions • Wiskott-Aldrich Syndrome • Patients have recurrent infections due to immunodeficiency, thrombocytopenia and eczema

More Related