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HEMATOLOGY

Hematopoiesis

Fetus: liver, spleen, bones

sometimes regain heatopoietic activity in the adult: i.e. myelofibrosis

Child: long bones, skull, vertebrae etc.

Adult: vertebrae, sternum, ribs, pelvic bones

and long bones, skull - about 1 kg tissue

producing 1011 cells/day

Hematopoietic cells

Pluripotent stem cell compartment

–relatively small, lymphocyte-like cells

Proliferating cells of committed lineage

myeloid, erythroid, megakaryocyte, lymphoid,

reticulum cell lines

(normal myeloid to erythroid ratio in the b.m. : 2-3:1)

Maturing (postmitotic) cells

Mature cells

circulating half life: pmn.leukocytes 6 hours

platelets: 8-10 days

erythroid cells: 120 days

Erythropoiesis

Stimulus: hypoxia erythropoietin

(in the kidney [and in the liver])

pluripotent stem cells

CFU-E

BFU-E

proerythroblasts

erythroblasts

normoblasts

mature red blood cells

Leukocyte production

Pluripotent stem cells

Myeloblasts (committed stem cells: CFU-C CFU-GM, stimulated by CSF-s)

Promyelocytes largest leukocytes, with non specific

granulation

Myelocytes specific granulation (Neu.,Eo., Bas.)

last proliferating cells

Metamyelocytes

Band-form

Mature polymorphonuclear granulocytes

Megakaryocyte line

Giant, multinucleated cells

Breaks up, releasing about 5000 platelets

Marrow lymphocytes

arising also in spleen and lymph nodes

lifetime: years

Bone marrow function

Haematopoiesis

Antibody producing plasma cell differentiation

Monitoring hematopoietic cell quality

Important key nutrients: iron

folic acid

vitamin B12

regulatory hormones

(EPO, CSF-s)

interleukins

Anemia

Decrease in red cell mass or hemoglobin content of blood below the physiologic need

Not a disease itself! A clinical sign!

Analysis of anaemia

–seek the background mechanisms

loss of red blood cell - bleeding

lack of red blood cell production

excessive red blood cell damage

–identify the cause of anaemia

–morphological evaluation

History

Family history: anemia, splenomegaly, jaundice

Bleeding tendency in the family

Diet, alcohol intake

Menorrhagia (number of used tampons)

Drugs

Chronic diseases

Malnutrition, malabsorption

Transfusion, iron or other therapy against anemia

Anemia

Signs and symptoms vary with the rapidity of onset:

Rapid (bleeding or brisk hemolysis)

–cardiovascular compensatory reactions:

tachycardia, postural hypotension, vasoconstriction

in the skin and extremities, dyspnea on exertion,

faintness, even shock

Slowly developing anemias (ie.nutritional deficiency, chr.bleeding, hemolysis etc.)

–there is time for compensation

–the patient remains asymptomatic for a long time

Anemia

Mild: often asymptomatic

Moderate: symptoms on exertion

Severe: symptoms on rest

heart failure

Anemia - symptoms

–fatigue

–dizziness, vertigo, headache, tinnitus

–cold intolerance

–increased irritability, difficult concentration

–sleeping disturbancies

–exertional intolerance

–abnormal menstruation, loss of libido, impotence

–Hb<75g/l : resting heart rate, stroke volume 

–dyspnea

–complaints of local vascular diseases 

(angina pectoris, cerebral ischaemia,

intermittent claudication)

Anemia - physical findings

Non cause-specific

Pallor of skin and mucous membranes

–causes: Hb and blood redistribution from the skin

–colors

greyish: malignancy

lemon-like: hemolysis, B12 deficiency

Tachycardia

Hyperkinetic precordium

Systolic murmur (reversible)

Anemia - physical findings

Cause-related

Jaundice hemolysis

Hepatopsplenomegaly - e.g.hemolysis

Lymphadenopathy - lymphomas, autoimmune diseases

Cheilosis (fissura) iron deficiency

Koilonychia (spoon-shaped nails) iron def.

Beefy red smooth tongue (Hunter-glossitis) - pernicious anemia

Neuropathy - pernicious anemia

Rectal digital examination - bleeding

Evaluation of anemia

The patient is truly anemic?

–Increased plasma volume: pregnancy, fluid overload, congestive heart failure

–Falsely elevated Hb or Htc: acute dehydration:

plasma loss in burns, vigorous diuresis, bleeding

Aquired or inherited?

Is there evidence of blood loss? (FOBT, menstruation)

Is there evidence of nutritional deficiency

or malabsorption?

Is there evidence of hemolysis?

Is there evidence for toxic exposure (drugs)

Is there „anemia of chronic disease”

chr. inflammation, renal failure, cancer

Laboratory evaluation of anemia

Complete blood picture

Red cell indices

red blood cell count F:3,9-5,6, M:4,5-6,5 G/l

hemoglobin level F:115-155 M:135-175 g/l

hematocrit F:36-48 M:40-52%

MCV: mean corpuscular volume 80-95 fl

MCH mean corpuscular hemoglobin 27-34 pg

MCHC: mean corpuscular hemoglobin concentration

300-350 g/l

Reticulocyte count (traces of endoplasmic reticulum) - good marker of erythropoiesis 0,5-1,5%

MCV

Microcytic anemia (MCV<80 fl)

iron deficiency, thalassemia, sideroblastic anemia

Normocytic anemia (MCV 80-100 fl)

acute bleeding, renal failure, aplastic anemia

Macrocytic anemia (MCV>100 fl)

vitamin B12, folic acid deficiency, liver disease, alcoholism, hypothyroidism

MCH

Hypochromic (MCH<27 pg)

–Iron deficiency(i.e. chr. beeding, malabsorption)

–chr. inflammation, malignancy, chr. infection, thalassemias,

myelodysplastic sy.

Normochromic (MCH 27-34 pg)

–acute bleeding, hemolysis, aplastic anemia, renal anemia

Hyperchromic (MCH>34 pg)

–megaloblastic anemia (B12, folic acid deficiency)

Clinical classification of anemias

Decreased cell production

–Aplastic anemia

–Myelodysplastic syndrome

–Deficiency anemias (iron, B12, folic acid)

–Erythropoietin deficiency (renal failure)

–Bone marrow suppression (malignancy, toxin,virus)

Increased red blood cell destruction/elimination

–Extrinsic factors (immun, toxins, mechanic)

–Membrane defects

–Enzyme defects

–Hemoglobinopathy

Blood loss (genitourinary, gastrointestinal, pulmonary

other bleeding)

Bone marrow investigation
Bone marrow aspiration or biopsy

bone marrow cellularity

myeloid-erythroid ratio (norm: 2-3:1)

cell maturation

bone marrow infiltration

stromal cells (fibroblasts etc.)

Polycythemias

Hyperviscosity

–Decreased cerebral blood flow

tinnitus, lightheadedness, dizziness, stroke

–Congestive heart failure

–Thrombosis

Increased cell turnover

–Gout (due to hyperuricemia)

–Itching

In polycythaemia vera

–Thrombocytosis

–Haemorrhage

Polycythemias

Primary: polycythemia vera myeloproliferative disorder

–other cell lines are affected (leukocytosis, thrombocytosis)

–hepatosplenomegaly

–EPO level: low

Secondary:

–hypoxia EPO production

chr. pulmonary diseases

morbid obesitiy (Pickwick’s syndrome)

high altitude

–EPO overproduction: tumors

Leukocyte disorders

Granulocytes (neutrophil, eosinophil basophil)

Monocytes and tissue macrophages

Lymphocytes

Functions of leukocytes

Maintaining host defences agains disease

Killing microorganisms

Digestion of tissue debris

Releasing cytokines and mediators

Activation of immune system

Neutrophil granulocytes

Functions:

chemotaxis

phagocytosis

microbial killing

Disorders

neutropenia, agranulocytosis: abs.count<1000

causes:drugs, autoimmun diseases, viral infections (e.g. EBV,HIV,hepatitis), B12 deficiency, leukemias,alcoholism

increased risk of infection

neutrophilia:infections, stress, drugs (steroids)

leukemoid reaction: 30 000-50 000 G/l with mature cells

left shift: bacterial infections

neutrophil function disorders

Mononuclear phagocytes
monoblasts, promonocytes, monocytes, tissue macrophages

Functions

chemotaxis

ingestion and killing microorganisms

secretion of several factors

proteases, cytokines, reactive oxygen compounds,

colony stimulating factors

interaction with lymphocytes

antigen processing and presentation

Eosinophil granulocytes

Eosinophilia:

Parasitic infections

Allergies

Autoimmune diseases

Hematolgic malignancies (CML, Hodgkin’s disease etc.)

Basophil granulocytes

Important role in:

–iflammation

–hypersensitivity reactions

Basophilia: malignant hematologic diseases

Acute leukemias

Agressive immature hemopoietic cell proliferation, without differentiation

Subtypes:

ALL (acute lymphoblastic leukemia)

ANLL (acute non lymphoblastic leukemia) or

AML (acute myeloblastic leukemia)

Acute leukemia syndrome

Susceptibility to infections - serious infections

Anaemia due to bone marrow infiltration and bleeding

Thrombocytopenia - bleeding tendency

purpuras, petechiae, mucosal bleeding

Organ infiltration

In ALL: lymphadenopathy, splenomegaly

Chronic leukemias

Uncontrolled expansion of premature hemopoietic cells which are able to differentiate

Subtypes:

–Chronic myelogenous leukemia (CML or CGL)

a myeloproliferative disorder

–Chronic lymphocytic leukemia (CLL)

a malignant lymphoma

CML

Abnormal blood count

Organomegaly (hepato)splenomegaly

CLL

Old patients

Blood count abnormalities

Leukocytosis

Lymphocytosis (small, mature lymphocytes)

In advanced disease: anemia, tct-penia

Generalised lymphadenopathy

Splenomegaly

Susceptibility for infections (pneumonia)

Sometimes hemolytic anemia

Immundeficiency

Evaluation of leukemias

Complete blood picture

Bone marrow investigation

Cytochemistry

Immunochemistry

Genetic alterations

chromosomal aberrations

gene anomalies

Chronic myeloproliferative disorders

Polycythemia vera

Myelofibrosis with myeloid metaplasia

Essential thrombocythemia

Chronic myelogenous leukemia

Diseases of the lymphoid system

Normal lymph nodes

–Non palpable or <1 cm, except in the inguinal region where can be 0,5-2 cm sized lymph nodes normally

–Small lymph nodes can be remain after infection

–Significant: one or more new nodes >1 cm (which can’t explain by a previously recognised cause)

–New lymph nodes in older age more significant

children more likely respond with lymphoid hyperplasia

lymphyadenopathy under 30 years: 80% beningn

over 50 years: 40% beningn

Causes of lymphadenopathy

–(1) increase in the number of benign lymphocytes and macrophages during response to antigens

–(2) infiltration by inflammatory cells in infections (lymphadenitis)

–(3) in situ proliferation of malignant lymphocytes or macrophages

–(4) infiltration of nodes by metastatic malignant cells

–(5) infiltration of lymph nodes by metabolite-laden macrophages in lipid storage diseases

Lymph node characteristics

Location

Number (single, multiple, matted together)

Size

Tenderness

Consistency (hard, rubbery, soft)

Mobility

Skin reactions above the lymph node

Lymphadenopathy- by region

–Cervical in young adult: infectious mononucleosis

–Unilateral epitrochlear : hand infections

–Bilateral epitrochlear : sarcoidosis, tularemia, syphilis

–Unilateral axillary: breast carcinoma, lymphomas, infections of the upper extremities, cat-scratch disease, brucellosis

–Bilateral inguinal: venereal infections

–Unilateral inguinal: lymphogranuloma venereum, syphilis

–Progressive inguinal lymph node enlargement without obvious infection: malignant disease.

Lymphadenopathy- by region

–Posterior cervical, occipital: scalp infections, toxoplasmosis, rubella

–Anterior auricular: infections of the eyelids and conjunctiva

–Lymphomas often involve cervical lymph nodes and occasionally involve posterior auricular and occipital nodes

–Enlarged suppurative cervical nodes: mycobacterial lymphadenitis (scrofula)

–Unilateral jugular or mandibular lymph node: lymphoma or head and neck malignancy

–Supraclavicular (always significant): metastasis from intrathoracic, breast, gastrointestinal malignancies (Virchow’s lymph node) or lymphoma

Lymphadenopathy- by region

Hilar or mediastinal

–Symptoms: cough,wheezing, hoarseness, paralysis of the diaphragm, dysphagia

–Bilateral mediastinal: lymphomas

–Unilateral hilar: metastatic carcinoma (usually lung)

–Bilateral hilar: sarcoidosis, tuberculosis, fungal infections, lymphomas

Retroperitoneal, intraabdominal: lymphomas, metastases, rarely inflammatory

(Tuberculosis can cause mesenteric lymphadenitis with large matted and sometimes calcified nodes)

Generalised: lymphomas (CLL), systemic infections (tbc),

autoimmune diseases

Lymphadenomegaly
Diagnostic evaluation

Complete blood picture

Chest x-ray

Ultrasonography (abdominal, cervical, axillar etc.)

CT-scan

Fine needle biopsy- cytology

Lymph node excision

Splenomegaly - causes

–(1) Reticuloendothelial or immune system hyperplasia

infectious diseases

immune diseases (Felty's syndrome - RA)

abnormal red blood cell destruction: hereditary spherocytosis, thalassemia, sickle cell disease

–(2) Altered splenic blood flow (congestion): hepatic cirrhosis, splenic, hepatic, or portal vein thrombosis

–(3) Malignant neoplasms:

 primarily: lymphomas

secondarily: leukemias, metastatic solid tumors

–(4) Extramedullary hematopoiesis in the spleen: myeloid metaplasia

–(5) Infiltration of the spleen with abnormal material: amyloidosis,Gaucher's disease

–(6) Space-occupying lesions of the spleen: hemangiomas, cysts

Splenomegaly

–Mild: congestive heart failure, malaria, typhoid fever, bacterial endocarditis, systemic lupus erythematosus, rheumatoid arthritis, thalassemia minor

–Moderate: hepatitis, cirrhosis, lymphomas, infectious mononucleosis, hemolytic anemias, splenic abscesses and infarcts, amyloidosis

–Massive: chronic myelocytic leukemia, myeloid metaplasia with myelofibrosis, hairy cell leukemia, Gaucher's and Niemann-Pick diseases, sarcoidosis, thalassemia major, chronic malaria, congenital syphilis, leishmaniasis, portal vein obstruction

Splenomegaly
Diagnostic evaluation

Complete blood picture

Serology (infections, autoantibodies)

Blood culture

Imaging technics (chest x-ray, ultrasonography, Doppler US, CT, MR)

Histology

Malignant lymphomas

Arise in lymph nodes or extranodal lymphoid tissue

Subtypes:

–Hodgkin’s disease

–Non Hodgkin’s lymphomas

Hodgkin’s disease

Mostly young adults

Asymptomatic lymphadenopathy

–often cervical

–mediastinal

–abdominal

Hepatomegaly, splenomegaly

Fever, night sweats, loss of weight

Diagnosis: lymph node histology

(Reed-Sternberg cells)

Staging

Staging of Hodgkin’s disease

I. Involvement of a single lymph node region (I) or single extralymphatic site (IE)

II. Involvement of two or more lymph node regions on the same side of the diaphragm (II) or solitary extralymphatic site and one or more lymph node area on the same side of the diaphragm (IIE)

III. Involvement of lymph node regions on both sides of the diaphragm, accompanied by spleen involvement (IIIS), or solitary involvement of an extralymphatic organ (IIIE)

IV. Diffuse involvement of extralymphatic sites with or without lymph node enlargement

Non Hodgkin’s lymphomas

Older patients

More diffuse lymph node involvement

General symptoms:fever, weight loss, night sweat

Frequent extralymphatic involvement

(50%: bone marrowanemia, tct-penia)

Special forms: CLL

Skin infiltration (T-cells)

MALT-lymphoma

Multiple myeloma

Multiple myeloma

Plasma cell neoplasm

Bone marrow infiltration

Monoclonal immunglobulin production

Osteolytic lesions, bone pain

Renal lesion

Coagulation disorders
Bleeding tendency, thrombosis, embolism

Factors

platelets (number, function)

coagulation factors (amount, function)

surface of the blood vessels, circulation

Bleeding - history

History of common hemostatic stresses:

gum extraction, minor surgeries

menstruation, childbirth

injuries

Family history of bleeding tendency

Bleeding

Primary hemostatic defect (platelets)

occurs immediately after trauma

from superficial sites (skin, mucous membranes, nose, rarely from gastrointestinal, genitourinary tract)

–purpuras, petechiae

–ecchymoses

bleeding time

Secondary hemostatic defect (coagulation)

delayed occurence (hours, days)

from deep sites (joints, subcutaneous tissues, muscles, retroperitoneum, body cavities, cerebrum)

–hematomas

–hemarthroses

coagulation time 

Bleeding - physical findings

From capillaries: purpuras, petechiae

small, superficial,dermal or mucosal pinpoint hemorrhages

characteristic for platelet disorders

From small arterioles and venules:

–ecchymoses subcutaneous blood collections- bruises

–hematomas deeper, palpable

–in platelet and coagulation disorders

Hemarthros - bleeding into joints

characteristic for coagulation disorders (mostly hemophilia)

leads to chronic joint deformity

Thrombosis and embolism

Virchow’s triad

–Hypercoagulability

–Circulation disturbance- congestion

–Pathological endothelial surface