59. Dyserythropoietic anaemias.

1. By origin:

1. acquired;

2. hereditary.

2. By aethiology:

1. myelotoxic – due to exogenous factors (radiation, chemical agents, viruses) and endogenic (immune factors, metabolism toxic products) ones;

2. deficient – due to deficient of factors essential for erythropoiesis – vit B (especially B₁₂ and B₉, also B₆), C, A, E, proteins;

3. dysregulatory – occur as a result of erythropoiesis dysregulation (correlation disorder between erythropoietins and erythropoiesis inhibitors at renal insufficiency; bone marrow stroma injury which serves as microenvironment for haemopoietic cells;

4. delt with Er square (“bridgehead”) diminishing – at haemopoietic tissue replacement with leucosis cells, connective tissue (fibrosis), tumors metastases.

3. Dependently on essence of processes lying in the base of anaemia development: 1) erythropoiesis disorders – reasons:

1. haemopoietic cells deficiency due to their injury or replacement;

2. cells reproducing disorders (DNA resynthesis disorder);

3. erythrocytes maturation disturbances and Er exit to blood stream (non-effective erythropoiesis which is only 10-15% under physiological conditions);

2) Hb synthesis disorders – reasons:

1. iron deficiency;

2. porphyrines synthesis defects - reasons:

• hereditary enzymopathies;

• lead intoxication;

• pyridoxine deficiency;

• Hb molecules proteinic chains synthesis defects.

60. Aplastic and hypoplastic anaemias. Metaplastic anaemia. Myelophthysis.

Aplastic anaemia – blood system disease characterized by red bone marrow haemopoietic function inhibiting and expressed by Er, granulocytes and platelets formation insufficiency. Synonym – pancytopeny.

Hypoplastic anaemia – is only erythroid branch of haemopoiesis is suffered. Synonym: erythroblastophthysis.

Myelophthysis -if only granulocytes productionis injured.

Acquired anaemias reasons:

1. physical agents (ionizing radiation);

2. chemicals (benzol, lead, mercury vapours, cytostatics, levomycetin, sulphanylamides, antiepileptic drugs, mercazolyl, antihistamine, tranquillizators);

3. biological agents (hepatitis virus);

4. idiopathic anaemia – when reason is impossible to be determined (50-75% of all anaemia cases).

2 Groups of factors:

1. with obligatory myelotoxic effect:

   1. benzol;

   2. radiation;

   3. cytostatics;

   4. As inorganic derivates;

2. with facultative (non-obligatory) effect: drugs.

Hereditary hypplastic anaemia – anaemia Fankoni – autosomic-recessive disease with DNA reparation disorders. DNA non-repaired fragments are occurred under ultraviolet irradiation and chemicals action. Often acute leucosis.

2 Main pathogenetic mechanisms:

1. stem cells disorders;

2. microenvironmental cells injury.

Characteristics:

Pathogenetically	Dyserythropoietic
Aethiologically	Acquired, sometimes hereditary
By red bone marrow regeneratory ability	Hypoegeneratory or even aregeneratory
By colour index	Normochromic
By haemopoiesis type	Erythroblastic
By clinical course	Chronic

Syndromes:

1. anaemia and hypoxic syndrome delt with it;

2. haemorrhagic syndrome;

3. inflammatory processes caused by infectious agents (pneumonia, otitis, pyelitis and others).