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ANEMII MEGALOBLASTICE

ANEMII MEGALOBLASTICE. Frotiu de sange periferic – aspect normal. Maturatie: - reducerea dim. nucleare - hemoglobinizarea citoplasmei. Durata: 7-8 zile etapa de reticulocit: - 2 zile in maduva - 1 zi in sangele periferic.

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ANEMII MEGALOBLASTICE

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  1. ANEMII MEGALOBLASTICE

  2. Frotiu de sange periferic – aspect normal

  3. Maturatie: - reducerea dim. nucleare - hemoglobinizarea citoplasmei

  4. Durata: 7-8 zile etapa de reticulocit: - 2 zile in maduva - 1 zi in sangele periferic

  5. Reticulocitele = indicator de erotropoieza

  6. Reticulocite – coloratie supravitala (fara fixare) cu albastru cresyl

  7. Durata de viata a reticulocitelor = 3 zile - 2 zile in maduva - 1 zi in sange Numar de reti. = 0,5 – 1,5 % ( 90 000 / μl ) TIMPUL DE MATURATIE CORELAT CU HEMATOCRITUL Indice de productie ( Ip) = % Rt x Ht real x 1 Ht ideal timp de maturatie Ip > 3 = An. Hiperregenerativa Ip < 2 = An. Hiporegenerativa

  8. Indice de productie ( Ip) = % Rt x Ht real x 1 Ht ideal 2 Ip > 3 = An. Hiperregenerativa Ip < 2 = An. Hiporegenerativa

  9. ANEMIE – scaderea cant. de sange • CLASIFICARE (hemograma): - An. hipocrome microcitare - An. normocrome normocitare - An. macrocitare

  10. ANEMII MEGALOBLASTICE • Grup de boli a caror tulburare fundamentala este deficitul sintezei de ADN => afectarea celulelor cu rata mare de proliferare: precursori hematopoietici si celule epiteliale gastro-intestinale

  11. ANEMII MEGALOBLASTICE • Acidul Folic: Forma naturala: acid pteroilmonoglutamic Sursa alimentara: legume verzi, fructe ( lamai, banane, pepene ), ficat, rinichi, produse lactate Necesar: 400 μg / zi, 600 μg / zi (gravide ), 500 μg / zi (alaptare) Absortie: jejun proximal - forma monoglutamica ( F ) => FH 2 => FH4 Transport plasmatic: 6 – 20 μg / l Depozit: 5 – 20 mg ( pentru 3 luni) Rol: forma activa – tetra hidrofolat ( FH4 ) cu 2 situsuri active N5 si N10 pe care se pot atasa grupari de un atom de carbon ( formil, metil, forminino, metinil) N5 – formil FH4 = acid folinic N5 - metil FH4 = forma de transport si depozit pt FH4 Rol in sinteza bazelor azotate

  12. ANEMII MEGALOBLASTICE • Cobalamina: Structura: - porfirina ( corina) - atom de cobalt central doua forme active metabolic: - metilcobalamina - adenosilcobalamina forma de sinteza - ciancobalamina (vit B12) Sursa alimentara: carne, ficat, peste, produse lactate, oua Necesar: 2 - 5μg / zi Absortie: proteina R – stomac factorul intrinsec – duoden absortie in ileon prin receptori specifici Transport plasmatic: 200 – 900 ng /l 3 proteine specializate ( transcobalamina I, II, III ) Depozit: 2- 5 mg ( pentru 3 – 6 ani )

  13. ANEMII MEGALOBLASTICE • Cobalamina: Rol: Adenosilcobalamina: conversia METILMALONIL CoA in SUCCINIL COA glucide / acizi grasi => Acid propionic (mielotoxic) => propionil CoA => Metilmalonic CoA Metilcobalamina: conversia HOMOCISTEINEI in METIONINA reactie de metilare – donator metil FH4 Metionina => adenosilmetionina = > rol in reactiile de metilare ( acizi nucleici, histone, fosfolipide, neurotransmitatori)

  14. ANEMII MEGALOBLASTICE: Cauze 1. Deficit de folati: - dieta inadecvata - deficit de absortie - necesar crescut 2. Deficit de cobalamina: - - Deficit de absortie - cauza gastrica - cauza intestinala - insuficienta pancreatica - Dieta inadecvata 3. Anemia megaloblastica acuta: 4. Droguri: citostatice, trimethoprim, anticonvulsivante, contraceptive orale 5. Cauze ereditare: aciduria orotica, sindr. Lesh – Nyhan, A.M cu raspuns la tiamina, anemia diseritropoietica congenitala 6. Anomalii dobandite de etiologie neprecizata:Anemia megaloblastica refractara, eritroleucemia

  15. ANEMII MEGALOBLASTICE: Patogeneza Deficitul sintezei de AND => asincronism de maturatie nucleo – citoplasmatic => suferinta sistemelor celulare cu rata mare de proliferare: -> epiteliu digestiv => tulb. de troficitate -> tesut hematopoietic => hematopoieza ineficienta - hiperplazie eritroida medulara - Indice productie scazut - turnoverul Fe plasmatic crescut - scade incorporarea Fe in eritroblasti - BI / urobilinogen / LDH crescute deficit de cobalamina = > mielotoxicitate

  16. ANEMII MEGALOBLASTICE: Tablou clinic • Sindrom anemic • Sindrom digestiv • Sindrom neurologic (in deficit de cobalamina)

  17. ANEMII MEGALOBLASTICE: diagnostic laborator • Dg. de anemie megaloblastica • Dg. etiologic

  18. ANEMII MEGALOBLASTICE: diagnostic laborator • Dg. de anemie megaloblastica HEMOGRAMA: - anemie, uneori pancitopenie - macro- ovalocitoza oxifila - pokilocitoza - indice de productie scazut - hipersegmentare granulocitara - VEM > 100 fl; MEDULOGRAMA

  19. Anemia megaloblastica – frotiu sange periferic

  20. Anemie megaloblastica: frotiu de sange periferic

  21. Anemie megaloblastica: frotiu de sange periferic

  22. ANEMII MEGALOBLASTICE: diagnostic laborator • Dg. de anemie megaloblastica MEDULOGRAMA: - hiperplazie eritroida tip megaloblastic = “maduva albastra” - metamielocite gigante - megacariocite hiperlobulate

  23. ANEMII MEGALOBLASTICE: diagnostic laborator Promegaloblastul (20-30μ) – nucleu voluminos putin excentric, cromatina fin perlata, nucleoli mari - citoplasma intens bazofila cu zona perinucleara clara Megaloblast bazofil : - nucleu mai mic, fara nucleoli, cromatina mai densa ( dar nu gramezi) Megaloblastul policromatofil -nucleu inca mare, cromatina incepe sa formeze blocuri - citoplasma bogata, policromatofila Megaloblast oxifil (10-18μ) - nucleu cu structura cromatiniana inca perceptibila - citoplasma oxifila Seria granulocitara - metamielocite gigante, hipersegmentare granulocitara Seria megacariocitara - talie mare, hiperlobulate

  24. Anemie megaloblastica: maduva

  25. ANEMII MEGALOBLASTICE: diagnostic laborator Biochimie: - creste BI / LDH / urobilinogen - sideremia crescuta

  26. ANEMII MEGALOBLASTICE: diagnostic laborator • Dg. etiologic: 1. Deficit de cobalamina: - cobalaminemia sub 100 ng / L - creste eliminarea urinara de acid metilmalonic - creste nivelul seric de homocisteina / acid metilmalonic - testul Schilling - EDS - investigatii imunologice

  27. ANEMII MEGALOBLASTICE: diagnostic laborator • Dg. etiologic: 2. Deficit de folat: - scaderea folatului seric sub 5 µg / L - scaderea folatului eritrocitar sub 160 µg / L (eritrocite)

  28. ANEMII MEGALOBLASTICE: diagnostic • Dg etiologic => proba terapeutica • Probleme de diagnostic: - anemii pluricarentiale - anemii megaloblastice incomplet tratate

  29. ANEMII MEGALOBLASTICE: Terapie 1. Deficit de cobalamina: - terapia etiologica - terapia de substitutie: 100 – 1000 µg / zi im – 2 saptamani 100 – 1000 µg / sapt. im 100 – 1000 µg / luna im – toata viata ATENTIE: - dinamica raspunsului - consumul de fier - urmarirea pe termen lung

  30. ANEMII MEGALOBLASTICE: Terapie 1. Deficit de folat: - terapia etiologica - terapia de substitutie: doza = 1-5 mg / zi ATENTIE: - dinamica raspunsului - dozele terapeutice de acid folic corecteaza anemia prin deficit de cobalamina

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