Aplastic anaemia

Aplastic anaemia

Aplastic anaemia:

     Results from colonyforming progeniters of mature granulocytes, megakaryocytes, erythroid cells and true stem cells.
     Haemopoetic failure is mediated by activated cytotoxic T cells in bood and marrow by producing gamma interferon and tumour necrosis factor.
     Differenciation of haemopoetic cells is regulated by humoral factors. Disturbances in these pathways lead to aplasia in



marrow cells.

*Constitutional aplastic anaemia*
(a) diamond black fan (congenital pure red cell anaemia) anaemia.
       It is macrocytic normochromic anaemia developing in early infuncy with reticulocytopenia, decreased leucocyte count. May be autosomal recessive or dominant
     C/F:
      1) facies r charactoristic with wide set eyes, thick upper lip and intelligent expression.
      2) eye anomalies like hypertelorism, blue eye, glaucoma, catract, epicanthal folds
      3) upperlimb and renal abnormalities and hypogonadism
      4)0fetal haemoglobine is elevated. Bonemarrow with decresed imature precurssors
    Rx:
      1) blood transfusion is essential
      2) prednisolon 2 mg/kg/day is mainstay
      3) spleenectomy in hyerspleenism
      4) androgens and immunosuppresive drugs
      5) bonemarrow transplantation

(b) fanconi's anaemia:
      Autosomal recessive. Aplastic anaemia is present with other stigmata like brownish pigmentation of skin (caffe'au lait spot) hypogonadism, microcephaly, short stature. Absence of thumb. Anomalies of urinary tract and squint
  Rx
  1) androgen therapy
  2) nandrolone decanoate is prefered
  3) bonemarrow transplant

(c) others
    -thrombocytopenia with absent radii and dyskeratosis conginta are rare

*acquired aplastic anaemia*
     It is common,
Aetiology:
-ideopathic
-exposure to ionising radiation, infection with parvovirus, hepatitis B,C,D virus, and epstein barr virus,
-drugs like chloranphenicol, analgin, sulfonamides, phenytoin
-Hypoplasia of marrow is due to defect in stem cells or immune mediated injury
C/F:
   Presents with progressive and persistant anaemia with insidious onset, progressive weakness and easy fatigability
   Petechiae and ecchymosis
   Mucosal bleeding, haematuria
   Prevalance of infections r common like respiratory and git.
   Lifethreatning bleeding episodes may b present.
   Headache, irritability, drowsiness suggest intracranial bleed

Lab investigations:
-pancytopenia, low reticulocute count
- increased sr iron, decreased iron binding capacity
- bone marrow aspiration is dry
- bone boipsy is hypocellular
- sugar water and ham test to r/o paroxisimal nocturnal haemoglobinuria

Severity: it is svr if,
granulocyte count is less than 500/cmm
Platelet count less than 20,000/cmm
Reticulocyye count less than 1%
Extream neutropenia less than 200/cmm carries worst prognosis

Rx:
  A) supporive care
  - platelet support to prevent bleeding
  - maintain pletlet above 20000/cmm
  - control of infections
  - red cell transfusion

  B) definative therapy
   1) bone marrow transplantation is Rx of choice
   2) immune therapy
        - antilyphocyte globuline, antithymocyte globuline and cyclosporine
        - methylprednisonol or androgens
        - various haematopoetic growrh factors such as G-CSF, recombinant human interlukins-3, and recombinant human erythropoetin
                                -by mak and ulhas-