I. Indication

II. Contraindications

  1. Recent Transfusion (not diagnostic after transfusion)

III. Measures

  1. Reticulocyte Count
    1. Reticulocyte percentage of total erythrocytes
    2. Does not correct for degree of Anemia
  2. Absolute Reticulocyte Count (ARC)
    1. Number of Reticulocytes present in 1 mm3 blood
    2. ARC = (Reticulocyte %) / 100 * Erythrocyte Count
  3. Reticulocyte Index (RI)
    1. Adjusts Reticulocyte Count for Hematocrit
    2. Reticulocyte Index reflects Bone Marrow activity
      1. Known as "Poor man's Bone Marrow Aspirate"
    3. Calculation
      1. RI = Reticulocyte Count x (HCT / normal HCT)

IV. Technique

  1. Stain Solution (Stains ribosomes)
    1. New methylene blue or Azure B 1.0 grams
    2. Dissolve stain in 100 ml Citrate-Saline
      1. Tri-sodium citrate 3% (one part)
      2. Saline 0.85% (four parts)
    3. Filter solution
    4. Store at 4 degrees celsius
  2. Staining method
    1. Start with 2-3 drops of stain in tube
    2. Add 2-3 drops of patient's blood
      1. Use more blood in anemic patients
      2. Use less blood in polycythemia
    3. Incubate at 37 degrees celsius for 15-20 minutes
    4. Gently mix
    5. Create a thin film on slide
    6. Allow films to dry
  3. Counting method
    1. View field of undistorted cells at x100 oil immersion
      1. Reticulocytes stain deep blue
      2. Red Blood Cells stain pale-greenish blue
    2. Use Miller ocular insert
      1. nRBC: average Red Blood Cells in small square
      2. nRetic: Number of Reticulocytes in 'nField' fields
    3. Calculate Reticulocyte Count
      1. Calculate Reticulocytes per 1000 red cells
      2. Retic Count = (nRetic) / (9 * nRBC * nField)

V. Interpretation

  1. Normal Reticulocyte Count: 0.5-1.5%
  2. Normal Reticulocyte Index: 1-3%

VI. Reticulocytosis (Increased RBC Production)

  1. Criteria
    1. Reticulocyte Index >3%
    2. Reticulocyte Count >1.5%
  2. Conditions
    1. Acute blood loss or Hemorrhage
    2. Post-Splenectomy
    3. Acute Hemolytic Anemia (Microangiopathic Anemia)
      1. Example: Autoimmune Hemolytic Anemia
      2. Usually ARC > 100 x10^6/L and Retic Count >2%
    4. Hemoglobinopathy
      1. Sickle Cell Anemia
      2. Thalassemia major
    5. Post-Anemia Treatment
      1. Folate Supplementation
      2. Iron Supplementation
      3. Vitamin B12 Supplementation

VII. Reticulocytopenia (Decreased RBC Production)

  1. Criteria
    1. Reticulocyte Index <1%
    2. Reticulocyte Count <0.5%
  2. Conditions
    1. Aplastic Anemia
    2. Bone Marrow infiltrate
    3. Bone Marrow suppression or failure
      1. Sepsis
      2. Chemotherapy or radiotherapy
    4. Disordered RBC maturation
      1. Iron Deficiency Anemia
      2. Vitamin B12 Deficiency
      3. Folate Deficiency
      4. Sideroblastic Anemia
      5. Anemia of Chronic Disease
      6. Hypothyroidism
    5. Blood Transfusion
    6. Liver disease

VIII. Resources

  1. HTP Blood Safety and Clinical Technology
    1. http://w3.whosea.org/haem/c12.htm

Images: Related links to external sites (from Google)

Ontology: Reticulocytosis (C0206160)

Definition (MSH) An increase in circulating RETICULOCYTES, which is among the simplest and most reliable signs of accelerated ERYTHROCYTE production. Reticulocytosis occurs during active BLOOD regeneration (stimulation of red bone marrow) and in certain types of ANEMIA, particularly CONGENITAL HEMOLYTIC ANEMIA.
Concepts Finding (T033)
MSH D045262
SnomedCT 165491008, 142899000, 46049004
French RETICULOCYTOSE, Réticulocytose
English RETICULOCYTOSIS, RBC's - reticulocytes present, Reticulocyte count above reference range, Reticulocytosis [Disease/Finding], Reticulocytoses, Reticulocytosis (finding), Reticulocytosis
Portuguese RETICULOCITOSE, Reticulocitose
Spanish RETICULOCITOSIS, Reticulocytosis, recuento de reticulocitos por encima del rango de referencia, reticulocitosis (hallazgo), reticulocitosis, Reticulocitosis
Japanese 網状赤血球増加症, モウジョウセッケッキュウゾウカショウ
Swedish Retikulocytos
Czech retikulocytóza, Retikulocytóza
Finnish Retikulosytoosi
Italian Reticolocitosi
Russian RETIKULOTSITOZ, РЕТИКУЛОЦИТОЗ
German RETIKULOZYTOSE, Retikulozytose
Polish Retikulocytoza
Hungarian reticulocytosis
Dutch reticulocytose, Reticulocytose

Ontology: Reticulocytopenia (C0858867)

Concepts Finding (T033)
SnomedCT 124961001
Italian Reticolocitopenia
Japanese 網赤血球減少症, モウセッケッキュウゲンショウショウ
Czech Retikulocytopenie
Hungarian reticulocytopenia
English Reticulocytopenia, Reticulocytopenia (finding)
Spanish reticulocitopenia (hallazgo), reticulocitopenia, Reticulocitopenia
Portuguese Reticulocitopenia
Dutch reticulocytopenie
French Réticulocytopénie
German Retikulozytopenie