Updated: 6/18/2018

Pure Red Cell Aplasia

Topic
Review Topic
0
0
Questions
1
0
0
Snapshot
  • An 11-month-old Caucasian boy presents to the emergency department for severe fatigue. His symptoms progressively worsened to the point where he is unresponsive. On physical exam, the patient has a flat nasal bridge and triphalangeal thumbs. Laboratory testing is significant for an isolated macrocytic anemia, reticulocytopenia, and increased HbF. Genetic testing is pursued, which demonstrates a ribosomopathy.
Introduction
  • Clinical definition
    • isolated anemia and reticulocytopenia due to a pure red cell aplasia (PRCA)
  • Etiology
    • may be due to congenital (e.g., Diamond-Blackfan anemia) or acquired (e.g., transient erythroblastopenia, paraneoplastic syndromes, and parvovirus B19 infection) causes
 
Pure Red Cell Aplasia
Cause
Clinical Findings
Laboratory Findings Treatment
Diamond-Blackfan anemia (DBA)
  • Typically occurs in infancy
  • Congenital abnormalities
    • growth retardation
    • craniofacial abnormalities
      • e.g., hypertelorism and a flat nasal bridge
    • thumb abnormalities
      • e.g., triphalangeal thumbs
  • Predisposition to cancer
    • acute myelogenous leukemia
    • myelodysplastic syndrome
  • Etiology
    • congenital impairments affecting ribosome synthesis
  • Macrocytic, normochromic, and non-megaloblastic anemia
  • Reticulocytopenia
  • Increased HbF
  • Corticosteroids and blood transfusions
  • Hematopoietic cell transplantation in patients unresponsive to steroids
Transient erythroblastopenia of childhood (TEC)
  • Transient/temporary red cell aplasia
    • DBA is chronic
  • The child is otherwise healthy
  • Etiology
    • unknown
  • Normocytic anemia at the time of diagnosis
  • Reticulocytopenia
  • Patients typically recover 1-2 months without treatment
    • RBC transfusions may be needed for disabling symptoms
Parvovirus B19 
  • Patients with an underlying hemolytic process may experience an aplastic crisis with parvovirus B19 infection
    • e.g., sickle cell anemia, hereditary spherocytosis, and pyruvate kinase deficiency
  • Etiology
    • temporary cessation of RBC production with a viral infection of erythroid progenitors via a P-antigen receptor
  • Proerythroblasts and absent erythroid precursors may be seen in the bone marrow
  • Otherwise healthy children do not require treatment
  • Patients with an underlying hemolytic process receive RBC transfusions for symptomatic anemia
Paraneoplastic syndrome
  • Hemoglobin decline in a patient who has not had a transfusion and previously responded to erythropoietin
  • Etiology
    • underlying malignancy can result in the production of anti-erythropoietin antibodies
      • malignancies
        • thymoma
        • myelodysplastic syndromes
  • Bone marrow aspirate
    • severe erythroid hypoplasia
    • very little RBC precursors
  • Present anti-erythropoietin antibodies
  • Transfusions for symptomatic anemia
  • Discontinue recombinant erythropoietin (EPO) products
  • Immunosuppression
?
 

Please rate topic.

Average 5.0 of 5 Ratings

Thank you for rating! Please vote below and help us build the most advanced adaptive learning platform in medicine

The complexity of this topic is appropriate for?
How important is this topic for board examinations?
How important is this topic for clinical practice?
Questions (1)
Lab Values
Blood, Plasma, Serum Reference Range
ALT 8-20 U/L
Amylase, serum 25-125 U/L
AST 8-20 U/L
Bilirubin, serum (adult) Total // Direct 0.1-1.0 mg/dL // 0.0-0.3 mg/dL
Calcium, serum (Ca2+) 8.4-10.2 mg/dL
Cholesterol, serum Rec: < 200 mg/dL
Cortisol, serum 0800 h: 5-23 μg/dL //1600 h:
3-15 μg/dL
2000 h: ≤ 50% of 0800 h
Creatine kinase, serum Male: 25-90 U/L
Female: 10-70 U/L
Creatinine, serum 0.6-1.2 mg/dL
Electrolytes, serum  
Sodium (Na+) 136-145 mEq/L
Chloride (Cl-) 95-105 mEq/L
Potassium (K+) 3.5-5.0 mEq/L
Bicarbonate (HCO3-) 22-28 mEq/L
Magnesium (Mg2+) 1.5-2.0 mEq/L
Estriol, total, serum (in pregnancy)  
24-28 wks // 32-36 wks 30-170 ng/mL // 60-280 ng/mL
28-32 wk // 36-40 wks 40-220 ng/mL // 80-350 ng/mL
Ferritin, serum Male: 15-200 ng/mL
Female: 12-150 ng/mL
Follicle-stimulating hormone, serum/plasma Male: 4-25 mIU/mL
Female: premenopause: 4-30 mIU/mL
midcycle peak: 10-90 mIU/mL
postmenopause: 40-250
pH 7.35-7.45
PCO2 33-45 mmHg
PO2 75-105 mmHg
Glucose, serum Fasting: 70-110 mg/dL
2-h postprandial:<120 mg/dL
Growth hormone - arginine stimulation Fasting: <5 ng/mL
Provocative stimuli: > 7ng/mL
Immunoglobulins, serum  
IgA 76-390 mg/dL
IgE 0-380 IU/mL
IgG 650-1500 mg/dL
IgM 40-345 mg/dL
Iron 50-170 μg/dL
Lactate dehydrogenase, serum 45-90 U/L
Luteinizing hormone, serum/plasma Male: 6-23 mIU/mL
Female: follicular phase: 5-30 mIU/mL
midcycle: 75-150 mIU/mL
postmenopause 30-200 mIU/mL
Osmolality, serum 275-295 mOsmol/kd H2O
Parathyroid hormone, serume, N-terminal 230-630 pg/mL
Phosphatase (alkaline), serum (p-NPP at 30° C) 20-70 U/L
Phosphorus (inorganic), serum 3.0-4.5 mg/dL
Prolactin, serum (hPRL) < 20 ng/mL
Proteins, serum  
Total (recumbent) 6.0-7.8 g/dL
Albumin 3.5-5.5 g/dL
Globulin 2.3-3.5 g/dL
Thyroid-stimulating hormone, serum or plasma .5-5.0 μU/mL
Thyroidal iodine (123I) uptake 8%-30% of administered dose/24h
Thyroxine (T4), serum 5-12 μg/dL
Triglycerides, serum 35-160 mg/dL
Triiodothyronine (T3), serum (RIA) 115-190 ng/dL
Triiodothyronine (T3) resin uptake 25%-35%
Urea nitrogen, serum 7-18 mg/dL
Uric acid, serum 3.0-8.2 mg/dL
Hematologic Reference Range
Bleeding time 2-7 minutes
Erythrocyte count Male: 4.3-5.9 million/mm3
Female: 3.5-5.5 million mm3
Erythrocyte sedimentation rate (Westergren) Male: 0-15 mm/h
Female: 0-20 mm/h
Hematocrit Male: 41%-53%
Female: 36%-46%
Hemoglobin A1c ≤ 6 %
Hemoglobin, blood Male: 13.5-17.5 g/dL
Female: 12.0-16.0 g/dL
Hemoglobin, plasma 1-4 mg/dL
Leukocyte count and differential  
Leukocyte count 4,500-11,000/mm3
Segmented neutrophils 54%-62%
Bands 3%-5%
Eosinophils 1%-3%
Basophils 0%-0.75%
Lymphocytes 25%-33%
Monocytes 3%-7%
Mean corpuscular hemoglobin 25.4-34.6 pg/cell
Mean corpuscular hemoglobin concentration 31%-36% Hb/cell
Mean corpuscular volume 80-100 μm3
Partial thromboplastin time (activated) 25-40 seconds
Platelet count 150,000-400,000/mm3
Prothrombin time 11-15 seconds
Reticulocyte count 0.5%-1.5% of red cells
Thrombin time < 2 seconds deviation from control
Volume  
Plasma Male: 25-43 mL/kg
Female: 28-45 mL/kg
Red cell Male: 20-36 mL/kg
Female: 19-31 mL/kg
Cerebrospinal Fluid Reference Range
Cell count 0-5/mm3
Chloride 118-132 mEq/L
Gamma globulin 3%-12% total proteins
Glucose 40-70 mg/dL
Pressure 70-180 mm H2O
Proteins, total < 40 mg/dL
Sweat Reference Range
Chloride 0-35 mmol/L
Urine  
Calcium 100-300 mg/24 h
Chloride Varies with intake
Creatinine clearance Male: 97-137 mL/min
Female: 88-128 mL/min
Estriol, total (in pregnancy)  
30 wks 6-18 mg/24 h
35 wks 9-28 mg/24 h
40 wks 13-42 mg/24 h
17-Hydroxycorticosteroids Male: 3.0-10.0 mg/24 h
Female: 2.0-8.0 mg/24 h
17-Ketosteroids, total Male: 8-20 mg/24 h
Female: 6-15 mg/24 h
Osmolality 50-1400 mOsmol/kg H2O
Oxalate 8-40 μg/mL
Potassium Varies with diet
Proteins, total < 150 mg/24 h
Sodium Varies with diet
Uric acid Varies with diet
Body Mass Index (BMI) Adult: 19-25 kg/m2
Calculator

(M1.HE.4754) A 35-year-old male presents to his primary care physician complaining of a one-month history of progressively worsening fatigue. He sought medical attention because this has affected his ability to complete his work as a graduate student. As a child, he was hospitalized for hemolytic uremic syndrome. His past medical history is also notable for diabetes mellitus and obesity. He takes metformin and glyburide. He does not smoke and drinks alcohol occasionally. His family history is notable for chronic lymphocytic leukemia in his paternal uncle and stroke in his father. His temperature is 99.9°F (37.7°C), blood pressure is 100/70 mmHg, pulse is 110/min, and respirations are 18/min. Physical examination reveals diffuse pallor. Hematologic labs are shown below:

Hemoglobin: 8.9 g/dL
Hematocrit: 24%
Leukocyte count: 7,500 cells/mm^3 with normal differential
Platelet count: 180,000/mm^3
Mean corpuscular volume: 85 µm^3
Reticulocyte count: 0.4%

Head and neck imaging is negative for neck masses. The pathogen associated with this patient’s condition is also known to cause which of the following? Review Topic

QID: 108939
1

Kaposi’s sarcoma

10%

(22/226)

2

Erythema infectiosum

30%

(67/226)

3

Mononucleosis

35%

(80/226)

4

Croup

4%

(8/226)

5

Myocarditis

17%

(38/226)

M1

Select Answer to see Preferred Response

PREFERRED RESPONSE 2
ARTICLES (2)
Topic COMMENTS (10)
Private Note