Question 3.2

A patient returns for review 8 weeks following severe gunshot injuries to the chest and abdomen. His blood film is reported as showing Howell Jolly bodies.
a) What is the significance of this finding?
b) What other changes associated with this problem may be noted on blood film?
c) What specific infections is this patient at risk from (requiring vaccination)?
d) If the blood film for this patient also reported basophilic stippling of the red cells, what might be the cause?
(25% marks)

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College answer

Not available.

Discussion

This is a lot of esoteric knowledge for a question that asks four things for 25% of the total mark. Each thing is therefore worth 6.25%, i.e. 0.6 marks out of a total 10. Applying the typical exam panic calculus, that means you have 36 seconds to process and compose the answer for each section. 

a) The significance of the Howel-Jolly bodies:

This finding suggests the patient has had a trauma-related splenectomy. Howell-Jolly bodies are bits of leftover DNA in the erythrocytes. Normally, the spleen would view these as defective, and they would be removed. They are typically seen in patients who have had a splenectomy, or who are functionally asplenic for some other reason.  Other associations include the following conditions:

  • Pernicious anaemia
  • Macrocytosis of any cause
  • Corticosteroid use

b) Other abnormalities associated with splenectomy:

  • Pappenheimer bodies
  • Acanthocytes
  • Target cells
  • Spherocytes
  • Stomatocytes
  • Thrombocytosis
  • Platelet anisocytosis
  • Lymphocytosis

c) "What specific infections is this patient at risk from (requiring vaccination)?" is a weird way to phrase the question, which clearly wants to ask "what vaccinations should this patient have?", but still: let's answer it the way it was asked. The specific infections (requiring vaccination) are mainly from encapsulated organisms, and include:

  • S.pneumoniae (Pneumococcal vaccination)
  • Haemophilus influenzae (H.influenzae type b conjugate vaccine)
  • N.meningitides (Meningococcal conjugate vaccine (B, C))
  • Influenza (flu immunization)

d) Basophilic stippling of the red cells is the presence of altered ribosomes in the red cell cytoplasm, which is usually associated with lead toxicity. Could this mean that this trauma patient still has bits of lead somewhere in his body? Yes, it definitely does mean that. No joke: this happens all the time in those sorts of places in the world where gun violence is prevalent. 

References

Corazza, G. R., et al. "Howell‐Jolly body counting as a measure of splenic function. A reassessment." Clinical & Laboratory Haematology 12.3 (1990): 269-275.

Bain, Barbara J. "Diagnosis from the blood smear." New England Journal of Medicine 353.5 (2005): 498-507.

Garcés, Juan Bernardo Gerstner, and Rafael Ignacio Manotas Artuz. "Lead poisoning due to bullets lodged in the human body." Colombia Médica: CM 43.3 (2012): 230.