What is the significance of Howell-Jolly bodies in the peripheral smear of my patient with a spleen who presents with pneumonia?

Howell-Jolly bodies (HJBs, Figure) are often indicative of asplenia (either post-splenectomy or congenital absence) or hyposplenism associated with a variety of conditions, including  sickle cell disease, autoimmune disorders, celiac disease, inflammatory bowel disease (particularly ulcerative colitis), HIV, cirrhosis, primary pulmonary hypertension, splenic irradiation, amyloidosis, sarcoidosis, bone marrow transplantation, and high-dose corticosteroid therapy1-4.

Patients with pneumonia and HJBs on peripheral smear may be hyposplenic and at risk of potentially serious infections, predominantly caused by encapsulated bacteria eg, Streptococcus pneumoniae, Haemophilus influenzae and Neisseria meningitidis3.  Such patients should be immunized against these organisms, including sequential receipt of both conjugated and polysaccharide pneumococcal vaccines3,5.

HJBs are nuclear remnants in circulating mature red blood cells which are usually pitted by the spleen under normal physiological conditions. 

Final Fun Pearl:  Did you know that  HJBs were named after Henry Howell, an American physiologist who pioneered the use of heparin as an anti-coagulant and Justin Jolly, a French hematologist who was among the first to film mitotic activity in cells?

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Figure. Howell-Jolly body in an RBC. Photo courtesy of Michael S. Abers, MD

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References

  1. Di Sabatino, A, Carsetti R, Corazza G. Post-splenectomy and hyposplenic states. Lancet 2011;378:86–97. https://www.ncbi.nlm.nih.gov/pubmed/21474172
  2. Brousse, V, Buffet P, Rees D. The spleen and sickle cell disease: the sick(led) spleen. Br J Haematol 2014;166: 165–176. https://www.ncbi.nlm.nih.gov/pubmed/24862308
  3. Mathew H, Dittus C, Malek A, Negroiu A. Howell-Jolly bodies on peripheral smear leading to the diagnosis of congenital hyposplenism in a patient with septic shock. Clin Case Rep 2015;3:714-717. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4551333
  4. Ryan FP, Smart RC, Holdsworth CD, et al. Hyposplenism in inflammatory bowel disease 1978;19:50-55. https://www.ncbi.nlm.nih.gov/pubmed/624506
  5. Kuchar E, Miśkiewicz K , Karlikowska M. A review of guidance on immunization in persons with defective or deficient splenic function. Br J Haematol 2015; 171:683-94.  http://onlinelibrary.wiley.com/doi/10.1111/bjh.13660/full

Contributed by Katarzyna Orlewska, Medical Student, Warszawski Uniwersytet Medyczny, Poland

What is the significance of Howell-Jolly bodies in the peripheral smear of my patient with a spleen who presents with pneumonia?

Is there a seasonal variation in the incidence of cardiovascular (CV) events or venous thromboembolism (VTE)?

Seasonal variation, primarily characterized by a winter peak, has been reported for acute CV events, such as acute myocardial infarction (AMI) and sudden death, aortic rupture or dissection, and ischemic or hemorrhagic stroke, and VTE (1). A meta-analysis involving patients with VTE, primarily with a diagnosis of pulmonary embolism, revealed a 20% absolute increase in the incidence of VTE during January (1).  

Potential physiological mechanisms for these observations include increased sympathetic activity, decreased loss of fluids and sodium, increase in LDL cholesterol, increase in serum fibrinogen levels and other coagulation markers and C-reactive protein, and lower vitamin D levels due to shorter daylight hours during winter months (1,2).  At least in the case of AMI in the U.S., the higher incidence in winter is not affected by climate (2).  

Respiratory virus infections as a cause of acute inflammation leading to  CV or VTE events is another intriguing explanation (3). Indeed, influenza vaccination has been associated with reduction in hospitalization for cardiac disease and stroke among the elderly (4) and, in patients with cardiovascular disease, a reduction in death due to combined cardiovascular disease events such as heart attacks and strokes (5).

 

 

References

  1. Dentali F, Ageno W, Rancan E, et al. Seasonal and monthly variability in the incidence of venous thromboembolism. A systematic review and a meta-analysis of the literature. Thromb Haemost 2011;106:439-447. https://www.ncbi.nlm.nih.gov/pubmed/21725580
  2. Spencer FA, Goldberg RJ, Becker RC, et al. Seasonal distribution of acute myocardial infarction in the Second National Registry of Myocardial Infarction. J Am Coll Cardiol 1998;31:1226-33.h ttps://www.ncbi.nlm.nih.gov/pubmed/9581712
  3. Woodhouse PR, Khaw KT, Plummer M, et al. Seasonal variations of plasma fibrinogen and factor VII activity in the elderly: winter infections and death from cardiovascular disease. Lancet 1994;343:435-39.  https://www.ncbi.nlm.nih.gov/pubmed/7508540
  4. Nichol KL, Nordin J, Mulloly J, et al. Influenza vaccination and reduction in hospitalization for cardiac disease and stroke among the elderly. N Engl J Med 2003; 348:1322-1332. http://www.nejm.org/doi/full/10.1056/NEJMoa025028
  5. Clar C, Oseni Z, Flowers N, et al. Cochrane Database of Systematic Reviews 2015. DOI: 10.1002/14651858.CD005050.pub3h ttp://www.cochrane.org/CD005050/VASC_flu-vaccines-for-preventing-cardiovascular-disease  

 

 

 

 

Is there a seasonal variation in the incidence of cardiovascular (CV) events or venous thromboembolism (VTE)?