Do individuals with hyposplenism (reduced splenic function) experience leukocytosis (high white blood cell count) in response to infection?

From the Guidelines

Yes, individuals with hyposplenism typically experience leukocytosis in response to infection, particularly with encapsulated bacteria such as Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis. This is because the spleen plays a crucial role in filtering the blood and removing pathogens, and its reduced function in hyposplenism leads to a compromised immune response. As a result, the body may respond to infection with a more pronounced leukocytosis, or elevated white blood cell count, in an attempt to compensate for the lack of splenic function 1.

Key Points to Consider

• Hyposplenism increases the risk of overwhelming post-splenectomy infection (OPSI), which can be caused by encapsulated bacteria and has a high mortality rate 1
• Vaccination against encapsulated bacteria, such as Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis, is recommended for individuals with hyposplenism to reduce the risk of OPSI 1
• Antibiotic prophylaxis may be necessary in certain situations, such as in patients with a high risk of infection or in areas where medical review is not readily accessible 1
• Clinicians should be aware of the potential for leukocytosis in hyposplenism patients with suspected infections and take this into account when making diagnostic and treatment decisions 1

Recommendations for Management

• Vaccinate individuals with hyposplenism against encapsulated bacteria, such as Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis, to reduce the risk of OPSI 1
• Consider antibiotic prophylaxis in certain situations, such as in patients with a high risk of infection or in areas where medical review is not readily accessible 1
• Educate patients with hyposplenism about the risks of infection and the importance of seeking medical attention promptly if symptoms occur 1

From the Research

Hyposplenism and Leukocytosis

• Individuals with hyposplenism (reduced splenic function) are at a higher risk of developing severe infections, particularly those caused by encapsulated bacteria such as Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis 2, 3, 4, 5.
• The spleen plays a crucial role in filtering the blood and removing pathogens, and its dysfunction can lead to an increased risk of infection 6.
• While the studies do not directly address the question of whether individuals with hyposplenism experience leukocytosis (high white blood cell count) in response to infection, they do suggest that these individuals are more susceptible to severe infections and may require prompt and aggressive treatment 2, 3, 4, 5.
• The presence of hyposplenism can be indicated by typical changes observed on the peripheral blood smear, including Howell-Jolly bodies, monocytosis, and lymphocytosis 2.
• Management of patients with hyposplenism includes a combination of immunization, antibiotic prophylaxis, and patient education to reduce the risk of infection 3, 4, 5.

Infection Risk and Management

• Patients with hyposplenism are at a higher risk of developing overwhelming post-splenectomy infection (OPSI), which can be life-threatening 5.
• The risk of OPSI can be reduced by surgical conservation of the spleen, immunization against encapsulated bacteria, prophylactic antibiotics, and patient education 5.
• Asplenic patients living in malaria-endemic areas require optimal prophylaxis to reduce the risk of infection 5.
• The creation of an asplenia register can help ensure that patients with hyposplenism receive appropriate preventive measures and treatment 5.

Sickle Cell Disease and Hyposplenism

• Sickle cell disease is a common cause of hyposplenism, with evidence of splenic dysfunction present in the majority of children with the disease before 12 months of age 6.
• Repeated splenic vaso-occlusion leads to fibrosis and progressive atrophy of the spleen, resulting in autosplenectomy (functional asplenia) 6.
• Hyposplenism in sickle cell disease increases the susceptibility to infection with encapsulated bacteria, which can be reduced by penicillin prophylaxis and immunization 6.