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Updated: Jun 19, 2026

Pneumococcus Infection of Primary Human Endothelial Cells in Constant Flow

Pneumococcus Infection of Primary Human Endothelial Cells in Constant Flow

Published on: October 31, 2019

THE BLOOD PLATELETS IN PNEUMOCOCCUS INFECTIONS.

¹Hospital of The Rockefeller Institute for Medical Research.

The Journal of Experimental Medicine

|October 30, 2009

Summary

Pneumonia infection causes a drop in blood platelet counts, with numbers returning to normal weeks after fever subsides. Subsequent fevers can cause platelet counts to drop again.

Area of Science:

Hematology
Infectious Diseases
Pulmonary Medicine

Background:

Pneumonia is a significant respiratory infection.
Understanding the hematological changes during pneumonia is crucial for patient management.

Purpose of the Study:

To investigate the behavior of blood platelets during pneumonia in humans and experimentally infected rabbits.
To correlate platelet count variations with different stages of pneumonia and its sequelae.

Main Methods:

Observational study of human pneumonia patients.
Experimental infection of rabbits with pneumococci.
Monitoring of blood platelet counts throughout the disease course, including febrile, crisis, postfebrile, and sequelae periods.

Main Results:

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A decrease in platelet count (thrombopenia) was observed during the established infection and febrile period.
Platelet counts increased significantly above normal after the crisis or lysis, returning to baseline after approximately two weeks.
Recurrent fevers associated with pneumonia sequelae led to renewed platelet count diminution.
Platelets appeared smaller and more granular during the thrombopenic phase.
Antipneumococcus serum administration did not typically alter platelet counts.

Conclusions:

Blood platelet dynamics are significantly altered during pneumonia, reflecting disease activity and resolution.
Platelet count serves as a potential indicator of pneumonia progression and recovery.
Further research into the role of platelets in pneumonia pathogenesis and immune response is warranted.