Functional hyposplenism following allogeneic bone marrow transplantation

Area of Science:

• Hematology
• Immunology
• Transplantation Medicine

Background:

• Allogeneic bone marrow transplantation (BMT) can lead to complications affecting immune function.
• Hyposplenism, a reduced spleen function, increases susceptibility to encapsulated bacterial infections.
• Assessing splenic function post-BMT is crucial for understanding infection risks.

Purpose of the Study:

• To determine the incidence of functional hyposplenism in patients following allogeneic BMT.
• To explore the association between functional hyposplenism and graft-versus-host disease (GvHD) post-BMT.

Main Methods:

• Splenic function was evaluated by quantifying pitted red blood cells using interference phase microscopy.
• Pitted red blood cell counts exceeding 2% indicate hyposplenism, with 25-40% seen in splenectomy patients.
• The study compared 28 BMT recipients with healthy volunteers and patients with splenic atrophy.

Main Results:

• Fifteen percent (4 of 27) of BMT recipients exhibited functional hyposplenism, with pitted red blood cell counts ranging from 5.0% to 34.0%.
• One patient with active chronic GvHD showed evidence of hyposplenism.
• Only one patient displayed typical peripheral blood red cell changes associated with hyposplenism.

Conclusions:

• Extensive chronic GvHD is confirmed as a significant factor associated with hyposplenism post-BMT.
• Functional hyposplenism can occur after BMT even without chronic GvHD or typical blood film findings.
• The presence of hyposplenism post-BMT may contribute to increased susceptibility to infections by encapsulated bacteria.