Myelopoiesis in the infected burn

A modified bone marrow clonal cell culture technique was used to study granulocyte production during burn injury and sepsis. When rats were inflicted with a 30 percent third-degree scald burn, marrow cellularity and colony-forming units in culture (CFU-C) per 10(5) marrow cells increased progressively to four times normal by 7 days after injury. Conversely, When animals were burned and the burn wound immediately seeded with 10(8) Pseudomonas organisms, CFU-C declined steadily until the day of death and reflected a progressive loss in marrow cellularity. Further studies were conducted replacing or mixing standard colony-stimulating serum with burn, burn-infected, or normal rat serum. The results indicated that colony-stimulating activity could be supplied by postburn serum, but not with normal or burn-infected rat serum. Additionally, serum from burned-infected animals significantly inhibited colony formation when added to the standard colony-stimulating serum. Marrow failure appears to be the major cause for granulocytopenia in burn infection and may partly be serum mediated.