CMV (Memo Therapeutics)

Interstitial pneumonitis is one of the major causes of morbidity and mortality following bone marrow transplantation (BMT). Based on the Japanese BMT Registry, however, since 1983 the incidence of interstitial pneumonitis at one year has decreased to 32% by means of several efforts, such as fractionated low-dose rate total body irradiation, selection of platelet donor from cytomegalovirus (CMV) seronegative donor, and prophylactic administration of anti-CMV high titer globulin. Cytomegalovirus (58%) was the most frequently causative organism within 100 days after bone marrow transplantation. On the other hand, idiopathic interstitial pneumonitis (44%) was the leading cause more than 100 days after bone marrow transplantation. There was a significant difference in onset after bone marrow transplantation against leukemia between cytomegalovirus (mean: 90 +/- 15 days) and idiopathic interstitial pneumonitis (mean: 186 +/- 32 days) (p less than 0.01).

Among infections in leukemia patients during their first induction treatment pneumonia was the third most frequent infection (11.4%) following fever of unknown origin and sepsis. Granulocytopenia was suggested to be very closely related to the onset of pneumonia. Laminar air flow rooms seemed very effective for preventing exogenous infections including pneumonia. They reduced pneumonia from 30 to 0 in 106 patients with acute leukemia during their first induction treatment. Bone marrow transplantation (BMT) is one of the most intensive immunosuppressive treatments. Major causes of failure were interstitial pneumonitis (IP) due to cytomegalovirus (CMV), relapse of leukemia and bacterial and fungal infections. The incidence of IP was reduced by fractionation of total body irradiation and selection of CMV antibody negative donor for platelet transfusion. Administration of anti CMV immunoglobulin has also reduced the incidence of IP significantly from 37.5% to 11.5%. Colony stimulating factor appeared to stimulate the recovery of leukocytes after BMT. By several modifications of BMT techniques, mainly for the prevention of infection and IP, the survival of patients after BMT has improved significantly from 20% to 85%. In conclusion, prevention and treatment of respiratory infections are important in the treatment of leukemia, both for chemotherapy and BMT.