Post-transfusion cytomegaloviremia and persistence of cytomegalovirus in blood

Neonatal cytomegalovirus infections due to blood

Infants with very low birthweights (less than 1250g) are immunocompromised and have immature hematopoietic systems. They require frequent blood transfusions and have an increased susceptibility to infection. These very low birthweight infants who lack passively acquired antibody against CMV, acquire transfusion-associated CMV infections with a frequency of approximately 30%. These infections are associated with significant morbidity and mortality. The source of these postnatally acquired CMV infections are seropositive blood donors. These infections can be prevented by appropriate donor selection and/or blood processing. Recent but limited data suggests that all infants (regardless of birthweight or the presence of antibody against CMV) should receive CMV seronegative blood products if they are likely to receive multiple transfusions from multiple donors.

Detection of human cytomegalovirus in peripheral blood lymphocytes in a natural infection

In situ hybridization was used to detect human cytomegalovirus (HCMV) in the peripheral blood mononuclear cells of some naturally infected (seropositive) individuals. A subpopulation of cells hybridized specifically to a portion of the HCMV genome that is heavily transcribed during the immediate-early period of infection. The hybridization signal was markedly reduced by base hydrolysis and ribonuclease, and therefore the probe appears to be detecting viral RNA. A fluorescence-activated cell sorter was used to select lymphocytes bearing the OKT4 and OKT8 markers. Hybridization with the HCMV probe revealed a higher proportion of positive cells in the OKT4 than in the OKT8 subset. This observation specifically identifies lymphocytes as a cell population involved in natural HCMV infection and suggests that lymphocytes may be a reservoir for maintaining infection and may also serve as a vehicle for its spread by blood transfusion.

Immunity to human cytomegalovirus measured and compared by complement fixation, indirect fluorescent-antibody, indirect hemagglutination, and enzyme-linked immunosorbent assays

The complement fixation test is currently the test employed most frequently to determine the presence of antibody to human cytomegalovirus. Several other techniques have been adapted for this purpose. A comparison of cytomegalovirus antibody titers was made between the complement fixation test, a commercially available enzyme-linked immunosorbent assay, an indirect immunofluorescent technique, and a modified indirect hemagglutination test. Forty-three serum samples were tested for antibodies by each of the above procedures. The enzyme-linked immunosorbent, immunofluorescent, and indirect hemagglutination assays were in close agreement on all samples tested; the titers obtained with these methods were all equal to or greater than the complement fixation titer for 38 of the 41 samples (92.6%). Two samples were anticomplementary in the complement fixation test but gave readable results in the other tests. The complement fixation test was the least sensitive of the procedures examined. The commercial enzyme-linked immunosorbent assay system was the most practical method and offered the highest degree of sensitivity in detecting antibodies to cytomegalovirus.

Autologous cryopreserved platelets and prophylaxis of bleeding in autologous bone marrow transplantation

Autologous platelets were harvested and cryopreserved in eight consecutive patients elected for ablative chemotherapy and autologous bone marrow transplantation (ABMT) for solid malignancy. There was a 19% loss in platelet count after the freeze thaw and wash procedure; with an in vitro functional loss of 40-60%. No correlation could be found for individual platelet transfusions between in vitro functional tests and in vivo recovery. Six consecutive patients received a total of 16 autologous platelet transfusions in the aplastic phase of ABMT. No bleeding was observed during the study period and there was no CMV infection in the recipients. While improvement in freezing and subsequent handling is desirable, autologous cryopreserved platelets can safely be used for the prophylaxis of bleeding during aplasia in patients treated with ABMT.

IgM detection by ELISA in the diagnosis of cytomegalovirus infections in homosexual and heterosexual immunosuppressed patients

A new commercially developed cytomegalovirus (CMV)-IgM ELISA was found to be sensitive and specific when compared with sucrose gradient fractionation of Ig classes in CMV antibody-positive and negative sera. The presence of CMV IgM in patients' sera correlated with positive virus isolation from circulating mononuclear blood cells and urine. Serial examinations of patients with primary or recent CMV infection revealed a typical sequence of IgM and IgG development. The frequency of CMV isolation declined as the concentration of IgM decreased and the IgG levels increased. Since the isolation of CMV from clinical specimens is a cumbersome procedure, we suggest that the IgM ELISA could provide rapid and valuable information on the presence of an active or reactivated CMV infection.

New transfusion program for an intensive care nursery

We have established a new transfusion program for an intensive care nursery which is based on crossmatching several infants to the same unit of type O Rh0(D) negative packed red blood cells, dividing the unit into quadpacks, and allowing multiple entry into each quadpack over a 24-hour period in the nursery. With this procedure, each donor unit can be used to provide multiple transfusions to four infants over a four-day period. Follow-up of transfusion recipients revealed that 20% had evidence of previous or ongoing CMB infection at 10 months of age, a prevalence comparable to that for transfused infants in other studies. We found no evidence for transmission of HB infection and a low risk of allosensitization to red cell and lymphocyte antigens.

Susceptibility of lymphoblastoid cells to infection with human cytomegalovirus

Human lymphoblastoid cells of B- and T-cell origin were examined for their in vitro susceptibility to infection with human cytomegalovirus (CMV). Results of infectious-center assays, at virus to cell ratios of 10, indicated that in each of the lymphoblastoid cell lines tested less than 1% of the cells produced infectious virus. Under these conditions, CMV specific antigens were undetectable. Infection of lymphoblastoid cells with CMV resulted in atypical virus growth curves similar to those obtained with persistently infected human embryonic kidney cells. Although some variation existed in the relative sensitivity of lymphoblasts, cells of B (Raji, P3J-HR-1, RPMI 8226) and T (CCRF-CEM) origin were susceptible to infection with CMV. Variation in the sensitivity of lymphoblasts to CMV infection did not correlate with differences in virus adsorption or the presence of Epstein-Barr virus deoxyribonucleic acid. These studies suggest that human lymphoblastoid cells could serve as a model to examine persistent CMV infection in lymphoid cells of various origin.

Transfusion-associated cytomegalovirus mononucleosis

Transfusion-associated cytomegalovirus mononucleosis is generally considered only as a complication of extracorporeal circulation following cardiac surgery. Three cases following trauma were recognized in less than one year. Both massive and limited volume blood transfusions were involved. Hectic fever was a characteristic feature in these otherwise remarkably asymptomatic individuals, without the classic features of heterophile-positive infectious mononucleosis. Since the illness developed several weeks into the post-operative period after extensive thoracic or abdominal trauma surgery, the presence of an undrained abscess was naturally the major diagnostic concern. Atypical lymphocytosis, markers of altered immunity (cold agglutinins, rheumatoid factor) and moderate hepatic dysfunction were important laboratory clues. In one case, focal isotope defects in the spleen scan misleadingly suggested a septic complication. A false-positive monospot test initially obscured the correct serologic diagnosis in the same patient. Failure to consider this selflimited viral infection may be a critical factor leading to unnecessary surgery. Other viral agents capable of eliciting a similar syndrome are cited.

Persistence of cytomegalovirus in human lymphoblasts and peripheral leukocyte cultures

The in vitro susceptibility of human peripheral lymhpocytes and lymphoblastoid (F265) cells to infection by human cytomegalovirus was examined. Infection of these cell types with cytomegalovirus resulted in a persistent type of infection rather than the typical growth curve observed with permissive fibroblastic cells. When infection of peripheral lymphocytes was associated with a blastogenic response, the virus persisted for a longer time and at a higher titer than in cells in which a blastogenic response did not occur. Autoradiographic studies and infectious-center assays indicated that only a small number of cells, resembling lymphocytes, were involved in virus persistence. Whether or not the persistence of the virus indicates release of input virus or synthesis or new virus was not determined.

Effect of storage on recovery of cytomegalovirus from necropsy tissue

Cytomegalovirus (CMV) was isolated from lung tissue in 8 of 55 (14-6%) necropsies on patients who had received immunosuppressive therapy. Recovery of CMV was best (14 of 16 specimens, 87%) from fresh tissue that had been processed immediately. Storage of specimens at 4 degrees C before inoculation into cell cultures slightly reduced, to 58%, the recovery of CMV. However, conventional freezing of tissue to -- 20 degrees C for four to seven days significantly reduced the recovery of CMV, to 25% (p less than 0-001). In three of eight specimens from which virus was recovered, CMV inclusion bodies were found on tracheal smears. Sixty-five percent of the virus-negative group had measurable complement-fixing antibody in blood taken at necropsy, compared with 86% in the virus-positive group. However, there was no significant differences in antibody levels in the two groups. Our study indicates that specimens submitted for CMV isolation should be sent for virus isolation as rapidly as possible and should not be frozen. The level of antibody in a single serum taken in necropsy does not correlate well with morphological or cultural evidence of active infection.

Evaluation of a walking-donor blood transfusion program in an intensive care nursery

A prospective study was carried out to identify the immediate and long-range advantages and disadvantages of a walking-donor transfusion program for an intensive care newborn nursery. The effect of heparin on coagulation of blood was evaluated and found to be minimal. There was no evidence of transmission of HBSAg. The prevalence of CMV infection at the time of follow-up was higher in infants who had received blood from donors seropositive for CMV than in infants who had been transfused from seronegative donors. In our experience, a walking-donor program has been a safe and effective method for the provision of small transfusions of blood to sick neonates.

Transmission of cytomegalovirus infection with renal allograft

Fifty-four patients who received a renal allograft between October 1971 and October 1974 were followed prospectively to correlate pretransplant serum antibody to cytomegalovirus (CMV) with shedding of CMV following transplantation. Twenty-five of 54 patients had antibody demonstrable to CMV using immunofluorescent techniques, but only 20 of 54 using complement-fixing techniques. All 24 who had antibody and survived one month or longer, and seven of nine without antibody but who received a kidney from a seropositive donor shed virus after transplantation, whereas none of 12 individuals without antibody and who received a kidney from a seronegative donor (P less than 0.005) shed virus. Three of eight other seronegative patients for whom donor sera were not available for analysis shed virus. Viremia occurred in eight of ten individuals who developed new antibody after transplantation, versus seven of 24 with antibody prior to transplant (P less than 0.02), and virus shedding in seroconverters from other sites was significantly more persistent than in pretransplant antibody-positive patients. Thus, CMV infection was due either to reactivation of latent infection or was transmitted along with the renal allograft and manifested as a primary infection.

Candidate cytomegalovirus strain for human vaccination

A strain of human cytomegalovirus called Towne was isolated in WI-38 human fibrolast cell cultures from the urine of an infected infant. It was then passaged 125 times in WI-38, including three clonings, and a pool was prepared in the same cell substrate for use as a potential live attenuated vaccine. The Towne virus has a broad antigenicity and cross-reacts with the AD-169 strain. Several markers of the Towne virus were found which differentiated it from fresh isolates. One of these was resistance of the former to trypsin. The Towne virus was tested for freedom from oncogenicity or other harmful effects in preparation for tests in humans.

Cytomegaloviremia in children with acute lymphocytic leukemia

Leukocyte and urine cultures were done at monthly intervals in 36 children with acute lymphocytic leukemia known to be excreting cytomegalovirus in their or saliva in order to determine the relationship of viremia to clinical cytomegalic inclusion disease. Eleven of 36 (30.5%) patients had viremia. Viremia was related to clinical disease in only three patients; two with chorioretinitis and one with a CMV monomucleosis syndrom. However, the presence of viremia did not serve as a useful means to determine active CID. Viremic patients with CID all had elevated serum levels of IgM and multiple episodes of viremia. Viremia was not related to the duration, type or number of drugs used in immunosuppression, nor to the hematologic status of leukemia. Viremic patients received more blood transfusions than noviremic patients, but the administration of blood products could not be related to the acquisition of infection. Leukopenia, neutropenia, total lymphocyte count, fourfold rise or fall in complement-fixing titer, and viruria had no consistent relationship to viremia or clinical CID.