Hemovigilance and the Notify Library

Hemovigilance systems allow reporting of adverse occurrences associated with blood transfusion to a central database where events can be reviewed and analyzed for the benefit of patients and donors. Hemolytic and serologic transfusion reactions are among the many types of reactions reported to these systems. The Notify Library, a database of adverse events associated with medical products of human origin, has incorporated hemovigilance into its didactic resources. Students and practitioners are encouraged to use the electronic library and to further enhance this resource through review and recommendation of additional publications in the area of immunohematology. Hemovigilance systems allow reporting of adverse occurrences associated with blood transfusion to a central database where events can be reviewed and analyzed for the benefit of patients and donors. Hemolytic and serologic transfusion reactions are among the many types of reactions reported to these systems. The Notify Library, a database of adverse events associated with medical products of human origin, has incorporated hemovigilance into its didactic resources. Students and practitioners are encouraged to use the electronic library and to further enhance this resource through review and recommendation of additional publications in the area of immunohematology.

Congenital cytomegalovirus infection: patterns of fetal brain damage

Cytomegalovirus (CMV) is the most prevalent infectious agent causing neurological dysfunction in the developing brain. This study analysed the different patterns of tissue damage, particularly in the brain, of fetuses with documented CMV infection. We studied 45 fetuses at 20-21 weeks of gestation with congenital CMV infection documented by invasive positive prenatal diagnosis. At the time of amniocentesis, abnormal ultrasound findings had been recorded for 13 of the 45 fetuses (29%). Histological and immunohistochemical characterization was performed on the placenta, brain, heart, lung, liver, kidney, and pancreas. The different degrees of brain damage were correlated with tissue viral load, inflammatory response, placental functionality, and extramedullary haematopoiesis. Even though a high CMV load was detected in all amniotic fluids, brain infection occurred in only 62% of the fetuses and with different degrees of severity. Tissues with a low viral load showed a globally weak inflammatory response, and fetuses had only mild brain damage, whereas tissues with a high CMV load showed prominent infiltration of the activated cytotoxic CD8(+) T-lymphocytes responsible for immune-mediated damage. Furthermore, severe placental infection was associated with diffuse villitis and necrosis, consistent with functional impairment and possible consequent hypoxic cerebral damage. Brain injury induced by CMV congenital infection may be the result of uncontrolled viral replication, immune-mediated damage by cytotoxic CD8(+) T-lymphocytes, and, in the presence of placental insufficiency, fetal hypoxia.

Monitoring cytomegalovirus T-cell immunity in small bowel/multivisceral transplant recipients

BACKGROUND

Cytomegalovirus (CMV) is a major cause of graft failure and posttransplantation mortality in intestinal/multivisceral transplantation. CMV infection exhibits a wide range of clinical manifestations from asymptomatic infection to severe CMV disease. STUDY'S PURPOSE: The purposes of this study were to assess the utility of measuring CMV-specific cellular immunity in bowel/multivisceral transplant recipients and to provide additional information on the risk of infection and development of CMV disease.

METHODS

We studied 10 bowel/multivisceral transplant recipients to investigate the kinetics of CMV infection using real-time polymerase chain reaction (on blood and biopsy tissue samples) and CMV-specific T-cell reconstitution by Enzyme-linked ImmunoSPOT Assay (ELISPOT) that enumerates Interferon-gamma-secreting CMV-specific T cells upon in vitro stimulation with viral antigens (pp65 and IE-1).

RESULTS

All patients were seropositive for CMV. According to the pattern of T-cell reconstitution occurring either within the first month after transplantation or later, patients were classified as early (n = 7) or late responders (n = 3). Clinically, early responder patients (3/7; 43%) experienced asymptomatic or mild CMV infections, whereas all late responders (3/3; 100%) developed moderate or severe CMV disease. A reduction in mean and peak CMV viral load was observed in early responders, whereas the onset time of infection did not differ significantly between early and late CMV responders.

CONCLUSIONS

A good and early reconstitution of CMV-specific T-cell immune responses after transplantation is a critical determinant in controlling CMV infections. Simultaneous monitoring of CMV infection and CMV-specific T-cell immunity predicts T-cell-mediated control of CMV infection.

Early and late virological monitoring of cytomegalovirus, Epstein-Barr virus, and human herpes virus 6 infections in small bowel/multivisceral transplant recipients

BACKGROUND

Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) are the major causes of graft failure and posttransplantation mortality among small bowel and multivisceral transplantations (SB/MVT). Little is known about human herpes virus 6 (HHV-6) infections in transplant recipients.

STUDY PURPOSE

The purposes of this study were to analyze the clinical relevance of CMV, EBV, and HHV-6 infections after small bowel transplantation and to establish whether routine monitoring for HHV-6 infection should be recommended for the prevention of severe complications in this population.

METHODS

Ten adult patients were monitored based on CMV, EBV, and HHV6 DNA quantifications in blood and biopsy tissue samples. Three patients were monitored for at least 5 months (early period) and 7 patients were monitored for 1 to 5 years after transplantation (late period).

RESULTS

In the early period, despite prophylaxis all 3 patients developed symptomatic CMV infections: 1 fever/diarrhea, 1 enteritis and rejection, as well as 1 fever and pneumonia. Only 1 patient developed EBV and HHV-6 infections. The average time of onset of CMV infection was 3 months after transplantation and only 24 days for HHV6 infection. In the late period, of the 7 SB/MVT recipients only 1 developed an EBV infection at 2 years after transplantation. No CMV or HHV-6 infections were identified in any patient.

CONCLUSIONS

CMV infection is a major cause of organ disease and rejection in the early period after transplantation. EBV infection in adult recipients must be considered also in the late period, particularly in association with severe immunosuppression. Because HHV-6 infection occurs earlier than CMV/EBV, it may serve as an indicator for more intense virological surveillance.