Cytomegalovirus and transfusions

A correlation analysis of HHV infection and its predictive factors in an HIV-seropositive population in Yunnan, China

Human herpesviruses (HHVs) have a particularly high prevalence in certain high‐risk populations and cause increased morbidity and mortality in patients with acquired immunodeficiency syndrome (AIDS). Screening and treating subclinical HHV infections reduce human immunodeficiency virus (HIV) infection incidence, disease progression, and transmission. However, there are few studies on HHVs, HIV coinfection rates, and their related risk factors. We aimed to clarify the prevalence of all eight HHVs in peripheral blood samples collected from HIV‐positive patients, and explore the association of HHV infection in HIV‐positive patients in an HIV‐seropositive population in Yunnan. We recruited 121 HIV‐positive patients with highly active antiretroviral therapy (HAART) and 45 healthy individuals. All the eight HHVs were detected using polymerase chain reaction and their epidemiological information and clinical data were collected and statistically analyzed. A high prevalence of HHVs (89.3%) was observed in individuals with HIV infections and with herpes simplex virus (HSV)‐2 (65.3%), and HSV‐1 (59.5%) being the most common. Coinfection with more than two different HHVs was more common in patients with HIV infections receiving HAART (72.7%) than in healthy controls. Older age, being married, higher HIV‐1 plasma viral loads, and use of antiviral protease inhibitors were independently correlated with an increased frequency of HHVs, but we found no association with CD4 count, WHO HIV clinical stage, and HIV infection duration. Our findings are of great significance for the prevention of HHV opportunistic infection in patients with AIDS and their clinical treatment.

HHV co‐infection in AIDS patients deserves attention during the course of antiviral therapy. Suppressing HHV recurrences had a clinically significant effect on prolonging survival in some cohorts of HIV‐infected patients and may be an effective intervention in reducing HIV spread in China.

Seroprevalence of cytomegalovirus antibodies among blood donors and Multitransfused recipients--a study from north India

BACKGROUND AND OBJECTIVES

Primary Cytomegalovirus infection caused by transfusion is a major problem for immunocompromised CMV seronegative patients. Documentation of the status of antibodies to cytomegalovirus in the blood donor pool population is vital to the understanding of the potential likelihood of transmission through donor blood and for determining the best transfusion practices to prevent TT-CMV infection. The present study was conducted to determine the prevalence of CMV infection among blood donors and Multitransfused recipients of north Indian population.

MATERIAL AND METHODS

A prospective study was done on 2100 donors' samples and 200 patients sample for CMV antibodies using the ELISA technique.

RESULTS

Out of 2100 donors recruited, 93.8% males and 6.2% females. 98.6% were positive for anti CMV IgG antibodies and only one donor was positive for anti CMV IgM antibody. In Multitransfused patients, out of 200 patients, seroprevalence for anti CMV IgG antibodies was in 100% patients and only one patient was positive for anti CMV IgM antibody.

CONCLUSION

The study did not demonstrate statistical significant influence of age and gender on prevalence of anti CMV IgG and IgM antibodies. Other preventive strategies such as universal leucodepletion may be implemented to prevent transmission of CMV in immunocompromised patients.

Audit of practice in platelet refractoriness

OBJECTIVES

A significant number of patients become refractory to platelet transfusion and prompt investigation of the cause will encourage appropriate selection of platelet products.

METHODS

We surveyed haematologists to assess perceived practice concerning platelet refractoriness because of the high cost and limited availability of HLA-compatible platelets. Some 56 of 58 consultant haematologists participated.

RESULTS

Clinicians differed on their definition of platelet refractoriness, and non-immune factors were not considered as important as immune causes of platelet refractoriness. A working group, including an invited moderator, was established to produce guidelines on recommended practice for the management of platelet refractoriness. Re-audit after implementation of the guidelines showed that more patients receiving HLA-compatible platelets had been tested for HLA antibodies. There was a mean 50.9% reduction in the use of HLA-compatible platelets.

CONCLUSIONS

Increased testing for leucocyte and platelet antibodies resulted in reduced demand for and more selective use of HLA-compatible platelets, with no apparent increase in haemorrhagic complications.

Blood transfusion in beta thalassaemia major

Conventional treatment of beta thalassaemia major is based on regular blood transfusion from early childhood. Maximum effectiveness of transfusion therapy depends on the following. (1) Availability of safe blood. Donation programmes should aim at retaining repeat donors, who carry decreased risk of transmitting blood-borne infections. Donors should be screened with laboratory tests performed to the highest possible standard of quality. Selection of safe donors can be improved by the adoption of questionnaires containing direct questions on risk factors for transfusion transmissible infections. (2) Use of good quality red blood cells, which should be leucodepleted, preferably by filtration, that can be carried out at the bedside. (3) Regular evaluation of blood transfusion indices, including mean level of haemoglobin maintained, annual blood requirement, daily haemoglobin fall, mean transfusion interval, transfusion reaction rate. This can be assisted by the use of a computerized patient record. (4) Maintenance of a permanent record of the patient's blood group genotype (including at least Rh, Kell, Kidd and Duffy systems) and any red cell antibodies that develop. This is mandatory to ensure optimal survival of transfused red cells. (5) Continuous monitoring of transfusion transmissible infections. (6) Vaccination against hepatitis B of all suitable patients. (7) Intensive iron chelation. This should be done by regular subcutaneous administration of desferrioxamine B. Oral chelators, which are currently under laboratory and clinical evaluation, are not yet available for general use.

The diagnosis of anal ulcers in AIDS patients

Recent reports have suggested that routine microscopic evaluation of anal ulcer tissue from AIDS patients is not the most accurate way to diagnose viral infection. This study was undertaken to determine if either viral culture (VC) or immunohistochemistry (IHC) can improve the diagnostic accuracy as compared with routine hematoxylin and eosin (H&E) staining. Specifically, we sought to identify inclusion bodies of cytomegalovirus (CMV) or herpes simplex virus (HSV) to assist in the diagnosis of CMV or HSV. All patients had clinical evidence of an anal ulcer or a nonhealing anal fissure. Duration of symptoms ranged from 1 week to 3 months with a mean of 6 weeks. All specimens were submitted for viral culture in addition to routine H&E staining; immunohistochemistry was also performed. Twenty-five paraffin-embedded anal ulcer biopsies from 23 male patients (age range 27-73; mean 37.4 years) with the diagnosis of AIDS or AIDS-related complex (ARC) were reviewed over a 4 year period (1988-1992). Routine H&E staining revealed 6 (22%) specimens with CMV inclusions. Four of these 6 reacted positively with IHC (67%) and one was positive on viral culture (17%). In the remaining 19 specimens that did not reveal infection with CMV (78%), IHC was positive in 2 patients (10%) and viral culture was positive in 1 patient (5%). Although HSV was not seen in any of the specimens on H&E staining, IHC was positive in one patient (3.5%) and viral culture reacted positively in 8 (29%) specimens. Thus IHC is a good confirmatory test for CMV inclusions and can be used to achieve a definitive diagnosis in equivocal cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of the Vitek Immunodiagnostic Assay System with three immunoassay systems for detection of cytomegalovirus-specific immunoglobulin G

The Vitek Immunodiagnostic Assay System (VIDAS; bioMerieux Vitek Inc., Hazelwood, Mo.) was evaluated for its ability to detect anticytomegalovirus immunoglobulin G (IgG) and was compared with the following assay systems: Abbott IMx Cytomegalovirus IgG antibody assay (Abbott Laboratories, Abbott Park, Ill.), Whittaker Cytomegelisa II IgG assay (Whittaker Bioproducts, Walkersville, Md.), and Whittaker FIAX Cytomegalovirus IgG assay (Whittaker Bioproducts). Samples were considered positive if at least two of three (IMx, Cytomegelisa II, and FIAX) comparative assays gave positive results; a sample was considered negative if at least two of the three assays were negative. Of the 199 clinical serum samples tested, 194 gave concordant results among the three comparative assays (145 were positive and 49 were negative). The VIDAS results with two samples were persistently equivocal and were therefore excluded from the comparison study. The overall agreement between VIDAS and the established standard was 98.5%. The VIDAS assay yielded one false-positive and two false-negative results. The intra- and interassay precision studies indicate that the VIDAS assay is suitable for clinical use. The VIDAS system is rapid, self-contained, and fully automated and would be useful for screening of cytomegalovirus immune status.

Blood-borne Infections Associated with Transfusion

The epidemic of acquired immunodeficiency syndrome (AIDS) and the realization that transmission of human immunodeficiency virus is caused by homologous blood transfusion have changed the way physicians and their patients view the safety of hemotherapy. Considering that nearly four million patients receive the lifesaving benefits of blood transfusions every year in the United States, we need to recognize and reduce the inherent biological complications of this therapy. Currently, a major concern is the transmission of blood-borne infectious agents and the establishment of persistent infection in transfusion recipients, which is apparently facilitated by suppression of the recipient's hematopoietic and immune systems. Education of blood donors, patients, and attending physicians regarding infectious complications of transfusion is essential and remains the most effective procedure for making rational decisions. Before giving blood transfusions, astute physicians should calculate a risk/benefit ratio and communicate it to the patient or family. Potential recipients of transfusions can be assured that the blood supply is safer now than at any time in the past, although there is still a very small risk for the transmission of infectious agents that cause chronic diseases, such as hepatitis, AIDS, neuropathies, and leukemias. It is essential that everyone understands that the goal of a zero-risk blood supply is not attainable. Recent developments in molecular biology and biotechnology, however, provide opportunities for further reduction of infectious complications of blood transfusions.

Cytomegalovirus testing: antibody determinations and virus cultures with recommendations for use

Human cytomegalovirus is a ubiquitous virus with the property of becoming latent in the immunocompetent host. It can also cause devastating infections in the immunocompromised patient. Several different assays are available to detect either cytomegalovirus antibodies or cytomegalovirus itself, five of which are used at the University of Wisconsin Hospitals and Clinics and the Wisconsin State Laboratory of Hygiene. The latex agglutination (LA) test is used to detect antibody positivity in transplant donors, transplant recipients, and others. The complement fixation (CF) test is used to detect seroconversion or reactivation of infection in the CMV positive host. The immunofluorescent antibody-IgM (IFA-IgM) test is used to diagnose infection in congenitally or neonatally infected infants. The "routine" CMV culture is the "gold standard" for the detection of the cytomegalovirus in patient secretions. The shell vial assay, a rapid method of detecting virus, is most useful when contemplating therapy for active CMV infection. The advantages and limitations, as well as the timing and appropriateness of each test, are reviewed.

The preparation of platelet concentrates by the light-spin/hard-spin technique

For at least two decades the light-spin/hard-spin (LS/HS) method for preparation of platelet concentrates (PC) has been the standard of platelet support. With concern over the detrimental effects of platelet activation during component preparation and with increased recognition of the adverse consequences resulting from residual donor leukocytes in PC, new approaches to the production of PC have begun. This review addresses two aspects of the traditional LS/HS method of platelet preparation: platelet activation and residual leukocyte content. Studies of platelet activation are reviewed which focus on the second (hard-spin) centrifugation step during which pelleting of platelets occurs. Platelets studied immediately after the hard-spin exhibit evidence of alpha-granule release, expression of activation antigens, and decreased aggregation. There is a suggestion that some degree of reversal of platelet activation routinely occurs during the rest period following the hard-spin. The residual leukocyte content of PC prepared by the LS/HS method ranges from 10 7 to 10 9 leukocytes/unit. The residual donor leukocytes are predominantly lymphocytes and monocytes. Degeneration of residual donor leukocytes may release soluble cytokines resulting in febrile transfusion reactions. It remains controversial whether or not the cell-membrane fragments and microvesicles of degenerating donor leukocytes are capable of HLA allosensitization or viral transmission. Release of leukocyte elastase from degenerating leukocytes during platelet storage has been proposed as contributing to the platelet storage lesion. More research is needed to address the question of whether or not pre-storage leukocyte reduction during component preparation will result in improved PC. It appears likely that within the next few years radical changes will occur in the method of preparation of PC with the aim of providing the greatest degree of hemostatic effectiveness with the least toxicity to patients.