High prevalence of cytomegalovirus DNA in plasma samples of blood donors in connection with seroconversion

Cytomegalovirus seroprevalence among blood donors: a systematic review and meta-analysis

Background

Screening for cytomegalovirus (CMV)-specific antibodies is not routine in some settings. Thus, transfusion of blood products poses risks for susceptible individuals.

Objectives

To investigate the global pooled CMV seroprevalence among volunteer blood donors.

Methods

This systematic review and meta-analysis was performed according to PRISMA guidelines. The databases searched included Embase, Google Scholar, Medline, PubMed, Web of Science, and Cochrane Library. Data were extracted independently and analyzed using STATA version 11.

Results

The global seroprevalence of CMV IgG, CMV IgM, and both CMV IgM and IgG was 83.16% (95% confidence interval [CI]: 78.55–87.77%, I² = 99.5%), 13.77% (95% CI: 11.59–15.95%, I² = 98.8%), and 23.78% (95% CI: 10.50–37.06%, I² = 98.7), respectively.

Conclusion

The global seroprevalence of CMV was high among blood donors. Therefore, regular CMV screening should be conducted to identify CMV-seronegative blood donors.

Transfusion in Neonatal Patients: Review of Evidence-Based Guidelines

Transfusion of red blood cells, platelets, and fresh frozen plasma in neonatal patients has not been well characterized in the literature, with guidelines varying greatly between institutions. However, anemia and thrombocytopenia are highly prevalent, especially in preterm neonates. When transfusing a neonatal patient, clinicians must take into consideration physiologic differences, gestational and postnatal age, congenital disorders, and maternal factors while weighing the risks and benefits of transfusion. This review of existing literature summarizes current evidence-based neonatal transfusion guidelines and highlights areas of current ongoing research and those in need of future studies.

Transfusion-transmitted and community-acquired cytomegalovirus infection in seronegative solid organ transplant recipients receiving seronegative donor organs

Solid organ transplant (SOT) recipients who are cytomegalovirus (CMV) seronegative (R-) and receive seronegative donor (D-) organs have a small but currently unquantified risk of both transfusion-transmitted CMV (TT-CMV) and community-acquired CMV (CA-CMV). We retrospectively studied the incidence and clinical symptoms of TT-CMV (infection <1 year posttransplant) and CA-CMV (infection >1 year posttransplant) in a cohort of D-/R- adult and pediatric SOT recipients receiving leukoreduced blood products not screened for CMV seronegativity transplanted at our center between 2000 and 2011. CMV infection was defined as IgG seroconversion or detectable CMV antigenemia/DNAemia. Among 536 consecutive D-/R- recipients, 398 (81.8%) had adequate follow-up, and 231 (58%) received cellular blood products (total: 1626 red blood cell units, 470 platelet units) 30 days pretransplant to 90 days posttransplant. We observed no confirmed TT-CMV cases, but 14 CA-CMV cases (64% symptomatic) were seen. The estimated incidence rate of CA-CMV was higher in children (3.0/100 patient years) than adults (0.46/100 patient years, incident rate ratio of 6.52). The absence of TT-CMV over 11 years suggests neither seronegative blood products nor CMV DNA blood donor screening would provide significant incremental safety when blood is already leukoreduced. D-/R- SOT recipients, particularly children, have a significantly higher and ongoing risk of CA-CMV.

Transfusion-transmitted cytomegalovirus: behaviour of cell-free virus during blood component processing. A study on the safety of labile blood components in Switzerland

BACKGROUND

Nowadays, most blood products are leukocyte-reduced. After this procedure, the residual risk for transfusion transmitted cytomegalovirus (TT-CMV) is mostly attributed to cell-free viruses in the plasma of blood donors following primary infection or viral reactivation. Here, objectives are: 1) to study the behaviour of cell-free CMV through the blood component processing; 2) to determine the anti-CMV seroprevalence, the level of viremia, the window-period in blood donor population; and 3) to identify cases of TT-CMV in bone marrow transplant (BMT) recipients.

MATERIALS AND METHODS

Cell-free CMV was injected into blood bags originating from regular donors. Blood components were processed according to either the CompoSelect^® or the CompoFlow^® (Fresenius Kabi AG) techniques. Samples were analysed at each step for presence of virus DNA using quantitative polymerase chain reaction (PCR). The anti-CMV seroprevalence in our donor population was taken from our donor data system. The viremia was assessed in pooled plasmas samples from routine donations by quantitative PCR. Medical charts of 165 BMT anti-CMV seronegative recipients/anti-CMV seronegative donors who received CMV-unscreened blood products were reviewed.

RESULTS

Cell-free CMV passes without any decrease in viral load through all stages of blood processing. The anti-CMV seroprevalence was 46.13%. Four DNA positive samples out of 42,240 individual blood donations were identified (0.009%); all had low levels of viremia (range 11-255 IU/mL). No window-period donation was identified. No TT-CMV was found.

DISCUSSION

Cell-free CMV remains a concern with current blood component processing as it passes through all the processes. However, since low levels of CMV DNA were identified in the donations tested, and no BMT recipients had TT-CMV, the residual threat of TT-CMV after leukocyte reduction appears to be very low.

Transfusion of pathogen-reduced platelet components without leukoreduction

BACKGROUND

Leukoreduction (LR) of platelet concentrate (PC) has evolved as the standard to mitigate risks of alloimmunization, clinical refractoriness, acute transfusion reactions (ATRs), and cytomegalovirus infection, but does not prevent transfusion-associated graft-versus-host disease (TA-GVHD). Amotosalen-ultraviolet A pathogen reduction (A-PR) of PC reduces risk of transfusion-transmitted infection and TA-GVHD. In vitro data indicate that A-PR effectively inactivates WBCs and infectious pathogens.

STUDY DESIGN AND METHODS

A sequential cohort study evaluated A-PR without LR, gamma irradiation, and bacterial screening in hematopoietic stem cell transplant (HSCT) recipients. The first cohort received conventional PC (control) processed without LR, but with gamma irradiation and bacterial screening. The second cohort received A-PR PC (test) processed without: LR, bacterial screening, or gamma irradiation. The primary efficacy outcome was the 1-hour corrected count increment. The primary safety outcome was treatment-emergent ATR. Secondary outcomes included clinical refractoriness, and 100-day status for engraftment, TA-GVHD, HSCT-GVHD, infections, and mortality.

RESULTS

Mean corrected count increment (× 10³ ) of 33 test PC recipients was similar (18.9 ± 8.8 vs. 16.6 ± 8.4; p = 0.296) to that of 31 control PC recipients. Test recipients had a reduced, but nonsignificant, incidence of ATR (test = 9.1%, Control = 19.4%; p = 0.296). The frequencies of clinical refractoriness (0 of 33 vs. 4 of 31 patients) and refractory transfusions (6.6% vs. 19.3%) were lower in the test cohort (p = 0.05 and 0.02), respectively. No patient in either cohort had TA-GVHD. Day 100 engraftment, HSCT-GVHD, mortality, and infectious disease complications were similar between cohorts.

CONCLUSIONS

This study indicated that A-PR PC without LR, gamma irradiation, or bacterial screening is feasible for support of HSCT.

Efforts Toward Elimination of Infectious Agents in Blood Products

The US blood supply has never been safer. This level of safety depends on a multifaceted approach including blood donor screening, sensitive infectious disease testing, and good manufacturing practice. However, risks remain for transfusion-transmitted infections due to bacterial contamination of platelets and emerging diseases. Thus, ongoing improvements in screening and testing are required. Newer pathogen reduction technologies have shown promise in further ameliorating the safety of the blood supply.

Transfusion-transmitted CMV infection - current knowledge and future perspectives

Transmission of human cytomegalovirus (CMV) via transfusion (TT-CMV) may still occur and remains a challenge in the treatment of immunocompromised CMV-seronegative patients, e.g. after stem cell transplantation, and for low birthweight infants. Measures to reduce the risk of TT-CMV have been evaluated in clinical studies, including leucocyte depletion of cellular blood products and/or the selection of CMV-IgG-negative donations. Studies in large blood donor cohorts indicate that donations from newly CMV-IgG-positive donors should bear the highest risk for transmitting CMV infections because they contain the highest levels of CMV-DNA, and early CMV antibodies cannot neutralise CMV. Based on this knowledge, rational strategies to reduce the residual risk of TT-CMV using leucoreduced blood products could be designed. However, there is a lack of evidence that CMV is still transmitted by transfusion of leucoreduced units. In low birthweight infants, most (if not all) CMV infections are caused by breast milk feeding or congenital transmission rather than by transfusion of leucoreduced blood products. For other patients at risk, no definitive data exist about the relative importance of alternative transmission routes of CMV compared to blood transfusion. As a result, only the conduction of well-designed studies addressing strategies to prevent TT-CMV and the thorough examination of presumed cases of TT-CMV will achieve guidance for the best transfusion regimen in patients at risk.

Determination of the Biological Form of Human Cytomegalovirus DNA in the Plasma of Solid-Organ Transplant Recipients

Background

Whether cytomegalovirus (CMV) DNA exists in plasma as virion-associated or free DNA is uncertain.

Methods

An assay combining DNase I digestion and CMV quantitative polymerase chain reaction (DNase-CMV-qPCR) was developed to differentiate free naked DNA from virion DNA. One hundred three frozen and 10 fresh CMV DNA-positive plasma samples from solid-organ transplant recipients (SOTRs) were tested. Three sets of paired qPCR (P-qPCR) assays with amplicons of variable length were used to study CMV DNA fragmentation in 20 SOTR plasma samples, viral stocks (Towne, Merlin, AD169) and the first World Health Organization (WHO) international standard (IS) for CMV DNA.

Results

In all plasma samples, 98.8%-100% of CMV DNA was free DNA; this was the only form in 93 of 103 (90.3%) frozen and all 10 fresh samples tested using DNase-CMV-qPCR. Low levels of virion CMV DNA were found in 10 of 103 (9.7%) samples with higher total DNA load. Cytomegalovirus DNA results were highly reproducible for 3 CMV virus stocks and WHO IS (P > .80), tested by three sets of paired q-PCR. However, for the 20 SOTR plasma samples, the smaller amplicon assay result was 2.6-fold, 3.4-fold, and 6.5-fold higher than the longer amplicion result (P < .001).

Conclusions

Cytomegalovirus DNA in SOTR plasma is almost exclusively free DNA, highly fragmented, and not virion associated.

Postnatal cytomegalovirus infection: a pilot comparative effectiveness study of transfusion safety using leukoreduced-only transfusion strategy

BACKGROUND

The optimal mitigation strategy to prevent transfusion transmission of cytomegalovirus (TT-CMV) in preterm very low birthweight infants remains debated. Hospitals caring for this patient population have varied practices.

STUDY DESIGN AND METHODS

A prospective observational comparative effectiveness pilot study was conducted to determine the feasibility for a larger study. The pilot was carried out at hospitals using a leukoreduction (LR)-only transfusion strategy. Specimen and data collection for this study was performed in a similar approach to a study completed at Emory University that employed the CMV-seronegative plus LR approach. All testing was performed at one laboratory. The rates of TT-CMV using the two transfusion strategies were compared.

RESULTS

Zero incidence of TT-CMV was detected in infants (n = 20) transfused with LR-only blood (0/8; 95% confidence interval [CI], 0-25.3%) and is consistent with the previously reported zero incidence of TT-CMV finding in a cohort of infants transfused with CMV-negative plus LR blood (0/310; 95% CI, 0%-0.9%). The seroprevalence rate among enrolled mothers (n = 17) was 60%. Forty percent of those infants (8/20) received 43 transfusions; five were transfused with one or more CMV-seropositive blood components. One infant had tested positive for CMV before receiving blood transfusions; the infant's mother was CMV immunoglobulin (Ig)G positive and IgM negative.

CONCLUSIONS

Using the LR-only transfusion approach, zero cases of TT-CMV were detected in this pilot study. A larger study is needed to reliably determine the most effective strategy for prevention of TT-CMV in this population.

Cytomegalovirus transmission in pediatric renal transplant recipients during the window period

We report two CMV naïve children who received deceased donor renal transplants from a CMV IgG-negative single donor. CMV IgG in both recipients and the donor were negative immediately prior to transplant. Both recipients had early recurrences of their original disease in their transplants, requiring multiple sessions of plasmapheresis. All blood products used were leukoreduced or CMV seronegative. A few days post-transplant, both recipients developed significant positive CMV viremia. Both required initiation of oral valganciclovir. Case 1 responded to oral valganciclovir only while the case 2 had a delayed response to it and hence required intravenous ganciclovir with good response. When checked retrospectively, CMV IgM in the donor was positive along with positive CMV DNA PCR from the white cells. Here we describe a very unusual scenario of CMV transmission in two pediatric renal transplant recipients from a single donor during the CMV window period.

Leucoreduction of blood components: an effective way to increase blood safety?

Over the past 30 years, it has been demonstrated that removal of white blood cells from blood components is effective in preventing some adverse reactions such as febrile non-haemolytic transfusion reactions, immunisation against human leucocyte antigens and human platelet antigens, and transmission of cytomegalovirus. In this review we discuss indications for leucoreduction and classify them into three categories: evidence-based indications for which the clinical efficacy is proven, indications based on the analysis of observational clinical studies with very consistent results and indications for which the clinical efficacy is partial or unproven.

Transfusion support issues in hematopoietic stem cell transplantation

BACKGROUND

Patients receiving hematopoietic stem cell transplantation require extensive transfusion support until red blood cell and platelet engraftment occurs. Rare but predictable complications may arise when the transplanted stem cells are incompatible with the native ABO type of the patient. Immediate and delayed hemolysis is often seen.

METHODS

A literature review was performed and the results from peer-reviewed papers that contained reproducible findings were integrated.

RESULTS

A strong body of clinical evidence has developed around the common complications experienced with ABO-incompatible hematopoietic stem cell transplantation. These complications are discussed and the underlying pathophysiology is explained. General treatment options and guidelines are enumerated.

CONCLUSIONS

ABO-incompatible hematopoietic stem cell transplantations are frequently performed. Immune-related hemolysis is a commonly encountered complication; therefore, health care professionals must recognize the signs of immune-mediated hemolysis and understand the various etiologies that may drive the process.

Systematic Evaluation of Different Nucleic Acid Amplification Assays for Cytomegalovirus Detection: Feasibility of Blood Donor Screening

Acute primary cytomegalovirus (CMV) infections, which commonly occur asymptomatically among blood donors, represent a significant risk for serious morbidity in immunocompromised patients (a major group of transfusion recipients). We implemented a routine CMV pool screening procedure for plasma for the identification of CMV DNA-positive donors, and we evaluated the sensitivities and performance of different CMV DNA amplification systems. Minipools (MPs) of samples from 18,405 individual donors (54,451 donations) were screened for CMV DNA using the RealStar CMV PCR assay (Altona Diagnostic Technologies), with a minimum detection limit of 11.14 IU/ml. DNA was extracted with a high-volume protocol (4.8 ml, Chemagic Viral 5K kit; PerkinElmer) for blood donor pool screening (MP-nucleic acid testing [NAT]) and with the Nuclisens easyMAG system (0.5 ml; bioMérieux) for individual donation (ID)-NAT. In total, six CMV DNA-positive donors (0.03%) were identified by routine CMV screening, with DNA concentrations ranging from 4.35 × 10(2) to 4.30 × 10(3) IU/ml. Five donors already showed seroconversion and detectable IgA, IgM, and/or IgG antibody titers (IgA(+)/IgM(+)/IgG(-) or IgA(+)/IgM(+)/IgG(+)), and one donor showed no CMV-specific antibodies. Comparison of three commercial assays, i.e., the RealStar CMV PCR kit, the Sentosa SA CMV quantitative PCR kit (Vela Diagnostics), and the CMV R-gene PCR kit (bioMérieux), for MP-NAT and ID-NAT showed comparably good analytical sensitivities, ranging from 10.23 to 11.14 IU/ml (MP-NAT) or from 37.66 to 57.94 IU/ml (ID-NAT). The clinical relevance of transfusion-associated CMV infections requires further investigation, and the evaluated methods present powerful basic tools providing sensitive possibilities for viral testing. The application of CMV MP-NAT facilitated the identification of one donor with a window-phase donation during acute primary CMV infection.

One size will never fit all: the future of research in pediatric transfusion medicine

There is concern at the National Heart, Lung, and Blood Institute (NHLBI) and among transfusion medicine specialists regarding the small number of investigators and studies in the field of pediatric transfusion medicine (PTM). Accordingly, the objective of this article is to provide a snapshot of the clinical and translational PTM research considered to be of high priority by pediatricians, neonatologists, and transfusion medicine specialists. Included is a targeted review of three research areas of importance: (i) transfusion strategies, (ii) short- and long-term clinical consequences, and (iii) transfusion-transmitted infectious diseases. The recommendations by PTM and transfusion medicine specialists represent opportunities and innovative strategies to execute translational research, observational studies, and clinical trials of high relevance to PTM. With the explosion of new biomedical knowledge and increasingly sophisticated methodologies over the past decade, this is an exciting time to consider transfusion medicine as a paradigm for addressing questions related to fields such as cell biology, immunology, neurodevelopment, outcomes research, and many others. Increased awareness of PTM as an important, fertile field and the promotion of accompanying opportunities will help establish PTM as a viable career option and advance basic and clinical investigation to improve the health and wellbeing of children.

Impact of socioeconomic risk factors on the seroprevalence of cytomegalovirus infections in a cohort of pregnant Polish women between 2010 and 2011

The purpose of this investigation was to perform an evaluation of the prevalence and socioeconomic risk factors for human cytomegalovirus (HCMV) infections in a cohort of Polish pregnant women between 2010 and 2011. HCMV-specific IgG and IgM antibody levels were assayed with enzyme-linked immunosorbent assay (ELISA) tests in serum samples collected from 1,250 pregnant women attending outpatient obstetric clinics and hospitalized at two hospitals in Lodz. The seroprevalence of anti-HCMV IgG and IgM antibodies was 62.4 and 2.2 %, respectively, and differed significantly between age-stratified groups (p ≤ 0.05). The highest IgG prevalence was observed in women above 36 years of age (76.2 %) and IgM in adolescent women aged 16–20 years (6.0 %). Of the various socioeconomic factors, age above 36 years, basic and professional education, and offspring were significantly associated with HCMV IgG prevalence rates (PRs; 1.89, 1.80, and 1.56, respectively). Financial status, occupational risk related to contact with children, and transfusions were not related to the prevalence of IgG antibodies. The IgM prevalence was not associated with any of the analyzed risk factors. A slightly higher prevalence was observed in women who were transfused in the past, but the relationship was not significant. The current data have revealed a decrease in HCMV IgG seroprevalence in our region during recent years (62.4 vs. 76.7 %). Basic and professional education, as well as bringing up offspring, were determined as significant risk factors for HCMV infections in Polish pregnant women [risk ratio (RR) 1.20 and 1.17, respectively], suggesting that the primary and secondary prophylaxis of cytomegaly is necessary during pregnancy, even if screening is not mandatory.

Prevention of Transfusion-Transmitted Cytomegalovirus Infections: Which is the Optimal Strategy?

Traditionally, leukoreduction and selection of blood products from seronegative donors have been used as alternative strategies to reduce the risk of transfusion-transmitted cytomegalovirus infections (TT-CMV) in atrisk patients. After the introduction of universal leukoreduction for red blood cell and platelet concentrates in Germany, a controversy evolved as to whether the additional selection of blood products from seronegative donors would reduce or even increase the risk of TT-CMV. This review summarizes the current knowledge about CMV infections in blood donors and the implications of this information on the effect of potential transfusion strategies. Even though there are conflicting data about the incidence of TT-CMV remaining after the introduction of leukodepletion, it has been clearly shown that both prevalence and concentration of CMV DNA in peripheral blood are highest in newly seropositive donors. Therefore, avoidance of blood products from these donors is the most important goal of any transfusion strategy. This goal can be reached by: i) selection of blood products from seronegative donors, ii) provision of CMV DNA-negative blood products, or iii) provision of blood from long-term seropositive donors. In cases of suspected TT-CMV, all implicated donors should be investigated carefully to gather further knowledge on which donors confer the lowest risk for TT-CMV.

Neopterin in Diagnosis and Monitoring of Infectious Diseases

Neopterin is produced by activated monocytes, macrophages, and dendritic cells upon stimulation by interferon gamma produced by T-lymphocytes. Quantification of neopterin in body fluids has been achieved by standard high-performance liquid chromatography, radioimmunoassays, and enzyme-linked immunosorbent assays. Neopterin levels predict HIV-related mortality more efficiently than clinical manifestations. Successful highly active antiretroviral therapy is associated with a decrease in neopterin levels. Elevated neopterin levels were associated with hepatitis by hepatitis A, B, and C viruses. Serum neopterin levels were found to be a predictor of response to treatment of chronic HCV infection with pegylated interferon combined with ribavirin. Neopterin levels of patients with pulmonary tuberculosis were found to be higher in patients with more extensive radiological changes. Elimination of blood donors with elevated neopterin levels to reduce risk of transmission of infections with known and unknown viral pathogens has been undertaken. Neopterin measurement is hereby more cost effective but less sensitive than screening using polymerase chain reaction based assays. In conclusion neopterin is a nonspecific marker of activated T-helper cell 1 dominated immune response. It may be a useful marker for monitoring of infectious disease activity during treatment and for more accurate estimation of extent of disease and prognosis.

Cytomegalovirus (CMV) seroprevalence in Japanese blood donors and high detection frequency of CMV DNA in elderly donors

BACKGROUND

The current prevalence of cytomegalovirus (CMV) in Japan and the risk of CMV transfusion transmission are unknown in the era of seronegative leukoreduced blood components.

STUDY DESIGN AND METHODS

We measured CMV-specific immunoglobulin (Ig)M and IgG in 2400 samples of whole blood collected from 12 groups of blood donors categorized by sex and age at 10-year intervals from their teens to their 60s. We also tested for CMV DNA using polymerase chain reaction in the cellular fractions of all samples.

RESULTS

We found that 76.6% of blood donors were CMV seropositive. The seroprevalences among donors in their 20s and 30s were 58.3 and 73.3%, respectively. We detected CMV DNA in the cellular fraction of 4.3% of samples from donors in their 60s and in 1.0% of samples from donors younger than 60 years. None of the 562 seronegative samples was DNA positive. Furthermore, 14% of DNA-positive samples also contained DNA in the plasma fraction, and two of five such samples were derived from donors in their 60s. Leukoreduced plasma components derived from donations with CMV DNA in plasma samples also contained a relevant amount of CMV DNA.

CONCLUSION

The seroprevalence of CMV among Japanese blood donors of child-bearing age has not changed over the past 15 years. Latent CMV becomes reactivated more frequently among elderly donors than among younger donors. A proportion of them have free CMV DNA in their plasma fraction, which could not be diminished by leukoreduction. The risk of transfusion-transmitted CMV infection in blood with plasma CMV DNA should be determined.

The impact of donor cytomegalovirus DNA on transfusion strategies for at-risk patients

BACKGROUND

Cytomegalovirus (CMV) DNA is frequently detected in plasma of newly seropositive donors. Selection of leukoreduced blood products from donors with remote CMV infection could avoid transfusion-transmitted CMV infections (TT-CMV) due to primarily infected donors. However, there are no data about the prevalence of reactivations in long-term seropositive donors compared to the incidence of window period donations in seronegative donors. Therefore, the optimal transfusion strategy for at-risk patients is unclear.

STUDY DESIGN AND METHODS

Whole blood samples from 22,904 donations were tested for CMV DNA, and CMV DNA-positive donations were categorized as donations from 1) seronegative donors, 2) newly seropositive donors, and 3) long-term seropositive donors.

RESULTS

Twenty-one donors were reproducibly CMV DNA-positive (0.09%). Frequency of detection and concentration of CMV DNA in whole blood were comparable for seronegative and long-term seropositive donors. Nonreproducibly positive results for CMV DNA in whole blood were more frequent in long-term seropositive donors (0.16% vs. 0.01%, p<0.01). Only low concentrations of CMV DNA in plasma were detectable in two seronegative donors and one long-term seropositive donor. Highest concentrations of CMV DNA in both whole blood and plasma, however, were found in newly seropositive donors.

CONCLUSION

Prevalences of window period donations among seronegative donors and reactivations among long-term seropositive donors, as well as the CMV DNA concentration in whole blood and plasma samples from these donors, are comparable. Therefore, blood products from both groups could be used for patients at risk for TT-CMV, while those of newly seropositive donors seem to bear an increased risk.

Reconstitution of protective immune responses against cytomegalovirus and varicella zoster virus does not require disease development in pediatric recipients of umbilical cord blood transplantation

CMV and varicella zoster virus (VZV) are significant causes of morbidity and mortality following umbilical cord blood transplantation (UCBT). However, the kinetics of reconstitution and protective potential of antiviral cell-mediated immune responses following UCBT remain poorly characterized. In this study, the reconstitution of CMV- and VZV-specific T cell responses was assessed using IFN-γ ELISPOT in 28 children who underwent UCBT to treat hematological or inherited disorders. Barely detectable in the first 3 mo posttransplantation, CMV- and VZV-specific T cell responses were observed in 30.4% and 40.3% of study subjects after 36 mo of follow-up. Four of five CMV-seropositive subjects developed detectable levels of circulating CMV DNA (DNAemia), and 5 of 17 VZV-seropositive patients experienced herpes zoster during the posttransplant period. Four CMV-seronegative subjects developed IFN-γ responses against CMV, and four subjects developed a VZV-specific IFN-γ response without clinical signs of infection. No CMV- or VZV-related events were observed in study subjects following the development of CMV- or VZV-specific responses > 150 spot-forming units/10(6) PBMCs, consistent with T cell-mediated protection. Finally, famciclovir prophylaxis did not strictly prevent the reconstitution of the VZV-specific T cell repertoire, because the frequency of T cells producing IFN-γ in response to VZV Ags reached levels consistent with protection in two nonzoster subjects. Monitoring of CMV- and VZV-specific cell-mediated immunity could inform immunocompetence and guide the initiation and cessation of antiherpetic prophylaxis in UCBT recipients.

Alternative blood products and clinical needs in transfusion medicine

The primary focus of national blood programs is the provision of a safe and adequate blood supply. This goal is dependent on regular voluntary donations and a regulatory infrastructure that establishes and enforces standards for blood safety. Progress in ex vivo expansion of blood cells from cell sources including peripheral blood, cord blood, induced pluripotent stem cells, and human embryonic stem cell lines will likely make alternative transfusion products available for clinical use in the near future. Initially, alloimmunized patients and individuals with rare blood types are most likely to benefit from alternative products. However, in developed nations voluntary blood donations are projected to be inadequate in the future as blood usage by individuals 60 years and older increases. In developing nations economic and political challenges may impede progress in attaining self-sufficiency. Under these circumstances, ex vivo generated red cells may be needed to supplement the general blood supply.

Prolonged recovery from pediatric cardiac surgery due to disseminated cytomegalovirus infection

Partial atrioventricular septal defect is usually followed by an uncomplicated postoperative course. We present an infant with unexplained persistent respiratory failure following partial a trioventricular septal defect repair. Extensive evaluation including bronchoalveolar lavage subsequently led to the diagnosis of disseminated cytomegalovirus. This is the first reported case to our knowledge of disseminated cytomegalovirus following surgical repair of congenital heart disease excluding orthotopic heart transplant.

[Pediatric transfusion practices: A single-center retrospective study]

OBJECTIVES

This study aimed to describe the professional practices in pediatric transfusion to assess the accuracy of transfusion guidelines in children.

METHODS

The study retrospectively analyzed the characteristics of all the pediatric transfusions prescribed in the Clermont-Ferrand (France) university hospital center over 1 year and determined whether they conformed to the national guidelines.

RESULTS

One thousand six hundred and seven blood products were delivered to 233 children (806 red cell units, 670 platelet units, and 131 plasma units), accounting for 5.3% of the center's whole blood products. Transfusions were mainly prescribed by the oncohematology unit (68.2%), the intensive care unit (15.4%), and for surgery (10.2%). Ten adverse events were reported in eight patients (0.6% of transfusions). The prescription conformed to the national guidelines in 35.9%, 41.6%, and 80.9% of the red blood cell, platelet, and plasma unit transfusions, respectively. Nonconformity was mainly due to abusive irradiation and "cytomegalovirus seronegative" specifications.

CONCLUSION

Malignancies, intensive care, and surgery are the main indications for transfusion in children. Substantial discrepancy between recommendations and actual practices was observed. This illustrates the variability of risk evaluation. This should be made simpler by the use of photochemical pathogen inactivation techniques.

Transmission of cytomegalovirus (CMV) infection by leukoreduced blood products not tested for CMV antibodies: a single-center prospective study in high-risk patients undergoing allogeneic hematopoietic stem cell transplantation (CME)

BACKGROUND

Measures to prevent transfusion-transmitted cytomegalovirus (TT-CMV) infection after hematopoietic stem cell transplantation (HSCT) include transfusion of CMV antibody-negative blood units and/or transfusion of leukoreduced cellular blood products. We assessed the incidence of TT-CMV in CMV-seronegative patients receiving CMV-seronegative HSC transplants, who were transfused with leukoreduced cellular blood products not tested for anti-CMV.

STUDY DESIGN AND METHODS

In a prospective observational study between 1999 and 2009, all HSCT patients received leukoreduced cellular blood products not tested for anti-CMV. Patients were screened for CMV serostatus and CMV-negative recipients of CMV-negative transplants were systematically monitored for TT-CMV clinically and by CMV nucleic acid testing. Anti-CMV antibodies (immunoglobulin [Ig]G and IgM) were assessed after three time intervals (Interval 1, study inclusion to Day +30 after HSCT; Interval 2, Day +30-Day +100; Interval 3, after Day +100).

RESULTS

Among 142 patients treated with allogeneic HSCT, 23 CMV-negative donor-patient pairs were identified. These 23 patients received 1847 blood products from 3180 donors. All patients remained negative for CMV DNA and none developed CMV-associated clinical complications. This results in a risk for TT-CMV per donor exposure of 0% (95% confidence interval, 0.0%-0.12%). However, 17 of 23 patients seroconverted for anti-CMV IgG, but none for anti-CMV IgM. CMV IgG seroconverters received significantly more transfusions per week than nonconverters.

CONCLUSION

The risk of TT-CMV is low in high-risk CMV(neg/neg) HSCT patients transfused with leukoreduced blood products not tested for anti-CMV. The cause of anti-CMV IgG seroconversion is most likely passive antibody transmission by blood products.

A novel set of real-time PCRs for rapid differentiation between human cytomegalovirus wild-type and highly passaged laboratory strains

Restricting amplification of human cytomegalovirus (HCMV) DNA to wild-type (WT) HCMV is useful to exclude PCR contaminations by laboratory strains from viral cultures. A set of UL141-specific TaqMan PCRs was developed to amplify (1) WT HCMV and laboratory strain Towne(long), but not strain AD169, (2) only WT HCMV. The performance was compared to a PCR targeting the conserved sequence of HCMV glycoprotein B using 46 serum and urine samples from blood donors with primary CMV infection. Amplification was restricted to the targeted strains with the exception of Towne(long) being amplified also by PCR (2), but at a distinctly lower efficiency than WT HCMV. The coefficient of regression for linear dilutions of two clinical samples with a high concentration of HCMV DNA was 0.999 and 0.997, respectively. The correlation between both WT PCRs and the generic HCMV PCR was good, with coefficients of regression of 0.891 and 0.871 for PCR (1) and (2), respectively. The limit of detection was calculated to be 1.5 genome equivalents per PCR. The set of HCMV TaqMan PCRs enables rapid differentiation between WT and laboratory strains, which can be especially useful as even virus lysate can contaminate sensitive PCRs without prior DNA isolation. A standardized WT HCMV control would be useful to evaluate WT-specific PCR methods.

Evaluation of neopterin levels in patients undergoing hemodialysis

Neopterin is a diagnostic or a prognostic biomarker for several pathologies including renal diseases. However, the association between neopterin status and causative main reasons such as diabetes and hypertension for renal disease remains unclear. The aim of the study was to evaluate neopterin levels in diabetes and hypertension patients treated with/without hemodialysis. According to primary renal disorders, the patients undergoing hemodialysis were classified into 4 groups as diabetic nephropathy, hypertensive nephropathy, reflux nephropathy or interstitial nephritis, and others. The controls consisted of healthy subjects, hypertensive subjects, and diabetic individuals without any renal disorder. In the study, both urinary and serum neopterin levels were measured using high performance liquid chromatography and enzyme-linked immunosorbant assay in patients undergoing regular hemodialysis therapy (n=71). The effects of the duration of hemodialysis and treatment of erythropoietin and/or iron on neopterin levels were also evaluated. Neopterin levels were found to be higher in hemodialysis patients than in the healthy controls (P<0.05). A significant difference in neopterin levels was also found between diabetic control patients and diabetic nephropathy patients (P<0.05). A similar significant difference was detected in neopterin levels between hypertensive patients with/without nephropathy (P<0.05). Neopterin may be an early critical marker for progression of nephropathy in diabetic and hypertensive patients in early stages.

The natural course of primary cytomegalovirus infection in blood donors

BACKGROUND AND OBJECTIVES

As cytomegalovirus (CMV) DNA is frequently detectable in the plasma of recently infected sero-positive blood donors, information concerning primary CMV infection is important for the identification of possibly infectious donors.

MATERIALS AND METHODS

Monitoring of 17 982 donors for CMV antibodies and DNA in plasma identified 14 subjects with ongoing primary CMV infection. Thirteen donors were interrogated for possible sources of infection and CMV-related symptoms, and monitored for CMV antigens, CMV DNA in plasma, leucocytes and urine, course of IgG and IgM antibodies as well as markers of systemic infection and parameters of organ function.

RESULTS

CMV antigens and DNA were detectable in peripheral blood for up to 54 and 269 days respectively. Clearance of CMV DNA from blood correlated with clearance of IgM antibodies, development of IgG antibodies against the membrane glycoprotein gB and development of high avidity IgG antibodies. Eighty-five percent of subjects with primary CMV infection, but even 69% of matched controls reported possibly CMV-related symptoms. Sixty-two and 23%, respectively, had contact with possible sources of infection. One donor developed a febrile illness accompanied by increased levels of CMV DNA in peripheral blood 2 to 3 weeks after seroconversion. In other donors, neither markers of systemic infection nor parameters of organ function correlated with the course of CMV DNA and antigens.

CONCLUSION

Potentially infectious donors can be identified by measuring CMV DNA, IgM antibodies or avidity of IgG antibodies. Alternatively, blood products donated during the first year after seroconversion should not be used for immunocompromised patients.

Cytomegalovirus seroprevalence and ‘cytomegalovirus-safe’ seropositive blood donors

Cytomegalovirus (CMV) seroprevalence was determined in 9343 first-time New Zealand blood donors between 2003 and 2006. Of 39 960 current seropositive donors the proportion testing seropositive more than 12 months previously was calculated. Overall, seroprevalence declined from 66·1% [95% confidence interval (CI) 64·1–68·1] in 2003 to 60·6% (95% CI 58·5–62·6) in 2006. Nevertheless, these rates are significantly higher than the 47% overall seroprevalence found in a 1988 study. Seroprevalence was higher in females than males and in older than in younger age groups in all four years examined. Ethnicity appeared to be related to seroprevalence with the highest rates found in Pacific Islanders (93·2%) and the lowest in Caucasians (54·8%). At least 38 242/39 960 (95·7%) seropositive donors were found to have seroconverted more than 12 months previously. Recent evidence suggests that such ‘remote’ seroconverters may pose a much lower risk of transfusion-transmitted CMV infection than recently infected seroconverting, but seronegative, blood donors.

Increased mortality in long-term intensive care patients with active cytomegalovirus infection

OBJECTIVE

To determine the prevalence and impact on patient outcome of active human cytomegalovirus infections in patients with prolonged treatment in an intensive care unit.

DESIGN

Retrospective analysis of stored plasma samples.

SETTING

Anesthesiological intensive care unit of a university hospital.

PATIENTS

All 138 patients treated for at least 14 days (of a total of 4940 patients admitted during the study period). Immunocompromised patients and patients with inconclusive results for cytomegalovirus DNA were excluded.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Stored plasma samples of patients with prolonged intensive care unit stay were tested for cytomegalovirus DNA. Sixty-four of 255 evaluable samples from 99 immunocompetent patients tested cytomegalovirus DNA-positive with a mean DNA concentration of 8,600 genome equivalents per milliliter. Active cytomegalovirus infection was diagnosed by reproducibly positive results in 35 patients (35%). Only one case had been diagnosed clinically. Patients with and without active cytomegalovirus infection were not significantly different in parameters, such as age, sex, admission category, source of admission, or comorbidities. Even review of specific surgical procedures or the use of a heart-lung-machine showed no significant differences between the groups. The mortality rate in patients with cytomegalovirus infection was significantly increased (28.6% vs. 10.9%, p = 0.048), and surviving patients had a longer intensive care unit stay (32.6 vs. 22.1 days, p <0.001).

CONCLUSIONS

Active cytomegalovirus infection is a frequent but seldom diagnosed finding in surgical patients with prolonged intensive care unit stay, which is associated with increased mortality and prolonged intensive care unit stay of surviving patients.