Biomedical subjects

P C Evans

Publications and source records attributed to P C Evans.

At least 19 recordsLinked to original sources

PubMed2005

Donor CD31 genotype and its association with acute graft-versus-host disease in HLA identical sibling stem cell transplantation.

CD31 gene polymorphisms are implicated in the pathogenesis of graft-versus-host disease (GvHD) following haematopoietic stem cell transplantation (HST). We investigated the influence of CD31 genotype on the incidence of GvHD following HST from an human leukocyte antigen (HLA)-identical sibling donor. Donor and recipient CD31 codons 125, 563 and 670 DNA polymorphisms were determined in 85 cases of HLA identical sibling HST from two transplant centres. A correlation between CD31 genotype and acute GvHD was considered significant if observed in patients from both transplant centres independently. A strong correlation was identified between donor CD31 codon 125 genotype and the incidence of acute GvHD. Acute GvHD grades II-IV occurred in 27 of 46 (59%) recipients with a CD31 codon 125 leucine / valine heterozygous donor compared to nine of 39 (23%) recipients with a CD31 codon 125 homozygous donor (P=0.0019, relative-risk 2.45, 95% confidence interval 1.3-4.5). This correlation was significant in patients from both transplant centres (P=0.015 and P=0.019). We suggest that CD31 genotype may influence the function of donor-derived leukocytes and may be informative when there is a choice of comparable donors.

Acute Disease↗

PubMed2001

Isolation and characterization of two novel A20-like proteins.

The transcription factor nuclear factor kappa B (NF-kappa B) plays a pivotal role in inflammatory processes through induction of adhesion molecules and chemokines. The zinc finger molecule A20 is an important negative regulator of NF-kappa B. The mechanism utilized by A20 is not fully understood, but A20 has been shown to bind to tumour-necrosis-factor-receptor-associated factor (TRAF) molecules, which are necessary for pro-inflammatory cytokine signalling. We report two novel genes, Cezanne (cellular zinc finger anti-NF-kappa B) and TRABID (TRAF-binding domain), with sequence similarity to A20. Co-immunoprecipitation studies indicated that TRAF6 was able to interact with both Cezanne and TRABID. In contrast, reporter gene experiments revealed a specific ability of Cezanne to down-regulate NF-kappa B. It is likely, therefore, that Cezanne participates in the regulation of inflammatory processes.

Amino Acid Sequence↗

PubMed2001

Signaling through CD31 protects endothelial cells from apoptosis.

Endothelial damage has been implicated in the pathogenesis of chronic rejection. Conversely, expression of protective genes [including A20, A1, bcl-xl, and hemoxygenase-1 (HO-1)] in the endothelium has been associated with long-term graft survival. Overexpression of protective genes in cultured endothelial cells confers protection from apoptosis and prevents expression of inflammatory molecules through inactivation of NF-kappaB. CD31 (PECAM-1) expressed at endothelial cell junctions is ligated by leukocytes during transendothelial migration. Our laboratory has recently shown that cross-linking CD31 using a monoclonal antibody (LCI-4) triggers signaling events in endothelial cells. In this study, we demonstrate that treatment with LCI-4 protected serum-starved endothelial cells from apoptosis. CD31 cross-linking also led to elevation of A20 and A1 mRNA levels and activation of the transcription factor Sp-1. In summary, signaling through CD31 on endothelial cells leads to protection from apoptosis in association with up-regulation of two protective molecules, A20 and A1.

Animals↗

PubMed2001

Recipient HLA-DR3, tumour necrosis factor-alpha promoter allele-2 (tumour necrosis factor-2) and cytomegalovirus infection are interrelated risk factors for chronic rejection of liver grafts.

BACKGROUND/AIMS: The tumour necrosis factor (TNF)-2 promoter allele, which elicits elevated expression of TNF-alpha, is in linkage disequilibrium with the extended haplotype HLA-A1-B8-DR3-DQ2. TNF-2 and HLA-DR3 have been implicated in renal and cardiac graft rejection and loss. Cytomegalovirus (CMV) infection has been associated with chronic allograft rejection. We examined the relationship between HLA-DR3, promoter allele TNF-2 and cytomegalovirus in relation to chronic rejection following liver transplantation. METHODS: (i) Retrospective analysis of HLA-DR3 was performed in 307 liver transplant recipients and 283 donors. (ii) Prospective analysis of TNF-alpha promoter allele status, HLA-DR3 status and cytomegalovirus infection was assessed in 123 recipients. RESULTS: (i) Retrospective analysis. Recipient HLA-DR3 (relative risk 1.9; 95% C.I. 1.01-3.58) was a risk factor for chronic rejection. (ii) Prospective analysis. Recipient HLA-DR3 was a risk factor for chronic rejection (relative risk 3.41; 95% C.I. 1.66-7.03) which was elevated further by superimposed CMV infection (relative risk 5.01; 95% C.I. 2-12.55). Recipient TNF-2 was associated with chronic rejection (relative risk 2.29; 95% C.I. 0.9-5.83) through linkage to HLA-DR3. CONCLUSIONS: Recipient HLA-DR3, TNF-2 status and CMV infection were inter-related risk factors for chronic rejection of liver grafts.

Adolescent↗

PubMed2000

Interleukin-13 protects endothelial cells from apoptosis and activation: association with the protective genes A20 and A1.

BACKGROUND: Chronic rejection is the major obstacle to long-term survival of allografts and is associated with graft endothelial cell activation and apoptosis. Recent reports have found an association between graft survival, presence of Th2 cytokines, and expression by endothelial cells of cytoplasmic "protective" molecules that prevent apoptosis and down-regulate the inflammatory process. METHODS: Cultured human umbilical vein endothelial cells (HUVEC) were used. Apoptotic cells were detected by staining with FITC-annexinV followed by flow cytometry. Expression of vascular cell adhesion molecule-1, E-selectin, and intercellular adhesion molecule-1 were also measured by flow cytometry. Transcripts were detected by reverse transcription-PCR and quantitation was achieved by co-amplification of competing, internal standard RNA. RESULTS: We demonstrate that exposure of HUVEC to interleukin (IL)-13 for 72 hr afforded partial protection from apoptosis induced by tumor necrosis factor-alpha/cycloheximide or serum starvation. Pretreatment with IL-13 also modulated induction of E-selectin after acute exposure to tumor necrosis factor-alpha or IL-1alpha. Protection was associated with transcription of the genes A1 and A20. Prolonged treatment with IL-13 had minimal proinflammatory effects and did not induce expression of E-selectin or vascular cell adhesion molecule-1 or increase intercellular adhesion molecule-1 above basal levels. CONCLUSIONS: Our data provide a possible explanation for the observed association between Th2 cytokines and expression of protective genes in the endothelium of long-surviving allografts and xenografts.

Apoptosis↗

PubMed2000

Cutting edge: persistent fetal microchimerism in T lymphocytes is associated with HLA-DQA1*0501: implications in autoimmunity.

The host's MHC genotype plays a critical role in susceptibility to autoimmune diseases. We previously proposed that persistent fetal microchimerism from pregnancy contributes to the pathogenesis of autoimmune diseases such as scleroderma. In the current study, we investigated whether the specific host MHC genotype is associated with persistent microchimerism among T lymphocytes in women with scleroderma and in healthy women. Fetal microchimerism among T lymphocytes was strongly associated with HLA DQA1*0501 of the mother (odds ratio (OR) = 13.5, p = 0.007, p corrected (pc) = 0.06) and even more strongly with DQA1*0501 of the son (OR = infinity; p = 0. 00002, pc = 0.0002). This is the first description of an association between persistent fetal microchimerism in maternal T lymphocytes and specific HLA class II alleles. Although the association was observed in both healthy women and in women with scleroderma, the finding suggests an additional route by which HLA genes might contribute to susceptibility to autoimmune disease.

Adolescent↗

PubMed2000

An association between cytomegalovirus infection and chronic rejection after liver transplantation.

BACKGROUND: Previous studies suggest a link between cytomegalovirus (CMV) infection and chronic rejection. Since these studies, more sophisticated diagnostic methods with high sensitivity and specificity for CMV have been developed and effective therapy/prophylaxis for CMV is now available. We sought CMV prospectively by polymerase chain reaction of serum and urine and by conventional methods in a group of 33 patients undergoing 57 transplants during 1993 or 1994, selected from a larger series. There were 13 grafts lost to chronic rejection. The remaining 44 grafts that did not develop chronic rejection served as controls and comprised 15 successful primary grafts, 15 second transplants, 8 third transplants, and 6 primary grafts that were lost for reasons other than chronic rejection. RESULTS: The combination donor CMV antibody negative with recipient antibody positive and the duration of CMV infection >30 days were associated with an increased relative risk of chronic rejection. In contrast, the presence of CMV infection alone, symptomatic CMV infection, the detection of CMV by PCR of serum or urine, and the peak/cumulative viral load were not predictive. CMV infection occurred earlier in those undergoing a second transplant for chronic rejection than for those undergoing a second transplant for other reasons. In addition, a human leukocyte antigen B mismatch was associated with prolonged CMV infection. CONCLUSION: These data are consistent with the hypothesis that prolonged subclinical cytomegalovirus infection is associated with an increased risk of chronic rejection.

Adolescent↗

PubMed2000

Effect of IGF-I on serine metabolism in fetal sheep.

Acute infusion of IGF-I to the fetus has been shown to inhibit amino acid oxidation and appears to increase fetoplacental amino acid uptake. This study was designed to investigate further the effects of IGF-I on fetal amino acid metabolism. Radiolabeled serine was used to test the hypothesis that fetal IGF-I infusion enhances serine uptake into the fetus and/or placenta and inhibits serine oxidation. Eight fetal sheep were studied at 127 days of gestation before and during a 4-h infusion of IGF-I (50 microg/h per kg). During the infusion there was no change in uptake of serine or its oxidation by fetus or placenta. However, both uptake and oxidation of serine and glycine decreased in the fetal carcass. There was also a decrease in fetal blood serine and glycine concentrations which could indicate a decrease in protein breakdown, although reduced amino acid synthesis cannot be excluded. Thus IGF-I appeared to influence the distribution of these amino acids as oxidative substrates between different fetal tissues. In addition, fetal IGF-I infusion increased the conversion of serine to glycine which is likely to have increased the availability of one-carbon groups for biosynthesis. Our data provide further evidence that IGF-I plays a role in the regulation of fetoplacental amino acid metabolism.

Animals↗

PubMed1999

Alpha-galactosyl-mediated activation of porcine endothelial cells: studies on CD31 and VE-cadherin in adhesion and signaling.

BACKGROUND: Ligation of alpha-galactosyl epitopes on endothelial cells by naturally occurring human antibodies causes hyperacute rejection in porcine-to-human xenotransplantation. The alpha-galactosyl-specific lectin Bandeiraea simplicifolia isolectin B4 (IB4) has been reported to trigger endothelial "gap" formation and tyrosine phosphorylation of an unidentified 130-kDa protein. We have studied two 130-kDa junctional adhesion molecules, CD31 and VE-cadherin, in porcine aortic endothelial cells (PAECs) during IB4-mediated activation. The cellular distribution of these molecules, their susceptibility to tyrosine phosphorylation, and their capacity to bind IB4 or natural human antibodies have been determined. METHODS: Porcine CD31 and VE-cadherin were cloned. Recombinant proteins and monoclonal antibodies were prepared. The distribution and phosphorylation of CD31 and VE-cadherin in confluent PAECs activated with IB4 or human serum were studied by confocal microscopy and Western blotting, respectively. RESULTS: IB4 caused rapid redistribution of CD31 and VE-cadherin away from cell junctions and tyrosine-phosphorylation of CD31 but not VE-cadherin. A monoclonal antibody to CD31 also triggered tyrosine phosphorylation of this molecule, but brief exposure of PAECs to normal human serum did not. Tyrosine-phosphorylated CD31 complexed with SHP2 and other unidentified phosphoproteins. Both IB4 and natural human antibodies bound to porcine CD31 but not to VE-cadherin. Cell adhesion tests showed that porcine and human CD31 are functionally incompatible. CONCLUSIONS: Endothelial cell retraction during IB4-mediated activation of PAECs is associated with rapid loss of CD31 and VE-cadherin from cell junctions. CD31 becomes strongly tyrosine-phosphorylated and forms a cell signaling complex, which may have a significant role in the response of the xenograft vascular endothelium.

Animals↗

PubMed1999

Administration of crushed extended-release pentoxifylline tablets: bioavailability and adverse effects.

The pharmacokinetics of crushed and intact pentoxifylline tablets were compared, and the frequency of adverse effects was evaluated. Intact 400-mg extended-release pentoxifylline tablets, crushed 400-mg tablets, intact 600-mg tablets, and crushed 600-mg tablets were given sequentially to 10 healthy male volunteers. Blood samples were collected at time 0, at 30-minute intervals for the first three hours, and at 4, 6, 8, 12, and 24 hours after the dose and analyzed by capillary gas chromatography for pentoxifylline and three major metabolites. The bioavailability of the crushed tablets relative to the intact tablets was 156% for the 400-mg strength and 137% for the 600-mg strength. The area under the plasma drug concentration-time curve from 0 to 24 hours (AUC0-24) for the 400-mg tablets (crushed and intact) differed significantly from that for the 600-mg tablets; there was no significant difference between intact 400-mg and intact 600-mg tablets or crushed 400-mg and crushed 600-mg tablets. The maximum plasma drug concentration (Cmax) was significantly greater and the time to maximum concentration (t(max)) significantly shorter for crushed tablets than intact tablets. The 400-mg crushed tablet caused mild nausea in three subjects. The 600-mg crushed tablet caused both moderate nausea and dizziness in seven subjects and diaphoresis, headache, and vomiting in one subject each. Cmax was higher and tmax shorter when pentoxifylline tablets were administered crushed rather than intact, and the increase in maximum plasma concentrations appeared to cause dose-related adverse effects; crushing the tablets did not decrease the relative bioavailability.

Biological Availability↗

PubMed1999

Long-term fetal microchimerism in peripheral blood mononuclear cell subsets in healthy women and women with scleroderma.

Fetal CD34(+) CD38(+) cells have recently been found to persist in maternal peripheral blood for many years after pregnancy. CD34(+) CD38(+) cells are progenitor cells that can differentiate into mature immune-competent cells. We asked whether long-term fetal microchimerism occurs in T lymphocyte, B lymphocyte, monocyte, and natural-killer cell populations of previously pregnant women. We targeted women with sons and used polymerase chain reaction for a Y-chromosome-specific sequence to test DNA extracted from peripheral blood mononuclear cells (PBMC) and from CD3, CD19, CD14, and CD56/16 sorted subsets. We also asked whether persistent microchimerism might contribute to subsequent autoimmune disease in the mother and included women with the autoimmune disease scleroderma. Scleroderma has a peak incidence in women after childbearing years and has clinical similarities to chronic graft-versus-host disease that occurs after allogeneic hematopoietic stem-cell transplantation, known to involve chimerism. Sixty-eight parous women were studied for male DNA in PBMC and 20 for PBMC subsets. Microchimerism was found in PBMC from 33% (16 of 48) of healthy women and 60% (12 of 20) women with scleroderma, P =.046. Microchimerism was found in some women in CD3, CD19, CD14, and CD56/16 subsets including up to 38 years after pregnancy. Microchimerism in PBMC subsets was not appreciably more frequent in scleroderma patients than in healthy controls. Overall, microchimerism was found in CD3, CD19, and CD14 subsets in approximately one third of women and in CD56/16 in one half of women. HLA typing of mothers and sons indicated that HLA compatibility was not a requirement for persistent microchimerism in PBMC subsets. Fetal microchimerism in the face of HLA disparity implies that specific maternal immunoregulatory pathways exist that permit persistence but prevent effector function of these cells in normal women. Although microchimerism in PBMC was more frequent in women with scleroderma than healthy controls additional studies will be necessary to determine whether microchimerism plays a role in the pathogenesis of this or other autoimmune diseases.

Adult↗

PubMed1999

Cytomegalovirus infection of bile duct epithelial cells, hepatic artery and portal venous endothelium in relation to chronic rejection of liver grafts.

BACKGROUND/AIM: Chronic rejection is an important cause of graft loss following liver transplantation. A number of risk factors for chronic rejection have been identified previously, albeit inconsistently. These include cytomegalovirus infection detected by a number of different techniques, including immunohistochemical staining and in situ hybridisation of liver grafts. However, tissue-based techniques for the detection of CMV have not been applied to grafts lost to conditions other than chronic rejection. The purpose of this study was to investigate the relationship between the presence of cytomegalovirus infection detected by in situ hybridisation and immunohistochemistry with respect to graft outcome, the presence of cytomegalovirus infection detected by other techniques and in addition, the type of infected cell. METHODS: The 29 patients studied included 15 patients who lost their primary liver graft to chronic rejection in 8 cases, to hepatic artery thrombosis in 4 cases and to causes other than chronic rejection or hepatic artery thrombosis in 3 further cases. In each case, sections containing septal or large ducts and vessels were selected (usually blocks) since these may be more representative. Needle biopsies from 14 further patients who ultimately achieved satisfactory graft function served as control tissue. Of these, ten had evidence of cytomegalovirus infection at the time of study by serum/urine PCR, DEAFF testing or seroconversion, while 4 patients had no evidence of cytomegalovirus infection according to these techniques. RESULTS: Cytomegalovirus infection was detected in the liver of 12 of the 29 patients. These included 8/15 grafts lost, which comprised 3/8 with chronic rejection, 2/3 with hepatic artery thrombosis and 3/4 with grafts lost to other causes, as well as 4/14 who retained grafts. CMV was detected most commonly in association with symptomatic infection and notably was detected only by in situ hybridisation in two cases. Predominant cell types that contained cytomegalovirus were hepatocytes and mononuclear cells. However, bile duct epithelial cells, hepatic artery endothelial cells and portal venous endothelial cells also contained cytomegalovirus in some cases. CONCLUSIONS: These data support previous studies that cytomegalovirus infection is detectable in patients with chronic rejection and are consistent with the theory that CMV is involved in chronic rejection. However, cytomegalovirus infection was detected in explanted grafts lost to conditions other than chronic rejection, and the association may not be causal but a consequence of graft injury.

Bile Ducts↗

PubMed1999

Comparison of three PCR techniques for detecting cytomegalovirus (CMV) DNA in serum, detection of early antigen fluorescent foci and culture for the diagnosis of CMV infection.

Three PCR assays were developed for detection of cytomegalovirus (CMV) DNA in serum and were evaluated with samples from organ transplant recipients. The Qiamp Blood Kit was efficient for extraction of DNA from sera. Single-round PCR of a 293-bp region of CMV DNA was sensitive and highly specific for CMV targets and was more sensitive than detection of early antigen fluorescent foci (DEAFF) testing or isolation of CMV from buffy coat by cell culture. The results of a significant proportion of buffy coat samples were not interpretable because of toxicity in conventional culture or DEAFF tests. A non-competitive quantitative PCR test and semi-quantitative PCR test for the detection of CMV DNA in serum yielded comparable results for samples taken serially from three bone marrow transplant recipients. Single-round PCR was superior to conventional techniques for the diagnosis of CMV infection, was simple to perform and was completed rapidly. The semi-quantitative technique has added advantages where quantification is important.

Adult↗

PubMed1999

Microchimerism of maternal origin persists into adult life.

Recent studies indicate that fetal cells persist in maternal blood for decades after pregnancy. Maternal cells are known to engraft and persist in infants with immunodeficiency, but whether maternal cells persist long-term in immunocompetent offspring has not specifically been investigated. We developed sensitive human leukocyte antigen-specific (HLA-specific) PCR assays and targeted nonshared maternal HLA genes to test for persistent maternal microchimerism in subjects with scleroderma and in healthy normal subjects. Nonshared maternal-specific DNA was found in 6 of 9 scleroderma patients. In situ hybridization with double labeling for X and Y chromosome-specific sequences revealed female cells in peripheral blood samples from 2 male scleroderma patients. HLA-specific PCR also frequently revealed persistent maternal microchimerism in healthy control subjects. The mean age of all subjects with maternal microchimerism was 28 years (range: 9-49 years). With few exceptions, mothers of subjects with persistent maternal microchimerism were HLA incompatible with subjects for class I and class II alleles. These results clearly indicate that HLA-disparate maternal cells can persist in immunocompetent offspring well into adult life. The biological significance of maternal microchimerism and whether it might contribute to autoimmune disease requires further investigation.

Adolescent↗

PubMed1998

Fetal growth and placental function.

Fetal growth is largely determined by the availability of nutrients to the fetus. The fetus is at the end of a supply line that ensures delivery of nutrients from the maternal/uterine circulation to the fetus via the placenta. However, this supply line can not be regarded as a linear relationship. Maternal undernutrition will not only reduce global nutrient availability but will also influence the maternal and fetal somatotrophic axis. Both endocrine systems react in a very similar way to limited substrate supply. The hormones of the fetal somatotrophic axis, and in particular insulin-like growth factor (IGF)-1, are important regulators of fetal growth. Placental function is pivotal to materno-fetal nutrient and metabolite transfer. Placental function in turn, is heavily influenced by the maternal and fetal growth hormone (GH)-IGF-1 system. The placenta itself is also an active endocrine organ and it produces a large number of hormones including GH and IGF-1 as well their corresponding receptors. Thus the placenta can no longer be considered merely a passive conduit for fetal nutrition. Rather, it is actively involved in the integration of nutritional and endocrine signals from the maternal and fetal somatotrophic axes.

Animal Nutritional Physiological Phenomena↗

PubMed1998

Microchimerism and HLA-compatible relationships of pregnancy in scleroderma.

BACKGROUND: Fetal cells can be found in the maternal circulation in most pregnancies. Fetal progenitor cells have been found to persist in the circulation of women many years after childbirth. We tested the hypothesis that microchimerism is involved in the pathogenesis of scleroderma. Scleroderma is of interest because of a strong female predilection, an increased incidence in the years after childbearing, and clinical similarities between scleroderma and chronic graft-versus-host disease after allogeneic bone-marrow transplantation. We also investigated whether HLA-compatibility of a child was associated with later development of scleroderma in the mother. METHODS: We enrolled 40 women who had previously given birth to at least one son--16 healthy controls, 17 scleroderma patients, and seven healthy sisters of patients. We used quantitative PCR to amplify a Y-chromosome-specific sequence in whole peripheral blood from these women. Also 32 controls with 58 children, and 21 scleroderma patients with 47 children were HLA genotyped. FINDINGS: The mean number of male cell DNA equivalents among controls was 0.38 cells per 16 mL whole blood (median 0 [range 0-2]) and 11.1 (6.0 [0-61]) among scleroderma patients (p = 0.0007). Controls' youngest sons were born a mean of 15.4 years previously, and scleroderma patients' sons 18.5 years previously. Some scleroderma patients had concentrations of male DNA higher than those found in most pregnant women. HLA-class II compatibility of a child from the mother's perspective was more common among scleroderma patients than among controls, but was not essential for persistence of male DNA in maternal peripheral blood. INTERPRETATION: Low concentrations of male DNA can be detected in healthy women decades after the birth of a son. Microchimerism in scleroderma patients could be secondary to the underlying disease. However, the finding that HLA class II compatibility of a child was more common for scleroderma patients than for controls, supports the possibility that microchimerism may be involved in the pathogenesis of scleroderma.

Adolescent↗

PubMed1998

Optimisation of the polymerase chain reaction and dot-blot hybridisation for detecting cytomegalovirus DNA in urine: comparison with detection of early antigen fluorescent foci and culture.

Rapid, sensitive and specific assays are required for the diagnosis of CMV infection following transplantation. We describe our experience in developing assays for detecting CMV in urine. Conventional preparation of probes cloned after amplification in E. coli led to contamination with E. coli nucleic acids; these hybridised to E. coli DNA present in urine and produced false positive results. Two CMV probes (Hind III and gL) hybridised to human DNA despite high stringency; these probes were thus unsuitable for detecting viral nucleic acids in clinical samples. A PCR derived probe from the immediate early gene of CMV detected dot-blotted CMV DNA specifically. Optimal preparation of urine for detection of CMV DNA was as follows; four freeze/thaw cycles and ultracentrifugation before in vitro proteinase K/SDS treatment, phenol:chloroform extraction, heat denaturation and direct application onto a nylon membrane. However, dot-blot hybridisation was a poor test for CMV in urine; it had low sensitivity and specificity compared with virus isolation and DEAFF. Single round PCR of a 293 bp region of CMV DNA was sensitive and specific to CMV targets. However, undiluted urine contained PCR inhibitors that could only be partly removed by using PEG precipitation. PCR of CMV DNA from urine was specific but was insensitive compared to conventional culture and DEAFF. A significant proportion of urine samples were toxic in conventional culture and DEAFF tests but, PCR of CMV DNA from urine is insensitive and despite its specificity is unlikely to be advantageous in clinical practice even when DEAFF or culture prove unreliable.

Antigens, Viral↗

PubMed1998

Qualitative and semiquantitative polymerase chain reaction testing for cytomegalovirus DNA in serum allows prediction of CMV related disease in liver transplant recipients.

AIM: To identify cytomegalovirus (CMV) infection in liver transplant recipients by polymerase chain reaction (PCR) techniques and to separate the cases in which CMV related disease will occur, for whom treatment is indicated, from those in whom infection will remain innocuous. METHODS: The combination of qualitative and semiquantitative PCR of serum and urine was assessed to determine whether these assays can identify those at risk of CMV related disease and compared their performance with conventional approaches to diagnosis. RESULTS: Qualitative PCR of serum had superior specificity, sensitivity, and positive and negative predictive values compared with urine DEAFF (detection of early antigen fluorescent foci) and PCR of urine. All episodes of CMV related disease were associated with the presence of CMV DNA by PCR in serum or urine; CMV was detected before clinical onset in 70% and 60% of cases, respectively. The period over which CMV DNA could be detected was not correlated with CMV related disease. Both peak viral load and cumulative viral load estimated using a semiquantitative PCR method on serum samples positive by the qualitative method could be used to distinguish asymptomatic infection from CMV related disease with 100% specificity and sensitivity. In contrast semiquantitative PCR of urine was of little value. CONCLUSIONS: An approach based on PCR testing with a combination of qualitative and subsequently semiquantitative serum samples would improve the diagnosis of CMV infection and aid identification of those patients at risk of CMV related disease, allowing treatment to be targeted specifically.

Adolescent↗