Neural Transplantation in Huntington's Disease: The NEST-UK Donor Tissue Microbiological Screening Program and Review of the Literature

Neural transplantation of human fetal tissue for Huntington's disease (HD) is now entering the clinical arena. The safety of the procedure has now been demonstrated in a number of studies, although the efficacy of such an approach is still being investigated. Stringent but practicable screening of the donor tissue for potential pathogens is an essential prerequisite for successful implementation of any novel transplant program that uses human fetal tissue. In this article we summarize the UK-NEST protocol for the screening of human fetal tissue being grafted to patients with mild to moderate HD. We describe the results of microbiological screening of 87 potential tissue donors in a pilot study, and of the first four donor–recipient patients included in the UK-NEST series. The rationale for the adoption and interpretation of the various tests is described and our methodology is compared with those previously used by other centers. This article therefore presents a comprehensive, logical yet pragmatic screening program that could be employed in any clinical studies that use human fetal tissue for neurotransplantation.

A case of transfusion-acquired hepatitis C

The Blood Transfusion Service introduced screening for Hepatitis C antibody (HCV) in September 1991. This is done by second generation enzyme linked immunosorbent assay (ELISA) tests. We present a case of post-transfusion hepatitis C hepatitis in a patient with myeloma. Infection was acquired before screening was introduced. Both the patient and the infected blood donor were diagnosed using ELISA assays and the polymerase chain reaction (PCR). In this way we prevented the blood donor from spreading the virus via subsequent blood donations. There were some interesting discrepancies in the HCV assays. Blood samples, when tested by different methods, gave both positive and negative results. The results also varied according to when the blood samples to be tested were taken. The case illustrates the importance of confirming positive results and that no single laboratory test is entirely satisfactory in diagnosing HCV infection.

An internally controlled, one-step, real-time RT-PCR assay for norovirus detection and genogrouping

BACKGROUND

Reverse transcription (RT)-PCR for norovirus detection is prone to false-negative results due to inhibitory substances in faeces. An internal control is needed to monitor extraction efficiency and to detect inhibition.

OBJECTIVES

To further develop a one-step RT-PCR assay for norovirus detection/genogrouping by addition of MS2 bacteriophage as an internal control.

STUDY DESIGN

Our norovirus RT-PCR assay was modified by addition of MS2 phage to the extraction tray and primers/probe for MS2 detection to the reaction mix. The effect of addition of MS2 phage and MS2 primers/probe on the sensitivity/specificity of the PCR assay was examined.

RESULTS

The addition of MS2 as an internal control showed no loss of sensitivity or specificity for norovirus detection.

CONCLUSIONS

A triplex, one-step, type-specific, real-time RT-PCR with MS2 internal control has been developed for use in routine laboratory diagnosis of norovirus infection.

Investigation of a hepatitis A outbreak in a primary school by sequential saliva sampling

BACKGROUND

An outbreak of hepatitis A occurred in a primary school (children aged 4-11 years), starting in the Autumn of 1990 and terminating some 5 months later after some spread into the local community.

OBJECTIVES

The objectives were to monitor the spread of the virus within the primary school over time, to document infection in asymptomatic individuals and the efficacy of using saliva for HAV antibody detection in young children as an acceptable screening method by using the Salivette method and ordinary cotton tipped swabs.

STUDY DESIGN

Serial saliva samples were taken over a period of months and anti-HAV IgM and IgG antibodies measured by radioimmunoassay.

RESULTS

Twenty-seven children in the school and nine individuals from the surrounding community acquired hepatitis A. Twenty-one (78%) of the 27 children were symptomatic, as were all the affected adults. The cotton-tipped swabs were found to be as effective a method as Salivette at diagnosing infection in those in whom the methods were compared.

CONCLUSIONS

Despite many reports stating that children are more likely to be asymptomatic with HAV infection we found the majority to report significant symptoms. Young children do not easily accept serum sampling as a method for diagnosis or epidemiological studies, and we show that saliva sampling is an effective and acceptable diagnostic method.

Cytomegalovirus infection in immunocompetent patients

Symptoms associated with cytomegalovirus (CMV) infection in immunocompetent patients are not well documented. From December 1998 through June 2001, serum samples obtained from 7630 patients in Cambridge and Chelmsford, United Kingdom, were tested for CMV immunoglobulin M. CMV immunoglobulin G avidity was used to confirm CMV infection. A total of 124 patients (106 patients treated by general practitioners [GPs] and 18 hospitalized patients) with CMV infection were identified. The most frequent symptoms were malaise (67%), fever (46%), and sweats (46%), and the most frequent finding was abnormal liver function test results (69%). Twelve percent of patients had a relapsing illness, and many had symptoms that lasted for up to 32 weeks (mean duration of symptoms, 7.8 weeks). GPs reported that there was a significant benefit in making the diagnosis of CMV infection; it provided reassurance and avoided the need for further investigations. We have identified symptoms associated with CMV infection in immunocompetent patients who present to GPs or who are admitted to the hospital.

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.

Laboratory policies on testing for rotavirus affect surveillance data. PHLS East Epidemiology and Virology Subcommittees

The effect of different laboratory testing policies on the surveillance of rotavirus was assessed in eight laboratories between 1995 and 1998. In 1995, five laboratories tested all faecal specimens from children aged 5 years and under all year, two tested all specimens from children aged 4 years and under all year, and one tested all specimens from children aged 3 years and under between November and May only. Five laboratories changed their testing policy between 1995 and 1998. By 1998, three tested all specimens from children aged 5 years and under all year and two from the same age group during the 'season' only. Three laboratories had unique policies: one tested all specimens from children aged 2 years and under between January and June, one tested all specimens from children aged 4 years and under all year, and one tested specimens only on clinical request. The onset date of the rotavirus infection 'season' as determined by retrospective scrutiny of reported cases varied by up to 15 weeks between laboratories, starting as early as week 45 (November) and as late as week 13 (March). Laboratories with more restrictive testing policies yielded fewer reports of rotavirus and changes in policy within a particular laboratory affected the number of reports. Temporal and geographic trends were visible, even within the relatively small area covered by this study, and showed how laboratory testing policies affect surveillance data.

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.

A randomized trial of solvent/detergent-treated and standard fresh-frozen plasma in the coagulopathy of liver disease and liver transplantation

BACKGROUND

Virus inactivation of pooled fresh-frozen plasma (FFP) by the solvent/detergent (SD) method results in a loss of approximately 20 percent of factor VIII. This study aimed to assess the efficacy of SD-treated plasma in correcting the coagulopathy associated with liver disease and liver transplantation.

STUDY DESIGN AND METHODS

Forty-nine patients with coagulation deficits due to liver disease, who required FFP for invasive procedures or liver transplantation, were randomly assigned to receive either FFP or SD-treated plasma. Patients were assessed for side effects, correction of coagulopathy over 24 hours, and seroconversion for viral markers 6 to 18 months after treatment.

RESULTS

In the liver disease group, equal correction of clotting factors and partial thromboplastin time was seen with FFP and SD-treated plasma, with a similar return to baseline values over 24 hours. There was greater correction of the International Normalised Ratio in patients receiving SD-treated plasma (p = 0.037), but this patient group had higher baseline values than recipients of FFP (p = 0.024). Liver transplant patients also showed equivalent correction of coagulopathy with the same dose of FFP and SD-treated plasma. The use of other blood components during transplantation was identical in the two treatment groups. No seroconversions were seen for HIV or hepatitis B or C virus. One patient who had received FFP seroconverted for human parvovirus B19. Apparent seroconversion for hepatitis A virus seen at 9 to 13 months in four other patients was probably due to detection of passively transferred antibodies, as later testing of these patients gave negative results. Minor side effects were rare in both groups.

CONCLUSION

SD-treated plasma is an efficacious source of coagulation factors for patients with liver disease who are undergoing biopsy or transplantation. Assessment of seroconversion for viral markers in recipients of plasma-derived products and plasma components should include consideration of the possibility that passively transferred antibodies were detected.

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.

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.

Intravenous ganciclovir prophylaxis for cytomegalovirus in heart, heart-lung, and lung transplant recipients

Cytomegalovirus (CMV) disease has had a significant clinical impact on the heart, heart-lung and lung transplant recipients in our centre. CMV disease has been so severe with CMV antibody-negative heart-lung transplant patients receiving organs from CMV antibody-positive donors (CMV-mismatched patients) that in 1986 we adopted the policy of not transplanting CMV-positive organs into CMV-negative heart-lung or lung recipients. In December 1992, we instituted a policy of providing intravenous ganciclovir (5 mg/kg twice a day for 28 days) during the immediate postoperative period for CMV-mismatched heart recipients and CMV antibody-positive heart-lung and lung patients, who have been the patients at greatest risk of severe CMV disease in our centre. A placebo group was not employed because of ethical considerations, ganciclovir having been shown to be effective for the treatment of CMV infections among transplant patients. Compared with a historical control group of patients receiving no prophylaxis, prophylactic ganciclovir reduced the incidence of CMV infection (39 % vs 91 %, P = 0.0006) and CMV disease (17 % vs 74 %, P = 0.0004) among CMV antibody-positive heart-lung recipients. Prophylactic ganciclovir did not significantly reduce the incidence of CMV infection or disease among heart or isolated lung recipients. Ganciclovir was well tolerated, with few adverse reactions. In the case of heart-lung transplant patients, one month of intravenous prophylactic ganciclovir significantly reduced the incidence of both CMV infection and disease when compared with patients who received no prophylaxis. With the lung transplant and heart transplant patients, there were no significant differences between the prophylaxis and nonprophylaxis groups, although there was a consistent trend towards less infection and disease in the prophylaxis groups.

Blood-borne virus infections in dialysis units--a review

Hepatitis outbreaks in haemodialysis unit patients and staff were reported in the late 1960s. In 1972, the Rosenheim report in the UK established guidelines which included routine tests for hepatitis B surface antigen and isolation facilities for dialysing patients with hepatitis B virus which resulted in a dramatic fall in cases of hepatitis. However, since these guidelines were introduced, other blood-borne viruses, notably HCV and HIV have been discovered, and failures of infection control practices still lead to outbreaks of HBV in haemodialysis units. The prevalence of HCV in dialysis patients varies considerably throughout the world, with reported prevalence ranging from 3.9% to 71%. The number of blood transfusions and the length of time on dialysis have consistently been associated with HCV prevalence. Several reports provide evidence of patient-to-patient HCV transmission with environmental blood contamination the most significant factor in intra-unit transmission. There is no evidence that HCV has been transmitted by re-use of dialysis machines but being dialysed next to an HCV positive patient is associated with a significant risk of HCV acquisition. Several studies have shown that dialysing HCV positive patients in a separate unit or in a defined sector of a dialysis unit significantly reduces nosocomial HCV infection. HGV is prevalent in dialysis units where there is evidence of transmission to patients but no evidence of associated symptoms. HIV is infrequently transmitted in dialysis units and several units treating many HIV-positive patients have shown no evidence of transmission. Careful attention needs to be paid to infection control procedures and regular virological testing.

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.

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.

Q fever in pregnancy

We describe a case of acute symptomatic infection with Coxiella burnetii acquired between the 16th and 28th week of pregnancy. Oral ciprofloxacin therapy was started on diagnosis, at the 28th week of pregnancy, but symptoms were unabated after 3 weeks treatment, suggesting persisting infection of the products of conception. Caesarean section was therefore performed at 32 weeks gestation when a healthy infant was delivered, and subsequent investigations showed no evidence of transplacental spread of infection. Infection control measures were applied at the time of delivery to minimize the risk of infection to obstetricians and midwives from potentially infectious products of conception.

An analysis of infection control of varicella-zoster virus infections in Addenbrooke's Hospital Cambridge over a 5-year period, 1987-92

This prospective study analyses infections with varicella-zoster virus (VZV) in Addenbrooke's Hospital, Cambridge during 1987-92 and examines the spread of infection. In total, 93 patients and staff experienced VZV infection. Twenty-one patients had varicella and 49 experienced zoster. None of 101 patients and 1 of 625 staff members in contact with varicella cases acquired infection. By contrast, 2 of 227 patients, and 5 of 1039 staff in contact with zoster cases acquired varicella. One out of 28 (3.6%) VZV antibody-negative patients and staff in contact with varicella acquired infection, compared with 5 out of 29 (17.2%) VZV antibody-negative patients and staff in contact with zoster. Thus, zoster was found to be a more frequent cause of nosocomial infection than varicella. Fourteen members of staff had VZV infection during the study period. One of 99 patients and none of 389 staff members in contact with these cases developed varicella. The cost of dealing with infection control for VZV infections in our hospital is estimated to be Pounds 714 per patient case and a total of Pounds 13,204 per year.

Hepatitis B virus surface mutations associated with infection after liver transplantation

BACKGROUND/AIMS

Liver transplantation for chronic liver disease due to hepatitis B virus infection is associated with a high risk of graft infection, graft failure and death. Many centres restrict this procedure to those seronegative for HBV-DNA (by hybridisation assay) and use prophylactic polyclonal human hepatitis B specific immunoglobulin to prevent infection of the graft, despite the very high cost.

METHODS

We describe three patients who underwent liver transplantation for chronic HBV-related disease in whom death was due to fibrosing cholestatic hepatitis following graft infection with hepatitis B virus, despite receiving hepatitis B specific immunoglobulin. Variation within the immunodominant a epitope of HBsAg was sought by analysis of hepatitis B virus sequences and the use of a point mutation assay, following amplification from serum by the polymerase chain reaction.

RESULTS

Prior to transplantation, Cases 1 and 2 had mutations at nucleotide 1902 (codon 145), resulting in G-C substitutions, which persisted at a low level after transplantation. In Case 2 a second mutant type with a G-A substitution at nucleotide 1902, became the predominant viral type post transplant. Case 3 had exclusively wild type virus before and after transplantation. The emergence of mutant type virus in Case 2 may have occurred because of immune pressure exerted by high titre anti-HBs detectable for more than 7 months. Cases 1 and 3 received only brief courses of anti-HBs therapy. The mutant viral surface antigen was not detected by a monoclonal antibody-based assay, and therefore the choice of HBsAg assay for post-transplant monitoring of patients who receive liver grafts for hepatitis B virus disease is important.

CONCLUSIONS

A search for mutations affecting the a determinant prior to liver transplantation for HBV-related liver disease may help to identify those at risk of failure of prophylaxis. Monoclonal antibodies specific to the codon 145-mutant surface antigen might prevent graft infection, but other mutations might then emerge.

Blood cyclosporine concentrations and cytomegalovirus infection following heart transplantation

We have attempted to identify major risk factors for cytomegalovirus (CMV) infection and disease following heart transplantation, with emphasis on the degree and type of immunosuppression used. One hundred and eleven consecutive heart transplant recipients were studied for the first 4 months. Data from the 95 who survived at least 1 month were analyzed using multiple Cox regression. Blood cyclosporine concentrations (CsAbc) > 550 micrograms L-1 were associated with a 4.4-fold increase in risk of CMV infection during the next week (95% confidence interval = 1.2-16.2). Other significant risk factors for CMV infection included antirejection treatment in the past 14 days, a drop in white blood cell count, receiving a CMV antibody-positive donor organ, and primary diagnosis other than cardiomyopathy. We found that patients experiencing a CMV infection were at 3 times the risk of subsequently developing symptomatic CMV disease (95% confidence interval = 1.1-9.7). In addition, the proportion of patients developing symptomatic CMV disease was significantly higher amongst those with a median CsAbc > 550 micrograms L-1 for at least 1 week (29% vs. 10%; P = 0.02) or who had been treated for rejection more frequently than once every 6 weeks (31% vs. 12%; P = 0.04) during the first 4 months. CMV antibody-negative recipients of antibody-positive donor organs had a higher rate of symptomatic CMV disease than did other serological combinations (67% vs. 10%; P = 0.0001). We conclude that the risk of CMV infection and symptomatic disease following heart transplantation may be critically influenced by early management of immunosuppression as well as by donor serology.

Serological reactivity against cyst and tachyzoite antigens of Toxoplasma gondii determined by FAST-ELISA

AIMS

To obtain quantitative data on the human serological response to Toxoplasma gondii tachyzoite and bradyzoite antigens.

METHODS

Serum samples from 30 patients who had positive antibody titres against T gondii and from 14 who were seronegative, together with sequential serum samples from four infected individuals, were screened by FAST-ELISA.

RESULTS

Serum samples from the 30 seropositive patients showed high IgG and IgM titres against the T gondii tachyzoite antigen but very low responses to cyst antigen. This result was borne out in sequential serum samples from patients with toxoplasmosis.

CONCLUSION

Antibody recognition of the cystic stage of T gondii is low, implying that either this stage is poorly immunogenic or that the antigen load is low.

Epstein-Barr virus infection in heart and heart-lung transplant recipients: incidence and clinical impact

BACKGROUND

A retrospective serologic study was made of 67 heart-lung and 295 heart transplant recipients (with transplantations at Papworth Hospital, Cambridge, England) to determine the incidence and clinical impact of Epstein-Barr virus infection.

METHODS

Epstein-Barr virus capsid antigen immunofluorescence tests were performed, and the antibody avidity was determined by modifying the washing procedure to include a mild reducing agent (8M urea).

RESULTS

This testing showed that 6.0% of the patients had primary Epstein-Barr virus infections, whereas 17.4% had the reactivation of a past infection. Primary infections were only detected in patients who were Epstein-Barr virus antibody-negative before transplantation, who had received an organ from an Epstein-Barr virus antibody-positive donor. Of the patients with serologically proven Epstein-Barr virus infections, 52.9% had symptoms. Although these were generally mild, five heart and two heart-lung transplant recipients had malignant lymphoma and one heart and one heart-lung transplant recipient had lymphoproliferative disease after Epstein-Barr virus infection. Additional four heart transplant recipients had lymphoma after transplantation. None of these four patients had evidence of active Epstein-Barr virus infection; one was Epstein-Barr virus antibody-negative during the study period and three had stable Epstein-Barr virus virus capsid antigen immunoglobulin G titers throughout.

CONCLUSIONS

Epstein-Barr virus infection in organ transplant recipients may lead on to life-threatening lymphoproliferative disease or lymphoma. For this reason it may be beneficial to monitor patients after transplantation for evidence of Epstein-Barr virus infection and to follow the progress of those affected.

Testing for HIV antibody: a comparison of two services offered in a genitourinary medicine clinic

Rates of screening for sexually transmissible infections in patients using different services provided by a genitourinary medicine clinic for testing for HIV antibodies are presented. Those patients whose primary reason for attending the clinic was HIV antibody testing and used the same day result (SDR) service were significantly less likely to be screened for other infections than those using the normal waiting time (NWT) service, (P < 0.00001). This was true for both males and females. Of those patients screened for other infections in the SDR and NWT groups 29% and 35% respectively were found to have a sexually transmitted infection. It would appear that an SDR service offers little benefit for the majority of patients as only a few patients would not have had an HIV antibody test had the SDR not been available.

Internal quality assurance in a clinical virology laboratory. II. Internal quality control

AIMS

In April 1991 additional quality control procedures were introduced into the virology section of the Clinical Microbiology and Public Health Laboratory, Cambridge. Internal quality control (IQC) samples were gradually included in the serological assays performed in the laboratory and supplemented kit controls and standard sera.

METHODS

From April 1991 to December 1993, 2421 IQC procedures were carried out with reference sera.

RESULTS

The IQC samples were evaluated according to the Westgard rules. Violations were recorded in 60 of 1808 (3.3%) controls and were highest in the IQC samples of complement fixation tests (25/312 (8%) of controls submitted for complement fixation tests).

CONCLUSIONS

The inclusion of IQC samples in the serological assays performed in the laboratory has highlighted batch to batch variation in commercial assays. The setting of acceptable limits for the IQC samples has increased confidence in the validity of assay results.

Internal quality assurance in a clinical virology laboratory. I. Internal quality assessment

AIMS

In April 1991 an internal quality assessment scheme (IQAS) was introduced into the virology section of the Clinical Microbiology and Public Health Laboratory, Cambridge. The IQAS was established to identify recurring technical and procedural problems, to check the adequacy of current techniques, and to calculate the frequency of errors.

METHODS

Between April 1991 and December 1993, 715 anonymous clinical serum samples were submitted to the laboratory to test 3245 individual procedures of diagnostic viral serology.

RESULTS

A total of 485 (14.9%) procedural and 61 (1.9%) technical discrepancies were observed, the technical discrepancies mainly being recorded in complement fixation tests. Twenty two (0.7% of total procedures) of the technical discrepancies were diagnostically significant.

CONCLUSIONS

Evaluation criteria developed with the introduction of IQAS to viral serology, and technical and procedural discrepancies are assessed. As yet, IQAS has not been introduced to other sections of the diagnostic virology laboratory (virus isolation, electron microscopy, immunofluorescence, and enzyme linked immunosorbent assays for viral and chlamydial antigens).

Hepatitis C virus infections in transplant patients: serological and virological investigations

Hepatitis C virus (HCV) is transmitted by organs of HCV antibody-positive donors to transplant recipients. This study investigated the serological and virological responses of 14 initially HCV antibody-negative transplant patients who received organs from four HCV antibody-positive donors (A-D) (before donor screening for HCV infection was introduced in 1991). Second generation HCV enzyme immunoassay (Abbott HCV EIA) was used to detect anti-HCV antibody. Recombinant immunoblot (RIBA-2; Chiron Corporation) and Wellcozyme Western blot (Wwb) assays were compared as confirmatory assays of positive EIA results. Reverse transcription (RT) followed by "nested" polymerase chain reaction (PCR) was performed to detect viral RNA. HCV RNA was only found in the sera of donors B and C, however, transplantation of organs from all donors resulted in infection of all recipients. HCV RNA was found in recipient sera within 30 days after transplant and remained detectable throughout the period of sampling. An anti-HCV antibody response was found in only 6 (of the 14) recipients and only after 300 days. Much longer periods passed before detection of HCV antibody in six recipients. For detection of HCV infection in transplant recipients it is essential that testing for HCV RNA by RT-PCR is carried out.

Transmission of hepatitis C virus by organ transplantation in the United Kingdom

This study employed a second-generation anti-HCV ELISA, and a second-generation recombinant immunoblot assay and hepatitis C virus RNA detection by polymerase chain reaction to investigate the anti-HCV prevalence in 554 British organ donors and the transmission of hepatitis C virus to heart, liver and kidney recipients between 1984 and 1991. Serum samples from six (1.08%) donors were reactive in the second-generation anti-HCV ELISA and four (67%) of these gave positive or indeterminate results in the recombinant immunoblot assay-2. Of the 15 recipients of these organs from hepatitis C virus-confirmed positive/indeterminate donors, 14 (93%) acquired hepatitis C virus infection and seven (47%) had evidence of hepatitis C virus-related liver disease after transplantation and no evidence of blood transfusion-related transmission. Only six of the 15 (40%) recipients had detectable anti-HCV after transplantation, while 12 of 14 (86%) patients tested had hepatitis C virus RNA in their serum detectable by "nested" polymerase chain reaction. These data indicate a very high rate of transmission with a major risk of the development of liver disease. We believe our study supports the testing of all British organ donors for anti-HCV and that organs from anti-HCV-positive patients should not be transplanted unless the recipient has life-threatening disease and there is a donor shortage, when their use may be justified. Since there are time constraints on organ donor testing, which may frequently be done on call during unsocial hours, we would recommend second-generation ELISA as the current screening test of choice.(ABSTRACT TRUNCATED AT 250 WORDS)

Seroepidemiological associations between tuberculosis, malaria, hepatitis B, and AIDS in West Africa

Serum samples from 51 patients with malaria, 35 patients with hepatitis B virus infection, 111 patients with tuberculosis, and 166 healthy controls were studied to determine any associations between tuberculosis, malaria, hepatitis B, and AIDS in Nigeria, West Africa. All serum samples were examined for the presence of HIV-1/HIV-2, hepatitis B virus surface antigen (HBsAg), and malaria antibodies. Only one patient was HIV-1 antibody-positive and none HIV-2 antibody-positive. Statistical associations were found between the presence of malaria antibody titres on the one hand and a diagnosis of hepatitis B virus infection (P < 0.05) or tuberculosis (P < 0.05). A stronger association (P < 0.001) was found between the presence of HBsAg and tuberculosis suggesting that HBsAg carriers are at higher risk of contracting tuberculosis.

Serum folate and chronic fatigue syndrome

We assayed serum folate levels of 60 patients with chronic fatigue syndrome (CFS) and found that 50% had values below 3.0 micrograms/l. Some patients with CFS are deficient in folic acid.

Efficacy of pyrimethamine for the prevention of donor-acquired Toxoplasma gondii infection in heart and heart-lung transplant patients

Seven (11%) of the first 65 patients who received heart transplants at Papworth Hospital were mismatched for Toxoplasma gondii. Of these, four (57%) experienced T. gondii infection and two died. The remaining two had severe symptoms and received anti-T-gondii chemotherapy for a year after transplantation. In an attempt to reduce the impact of donor-acquired T. gondii in our heart transplant recipients, we decided in April 1984 to give prophylactic pyrimethamine to all T. gondii-mismatched patients. In this study, 7 years later, we review the efficacy of this policy. Five of 37 (14%) patients given prophylactic pyrimethamine acquired T. gondii infection; only one was symptomatic, and none died. This compares with 100% symptomatic infection in the pre-1984 patients, who did not receive prophylactic pyrimethamine. We believe that our experience has shown that pyrimethamine is effective in reducing the incidence and severity of primary donor-acquired T. gondii infection in mismatched heart and heart-lung transplant recipients.

Donated organ as a source of cytomegalovirus in orthotopic liver transplantation

The importance of the donated organ as a source of CMV was assessed in 120 patients following orthotopic liver transplant and the CMV infections that developed in these patients were graded by severity. Forty-four recipients were CMV antibody negative pre-transplant. Eighteen of these received organs from CMV antibody positive donors and 15 (83%) developed primary CMV infections, 13 (87%) of which were symptomatic. Twenty-six received organs from CMV antibody negative donors and only 2 (8%) became CMV positive post transplant (P less than 0.001). These data suggest that there would be a considerable advantage in matching CMV antibody negative recipients with negative donors. Forty-five percent of secondary infections were asymptomatic compared with 12% of primary infections, and only 11% became disseminated compared with 53% of primary infections. The secondary infections that followed transplantation of an organ from a CMV antibody positive donor were more likely to be symptomatic and were more severe than those in patients who received seronegative livers.

Cytomegalovirus infection in heart-lung transplant recipients: risk factors, clinical associations, and response to treatment

The risk factors, clinical associations, and response to treatment of cytomegalovirus (CMV) pneumonia and infection were studied in 65 recipients of heart-lung transplantation. There were 29 episodes of CMV pneumonia in 22 patients. In 80% (20/25) of episodes of CMV pneumonia treated with intravenous ganciclovir, the histologic changes resolved and the patient survived. Among seronegative recipients, a seropositive donor was a significant risk factor for CMV pneumonia and infection in the first 90 days after heart-lung transplantation (P = .004 and .002, respectively). Among seropositive recipients, there was no additional risk associated with a sero-positive donor. Rates of CMV pneumonia and infection were significantly increased when treatment with augmented immunosuppression had been given in the preceding 30 days (P less than .001). A significant association was found between CMV pneumonia or infection and pulmonary bacterial infections occurring 30 days before or after such an episode (P less than .001).

Infection and reactivation with cytomegalovirus strains in lung transplant recipients

Cytomegalovirus pneumonia is a major cause of morbidity and death following lung transplantation (LT) (1). The case fatality rate is highest in the CMV-seronegative recipients (R-) of organs from seropositive donors (D+), which suggests that transmission of CMV may occur with the graft (1), but in seropositive recipients (R+) the comparative importance of reactivation of endogenous virus and reinfection with donor virus is poorly understood.

Hepatitis A outbreak involving bread

An outbreak of hepatitis A involved more than 50 residents of a group of villages in the late spring and summer of 1989. The only food that was common to all the laboratory-confirmed cases was bread, purchased either unwrapped or as rolls, sandwiches or filled rolls, and supplied either directly from one shop or indirectly through its subsidiary outlets. It was concluded that this bread was the most likely vehicle of transmission of the hepatitis A virus and that the bread was contaminated by soiled hands which were inadequately washed because of painful skin lesions. Comprehensive control measures were successful in limiting further spread of the infection. This outbreak highlights the transmissibility of hepatitis A virus on food. The use of disposable gloves when handling food which is to be consumed without further cooking would prevent transmission of this or other infectious agents by this route.

A rapid micro-agglutination technique for the detection of antibody to Legionella pneumophila serogroup 5

A rapid micro-agglutination test (RMAT) for the detection of antibody to Legionella pneumophila serogroup 5 is described. It was found to be both sensitive and specific when compared with the indirect immunofluorescence test. Evaluation of 89 paired sera from patients with respiratory symptoms showed that the incidence of L. pneumophila serogroup 5 respiratory infection in East Anglia is low: only one case was found in this study. The RMAT would be easy to perform as a screening test in a routine serological laboratory.