Determinants of protracted cytomegalovirus infection in solid-organ transplant patients.

BACKGROUND: Recurrent infection frequently follows the response to the initial treatment of cytomegalovirus (CMV) infection in solid-organ transplant (SOT) recipients. The objective of this study was to describe the course of CMV infection in SOT patients and to identify factors that would predict protracted CMV infection with recurrences. METHODS: Quantitative polymerase chain reaction (PCR) assay for CMV DNA in leukocytes and in plasma were used to assess viral load changes retrospectively in consecutive SOT patients, whose CMV infection episodes had been attended therapeutically or preemptively using quantitative blood culture. RESULTS: Among 101 SOT patients, CMV infection occurred in 63, of whom 32 developed recurrent infection after the initial episode. In patients with recurrent infection, PCR indicated that a majority (27) of recipients had high level of CMV DNA in peripheral blood leukocytes and plasma throughout a protracted (>/=1 month) period including after preemptive or therapeutic ganciclovir courses. Predictors of protracted high-level infection were increasing age, CMV donor seropositivity, and all measures of viral load during the initial episode. CMV recipient seropositivity protected strongly against protracted infection. End of treatment plasma CMV DNA best discriminated between patients who did or did not develop protracted infection. CONCLUSIONS: In SOT patients, protracted CMV infection is associated with increasing age, donor seropositivity, recipient seronegativity, and high viral load during the first episode. End of therapy plasma CMV DNA level best predicts the occurrence of protracted infection. In patients with a high risk of protracted infection, prophylaxis is likely to be particularly cost effective.

Interactions of processed Nef (58-206) with virion proteins of HIV type 1.

The Nef protein plays a major role in vivo in promoting HIV and SIV replication and pathogenesis. In vitro, Nef has been shown to down-regulate cell surface molecules, such as CD4 and MHC-I, alter T cell signaling, and enhance virion infectivity. These effects are attributed to interactions of Nef with cellular proteins. In addition, HIV Nef is incorporated into viral particles, mainly localizing in the virion cores. However, no report has been published to date regarding Nef interactions with virion proteins. By immunoprecipitation, Nef was found to bind to viral enzymes. Using yeast two-hybrid and GST pulldown procedures to find out direct potential partners of Nef, Nef was consistently found to interact with viral integrase (IN). The interaction between Nef and IN was stronger when Nef was present as the viral protease-cleaved isoform. We hypothesize that the interaction of Nef with viral integrase or other virion proteins may explain the presence of Nef in viral cores. In addition, this interaction suggests that Nef may accompany the reverse transcription and the preintegration complexes during the early steps of the infection cycle and potentially affect infectivity during these steps.

An adenovirus-based fluorescent reporter vector to identify and isolate HIV-infected cells.

A procedure is described that allows the simple identification and sorting of live human cells that transcribe actively the HIV virus, based on the detection of GFP fluorescence in cells. Using adenoviral vectors for gene transfer, an expression cassette including the HIV-1 LTR driving the reporter gene GFP was introduced into cells that expressed stably either the Tat transcriptional activator, or an inactive mutant of Tat. Both northern and fluorescence-activated cell sorting (FACS) analysis indicate that cells containing the functional Tat protein presented levels of GFP mRNA and GFP fluorescence several orders of magnitude higher than control cells. Correspondingly, cells infected with HIV-1 showed similar enhanced reporter gene activation. HIV-1-infected cells of the lymphocytic line Jurkat were easily identified by fluorescence-activated cell sorting (FACS) as they displayed a much higher green fluorescence after transduction with the reporter adenoviral vector. This procedure could also be applied on primary human cells as blood monocyte-derived macrophages exposed to the adenoviral LTR-GFP reporter presented a much higher fluorescence when infected with HIV-1 compared with HIV-uninfected cells. The vector described has the advantages of labelling cells independently of their proliferation status and that analysis can be carried on intact cells which can be isolated subsequently by fluorescence-activated cell sorting (FACS) for further culture. This work suggests that adenoviral vectors carrying a virus-specific transcriptional control element controlling the expressions of a fluorescent protein will be useful in the identification and isolation of cells transcribing actively the viral template, and to be of use for drug screening and susceptibility assays.

Seroepidemiology of Herpes Simplex virus type 1 and 2 in Western and Southern Switzerland in adults aged 25-74 in 1992-93: a population-based study.

BACKGROUND: Genital herpes is one of the most prevalent sexually-transmitted diseases, and accounts for a substantial morbidity. Genital herpes puts newborns at risk for very severe disease and also increases the risk of horizontal HIV transmission. It thus stands as an important public health problem. The recent availability of type-specific gG-based assays detecting IgG against HSV-1 and HSV-2 allows to establish the prevalence of each subtype. Worldwide, few data have been published regarding the seroprevalence in general populations of HSV-2, the major causative agent for genital herpes, while no data exist regarding the Swiss population. METHODS: To evaluate the prevalence of IgG antibodies against HSV-1 and HSV-2 in Switzerland, we used a population-based serum repository from a health examination survey conducted in the Western and Southern area of Switzerland in 1992-93. A total of 3,120 sera were analysed by type-specific gG-based ELISA and seroprevalence was correlated with available volunteers characteristics by logistic regression. RESULTS: Overall, seroprevalence rates were 80.0 +/- 0.9% (SE, 95% CI: 78.1-81.8) for HSV-1 and 19.3 +/- 0.9% (SE, 95% CI: 17.6-21.1) for HSV-2 in adults 35-64 year old. HSV-1 and HSV-2 seroprevalence increased with age, with a peak HSV-2 seroprevalence in elderly gentlemen, possibly a seroarcheological evidence of sexually transmitted disease epidemics during World War II. Risk factors for HSV-2 infection included female sex, marital status other than married, and size of town of residence larger than 1500 inhabitants. Unexpectedly and conversely to HSV-1, HSV-2 seroprevalence increased with educational level. HSV-2 infection was less prevalent among HSV-1 infected individuals when compared to HSV-1 uninfected individuals. This effect was most apparent among women at high risk for HSV-2 infection. CONCLUSIONS: Our data demonstrate that by the early nineties, HSV-2 had spread quite largely in the Swiss population. However, the epidemiology of HSV-2 in Switzerland presents paradoxical characteristics, e.g. positive correlation with education level, that have not been observed elsewhere.

Seroepidemiology of herpes simplex virus type 1 and 2 in pregnant women in Switzerland: an obstetric clinic based study.

OBJECTIVE: To assess the seroprevalence of herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) IgG antibodies and the seroincidence of HSV-1 and HSV-2 infections in pregnant women attending the maternity clinic of the University Hospital Lausanne. STUDY DESIGN: Blood samples from 1030 women were taken at the usual pregnancy visit in the first trimester to assess the prevalence rate of IgG antibodies against HSV-1 and HSV-2 using a type-specific assay. A second blood sample was taken 6-8 weeks postpartum from returning women who were seronegative for HSV-2 or HSV-1 to assess the incidence of seroconversion (primary infection). RESULTS: The seroprevalence rates were 79.4% (95% CI: 76.9-81.9) for HSV-1 and 21.2% (18.7-23.7) for HSV-2 in women 14-46 years old. Type-specific serostatus patterns were as follows: 17.3% HSV-1/-2: +/+, 62.1% HSV-1/-2: +/-, 3.9% HSV-1/-2: -/+, 16.7% HSV-1/-2: -/-. Two hundred and sixty five women (59 of the 212 seronegative for HSV-1 (27.8%) and 265 of the 812 seronegative for HSV-2 (32.6%)) returned to the outpatient clinic for the post-delivery check and a second blood sample was obtained. One HSV-1 seroconversion was detected (HSV-1 seroconversion rate 2.4%/100 patient × year (95% CI: 0.06-13.4)) in a patient who had symptoms compatible with primary genital herpes. No HSV-2 seroconversion was detected (HSV-2 seroconversion rate: 0/100 patient × year (97.5% one-sided CI: 0-2)). CONCLUSION: Compared to a previous population-based study, our study results suggest a rise in the prevalence of HSV-2 among pregnant women in Switzerland. The low incidence of seroconversion detected during pregnancy is consistent with the very low reported incidence of neonatal herpes in Switzerland. CONDENSATION: This study in a public hospital in Western Switzerland suggests an increasing prevalence of HSV-2, but a low incidence of primary infections in women of childbearing age.

Cost-effectiveness of a new combined immunosuppressive and anti-infectious regimen in kidney transplantation.

OBJECTIVES: The aims of this study were to assess the 1-year cost-effectiveness of a new combined immunosuppressive and anti-infectious regimen in kidney transplantation to prevent both rejection and infectious complications. METHODS: Patients (pts) transplanted from January 2000 to March 2003 (Group A) and treated with a conventional protocol were compared with pts submitted to a combined regimen including universal cytomegalovirus (CMV) prophylaxis between April 2003 and July 2005 (Group B). Costs were computed from the hospital accounting system for hospital stays, and official tariffs for outpatient visits. Patients with incomplete costs data were excluded from analysis. RESULTS: Fifty-three patients were analyzed in Group A, and 60 in Group B. Baseline characteristics including CMV serostatus were not significantly different between the two groups. Over 12 months after transplantation, acute rejections decreased from 41.5 percent in Group A to 6.7 percent in Group B (p < .001), and CMV infections from 47 percent to 15 percent (p < .001). Overall, readmissions decreased from 68 percent to 55 percent (p = .160), and average hospital days from 28 +/- 19 to 20 +/- 11 days (p < .007). The average number of outpatient visits decreased from 49 +/- 10 to 39 +/- 8 (p < .001). Average 1-year immunosuppressive and CMV prophylaxis costs (per patient) increased from CHF20,402 +/- 7,273 to 27,375 +/- 6,063 (p < .001), graft rejection costs decreased from CHF4,595 +/- 10,182 to 650 +/- 3,167 (p = .005), CMV treatment costs from CHF2,270 +/- 6,161 to 101 +/- 326 (p = .008), and outpatient visits costs from CHF8,466 +/- 1'721 to 6,749 +/- 1,159 (p < .001). Altogether, 1-year treatment costs decreased from CHF39'957 +/- 16,573 to 36,204 +/- 6,901 (p = .115). CONCLUSIONS: The new combined regimen administered in Group B was significantly more effective, and its additional costs were more than offset by savings associated with complications avoidance.

Macrophage migration inhibitory factor reduces the growth of virulent Mycobacterium tuberculosis in human macrophages.

Macrophage migration inhibitory factor (MIF) is a key mediator of the innate immune system and plays a crucial role in the host response to bacterial infections. Its role in immunity to intracellular pathogens has not been well studied. Here, we show that MIF released by infected human macrophages inhibits the growth of virulent Mycobacterium tuberculosis.

HIV-1-infected patients with focal neurologic signs: diagnostic role of PCR for Toxoplasma gondii, Epstein-Barr virus, and JC virus.

OBJECTIVE: To evaluate nested PCR for Toxoplasma gondii (TOX), JC virus (JCV) and Epstein-Barr virus (EBV) for diagnosis of toxoplasmic encephalitis (TE), progressive multifocal leukencephalopathy (PML) and primary central nervous system lymphoma (PCL). METHODS: A prospective study encompassed 26 HIV-1-infected individuals presenting with focal neurologic signs and symptoms. Nested PCR was performed on both supernatants and pellets of centrifuged cerebrospinal fluid (CSF), on plasma and on white blood cells (WBCs). For a retrospective study, stored CSF supernatants were available from an additional 27 HIV-1-infected patients with TE, PML, and PCL. RESULTS: TE, PML or PCL was diagnosed in 13 of 26 patients in the prospective group. Plasma and WBC analysis by PCR was not informative except in one case of TE. TOX and JCV were detected by PCR in the CSF pellets of four of five patients with TE, and of four of five patients with PML, respectively, but in no other cases. EBV was detected not only in three of three cases of PCL, but also in six patients suffering from other conditions. PCR on the CSF supernatants was less sensitive for all three etiologies. These results correlated with those of the retrospective PCR analysis, for which only stored CSF supernatants were available, revealing sensitivities of 33%, 50% and 66% for TE, PML and PCL, respectively, but specificities of 100%. CONCLUSIONS: In the clinical routine, TOX and JCV PCR on centrifuged CSF pellets can be recommended to obtain an early diagnosis of TE and PML. Under these conditions, EBV PCR helps to exclude PCL as a cause of FBLs, as it is highly sensitive, but not specific, for PCL in HIV-1-infected individuals.