[Mechanisms of imiquimod indirect antiviral activity]. / Mécanismes de l'activité antivirale indirecte de l'imiquimod.

The potential role of an immune response in HPV-related anogenital disorders had already been anticipated by clinicians. Indeed the lesions efflorescence and the relapsing HPV infection in HIV positive patients as well as the lack of recurrence in patients with spontaneous cure, provided relevant clues for a likely immune mechanism. At present time, the role of the immune system in the development of HPV-related anogenital disorders is well established : HPV induce a humoral and cell mediated immune response. This response is mainly exerted towards infected cells; it is also exerted at the systemic level, through antibodies synthesis, but this pathway remains a secondary one. Due to the limits of the present therapies (either purely destructive and characterized by the rate of recurrences, or antiviral, but difficult to use), it was necessary to find a new treatment type which enhances the local immune response, results in the disappearance of lesions and allows for a decrease in the risk of recurrences. The original mechanism of action of the first cell-mediated immune response modifier: imiquimod, for local use (Aldara 5 % cream) is an answer to this need. The first positive results observed in vitro and in animals were confirmed in patients with HPV anogenital warts in a double blind placebo-controlled study: imiquimod inhibits HPV replication and results in the condyloma regression. Its action is based on the combined activation of the natural local immunity, by stimulating interferon alpha; and of the acquired immunity, by stimulating a T-cell mediated immune response. Thus imiquimod appears to be an original antiviral compound, because it does not act directly on the virus itself.

Human polyomavirus JC latency and reactivation status in blood of HIV-1-positive immunocompromised patients with and without progressive multifocal leukoencephalopathy.

BACKGROUND: Human polyomavirus JC (JCV) induces human progressive multifocal leukoencephalopathy (PML) in patients with AIDS. Peripheral blood mononuclear cells (PBMC) of HIV-1-positive immunocompetent and immunocompromised patients can harbour JCV genome, but their precise role in JCV latency or reactivation status before the onset of PML remains hypothetical. OBJECTIVES: To assess JCV latency or reactivation status in PBMC of HIV-1-positive immunocompromised patients without PML. DESIGN: A group of 82 HIV-1-positive immunocompromised patients who did not have PML were compared with 10 patients with AIDS and PML and with 69 HIV-1-positive immunocompetent patients without PML. METHODS: DNA and total RNA were extracted from PBMC. The presence of JCV DNA was demonstrated by a semi-nested polymerase chain reaction (PCR). By using primer pairs specific for an early gene,T, and a late gene, VP1, the expression of both early and late gene mRNA in PBMC could be identified using reverse transcriptase (RT) PCR. RESULTS: JCV DNA was detected by PCR in 17.4% of 69 HIV-1-positive immunocompetent patients, in 23.2% of 82 HIV-1-positive immunocompromised patients, and in 60% of 10 patients with AIDS and PML. No correlation could be drawn between the detection of JCV DNA in the PBMC and the clinical or biological status of the HIV-1-positive patients. By using RT-PCR procedures, no expression of JCV early and late mRNA in PBMC was found in any patients. CONCLUSIONS: JCV DNA is detectable in the PBMC of 20.5% of 151 HIV-1-infected patients independently of the CDC (Centers for Disease Control and Prevention) stages of the infection. Moreover, our results suggest that active replication of JCV in PBMC appears to be absent or at least a very rare event in HIV-1-positive immunocompromised patients with and without PML.

Hepatitis B circulating immune complexes. Characterization by radioimmunoprecipitation--PEG assay (RIPEGA).

Incidence of circulating immune complexes (IC) was investigated in carriers of hepatitis B antigen (HBAg) and/or anti-HB antibodies (anti-HBAb). Three methods were used: radiolabelled C1q binding test (C1qBT), complement fixation test (CFT), and optical density (OD) measurement after dissolution of 3% polyethylene glycol (PEG) precipitate of serum. A highly significant correlation was obtained between these three techniques. The level of IC was higher in carriers of HBAg without anti-HBAb, than in others. The characterization of HBAg and anti-HBAB in IC was carried out by a new procedure, the radioimmunoprecipitation-PEG assay (RIPEGA), This sensitive and reproducible test was performed by incubation of 125I-HBAg or 125I-HBAG with 3% precipitate of the carriers' sera. Separation of free from complexed 125I-HBAg or 125I-HBAb was achieved by PEG precipitation. A highly significant correlation was found between the levels of circulating IC evaluated by the C1q-BT and the quantities of HBAg or anti HBAb measured by RIPEGA. RIPEGA was used to quantify HBAg and anti-HBAb present in serum from HBAg and/or anti-HBAb carriers, confirmed by a radioimmunoassay. In preliminary results, RIPEGA was shown to be more sensitive than classical radioimmunoassay.

Plasma levels of sTNFR p75 and IL-8 in patients with HIV-1 infection.

We determined the degree of activation of the TNF alpha system and the levels of IL-8 in HIV-1 infection. TNF alpha is one of the most potent agents for the induction of IL-8. TNF alpha may be cleared rapidly from the circulation, however soluble tumor necrosis factor receptor (sTNFR) p75 which is more stable may reflect the degree of activation of the TNF alpha system. We measured concentrations of sTNFR p75 and IL-8 with immunoassays in the plasma of 99 HIV-1-infected patients at different stages of disease (Centers for Disease Control classification) and in 20 healthy control subjects. Plasma levels of sTNFR p75 were elevated in most of the asymptomatic seropositive patients without CD4+ T cell depletion (Stage IIA) and in most of patients of all clinical groups compared with controls. However, in the majority of those patients plasma levels of IL-8 were not higher than those of controls. Our results suggest that sTNFR p75 levels but not IL-8 levels in circulating blood are high in the course of HIV-1 infection.

Enhanced TNF alpha production by monocytic-like cells exposed to dengue virus antigens.

The studies indicating the importance of TNF alpha in dengue virus infection have led us to determine whether monocyte-like cells produce TNF alpha exposure after dengue virus. The supernatant fluids of mosquito cells (AP61) infected with dengue virus (DV) type 1 and DV type 3 were harvested 7 days post-infection and clarified. DV inactivation was performed in the presence of betapropiolactone that preserves antigenicity of viruses. We used the monocytic-like cell line THP-1 that is a model system of TNF alpha production. Polymyxin B (50 micrograms/ml) was added to block untoward effects resulting from possible LPS contamination of media or cultures. THP-1 cells were primed with a phorbol ester (PMA) for 24 h, then they were cultured for 4 and 24 h in the presence of inactivated culture supernatant of dengue infected AP61 cells or control preparations. The concentrations of TNF alpha in the culture supernatants were measured by using an immunoenzymatic assay. PMA-treated THP-1 cells rapidly secreted TNF alpha in response to inactivated culture supernatant of DV-infected cells. We found high levels of TNF alpha with cells exposed to DV1 and DV3 preparations compared with controls (mean values; 465 and 829 vs. 70 pg/ml, respectively, at 24 h post exposure, n = 4). We obtained a substantial inhibition of the enhancing activity of DV1 and DV3 infected supernatants in the presence of dengue hyperimmune mouse ascitic fluids. Our results demonstrate that exposure of monocytes/macrophages to DV particles or virus proteins derived from DV may be responsible for the enhanced production of TNF alpha in DV-infected patients.

Soluble tumor necrosis factor receptor type II (sTNFRII) in HIV-infected patients: relationship with the plasma level of HIV-1 RNA.

The value of soluble receptor for tumor necrosis factor type II (sTNFRII) as a strong and early predictor of HIV disease progression was suggested. Recently it has been reported that sTNFRII may provide an indication of the HIV load. In this work we focused on the relationship between sTNFRII and HIV burden in 95 HIV-1+ patients without AIDS grouped according to the 1993 classification of the CDC as group A, n = 55, and group B, n = 40. Compared with healthy controls, higher values of sTNFRII were obtained in all groups of HIV-1 infected patients (P < 0.001), but we found no inverse correlation between sTNFRII and CD4+ lymphocyte counts in CDC group A and B of the disease, and no correlation with log RNA copy number in patients with CD4 T-cell counts > 499/microl. A correlation was obtained between sTNFRII and the viral load in patients with CD4 T-cell counts ranging from 200 to 499/microl, but only in CDC group B patients (P < 0.01, n = 26). There was no correlation between the variations of sTNFRII and HIV-1 RNA levels in 19 CDC group A and 15 CDC group B clinically stable patients in the course of a short follow up. The plasma level of sTNFRII do not appear as a valuable surrogate marker of the plasma level of HIV-1 RNA in patients. Further investigations are needed to define the mechanism of the raised level of sTNFRII in HIV-1 infected patients.

Angiotensin-converting enzyme in human adult respiratory distress syndrome.

Angiotensin-converting enzyme (ACE) levels, complement activation, and intravascular coagulation were studied in 36 patients with adult respiratory distress syndrome (ARDS) (17 aseptic, 19 septic), in order to investigate the possible interrelations among ACE, immunologic data, and hematologic findings. The severity of respiratory impairment was assessed with measurements of mechanical and gas exchange functional qualities of the lung. Serial measurements of ACE could be done in 14 patients during an eight-day period. During the first 24 hours, ACE levels were always normal (38 percent) or decreased (62 percent). No difference could be found between patients with septic and aseptic ARDS. Complement activation occurred in 78 percent (28/36) and used, in most cases, the classic pathway with presence of circulating immune complexes. Criteria for intravascular coagulation were present in 58 percent (21/36). No relation between coagulation, complement, and ACE could be found except for the patients with a greater respiratory impairment, who had complement activation, intravascular coagulation, and significantly lower ACE levels. In all patients together, ACE levels had no diagnostic value for aseptic cause of ARDS and a poor prognostic value. Only intravascular coagulation was linked with a higher significant mortality and a greater functional impairment. Serial measurements showed a diphasic evolution of ACE levels, with a maximum decrease between the 72nd and 96th hours and a further normalization (seventh day). The persistence of low levels seemed to be associated with evolutive sepsis or secondary aggravation and fibrosis.

In HIV-1-infected patients, plasma levels of HIV-1 RNA are inversely correlated with IFN-alpha responsiveness of whole-blood cultures to sendai virus.

BACKGROUND: A diminished or totally blocked IFN-alpha production in cells from HIV-1-infected patients has been reported. OBJECTIVE: To investigate the relationship between the decreased in vitro production of IFN-alpha and the plasma level of HIV-1 RNA. STUDY DESIGN: Whole blood samples of 39 healthy subjects and 44 HIV-1-infected patients were incubated in the presence of Sendai virus for 24 h. IFN-alpha contained in supernatants was assayed by using an immunochemical method (DELFIA) and by using an antiviral assay. Plasma HIV-1 RNA was measured by the Amplicor HIV-1 monitor test. RESULTS: The levels of IFN-alpha obtained were significantly lower in cultures from HIV-1 infected patients than in control subjects (P<0.0001). The antiviral activity in supernatants of Sendai virus-activated whole-blood cultures, assayed by protection of MDBK cells against vesicular stomatitis virus (VSV), was significantly lower in cultures from HIV-1 infected patients than in corresponding controls (P<0.0001). IFN-alpha values determined by DELFIA and those determined by bioassay were significantly correlated. In vitro production of IFN-alpha by whole-blood cultures correlated well with the plasma levels of HIV-1 RNA (P<0.001). CONCLUSIONS: In HIV-infected patients an increased rate of HIV-1 replication is associated with reduced responsiveness to induction of IFN-alpha by indicator virus, suggesting that HIV-1 replication causes impaired production of IFN-alpha by blood cells or vice-versa.

Serum levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and interleukin-1 beta (IL-1 beta) in dengue-infected patients.

Sensitive immunoenzymatic assays were used to study the levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and IL-1 beta in sera from dengue-infected patients obtained during the 1989-1990 outbreak of dengue-3 in Tahiti, French Polynesia. The patients, both children (n = 47) and adults (n = 18), were clinically classified as having dengue hemorrhagic fever (DHF) and graded according to the severity of illness (grade I = fever, grade II = fever with spontaneous hemorrhagic manifestations, grade III = circulatory failure, grade IV = deep shock). The serum samples were obtained from day 1 to day 10 after the onset of the disease. High levels of TNF-alpha were observed in dengue-infected children of all severity grades. The highest values of TNF-alpha were found before day 6 after the onset of the infection, these values decreased from day 6 to day 10. The highest values were observed in sera from grade III and IV patients. High values of IL-6 were observed in serum samples of grade I and II patients on day 1, which decreased on day 4, and by day 5 were similar to those obtained from 25 control children. In grade III and IV patients, the highest values of IL-6 were observed from day 3 to day 5 after the onset of infection; after day 5, these values were very low.(ABSTRACT TRUNCATED AT 250 WORDS)

Rapid detection of enterovirus in clinical specimens using PCR and microwell capture hybridization assay.

A rapid detection method of enteroviral RNA in clinical samples using PCR and a microwell capture hybridization assay is described. PCR products were labelled directly by digoxigenin-dUTP during the amplification step. The labelled amplicons were hybridized with a biotinylated oligo-probe and captured on commercially available test microwells coated with streptavidin. The hybridized amplicons labelled with digoxigenin were detected using anti-digoxigenin Fab fragments conjugated to peroxidase and colorimetric reaction automatically measured. This method detected as few as 0.01 PFU/100 microl of biological sample with a result obtained within 8 h. Using this method, we were able to detect enteroviral RNA in 23 of 35 clinical specimens from 16 of 17 patients with suspected acute or chronic enteroviral infection. The samples included cerebrospinal fluid, broncho-pulmonary lavage, pericardial effusion, throat swabs, stools, sera, muscular and myocardial biopsies. In contrast, virus was isolated in cell culture in only 8 of 28 clinical specimens from 6 of the 17 patients. This easy-to-perform assay has useful potential in the rapid detection of enterovirus in acute or chronic infection. This methodology could be used for a rapid qualitative detection of other RNA viruses.

Combination of whole blood culture and a rapid and sensitive cell assay for the determination of the cytopathogenicity of human immunodeficiency virus type-1 isolates.

It has been reported that in vitro biological properties of human immunodeficiency virus type 1 (HIV-1) isolates from patients are correlated with the prognosis of HIV-1 infection. A rapid assay was developed to study the phenotype of HIV-1 isolates. The P4 cell line is a HIV-1 infectible Hela CD4 cell carrying the bacterial LacZ gene under the control of the HIV-1 LTR (long terminal repeat). Conventional peripheral blood mononuclear cells (PBMCs) co-culture and heparinized whole blood (HWB) co-culture with normal PBMCs were used for HIV-1 isolated strains from 17 HIV-1-infected patients. The sensitivity of P4 cells was higher than that of MT-2 cells for detecting syncytia induced by HIV-1LAI (lymphadenopathy-associated virus). Like MT-2 cells, P4 cells enable the detection of syncytium inducing strains isolated in peripheral blood mononuclear cells (PBMCs) and HWB cultures. HIV-1 isolates with both culture methods from certain patients induced cytolysis without syncytium in P4 cells but had no cytopathic effect on MT-2 cells. The experiments are in favour of the direct effect of HIV-1 isolates of these patients in the lysis of P4 cells but its mechanism has not been elucidated. It was shown that the combination of whole blood culture for HIV-1 isolation and phenotype study with P4 cell assay is rapid and sensitive and could be used to monitor HIV-1-infected patients.

The MxA protein levels in whole blood lysates of patients with various viral infections.

Interferon alpha (IFNalpha), a type I interferon, can be considered as a viral infection marker because this cytokine is induced during many viral infections. However, it is quite difficult to detect IFNalpha in sera. Investigations are interested in various intra-cellular IFNalpha-induced proteins as viral infection markers. However the activity of these enzymes increased not only in response to type I IFNs but also to type II IFN. MxA protein can be detected in the cytoplasm of IFNalpha/beta-treated cells, whereas other cytokines, including IFNgamma, are poor inducers. Using an immunochemiluminescent assay, we studied MxA protein in whole blood of 34 patients with various viral infections. The whole blood was drawn into sterile vacuum tubes containing heparin or EDTA. MxA values were relatively similar in heparin-treated samples and EDTA-treated samples, with differences not exceeding 1 ng/ml. The levels of MxA protein were compared in whole blood obtained by using two different lysis procedures. A correlation was found between the MxA levels obtained by using procedure I and procedure II, but higher amounts of MxA protein were found with procedure II. The second procedure is rapid and more convenient than the other and it is carried out in one step which reduce technical problems. High levels of MxA protein were found in peripheral blood cells of patients with acute viral infections (Rotavirus, Adenovirus, RSV, CMV), but MxA protein was not elevated in bacterial infections. The MxA levels were also studied in peripheral blood of 32 HCV positive patients. MxA protein was not found in most of IFNalpha-untreated patients, even those with high viral load. In contrast, high levels of MxA protein were found in IFNalpha-treated patients. MxA quantitation can be considered as a specific marker of acute viral infections, and could be useful in the management of treatment with IFNalpha.

[CA 19-9 in early cancers of the bronchi. Comparison with the carcinoembryogenic antigen]. / Le CA 19-9 dans les cancers primitifs des bronches. Comparison avec l'antigène carcino-embryonnaire.

CA 19-9 (monosialoganglioside) isolated from adenocarcinomas of the gastrointestinal tract can be measured in biological fluids using a monoclonal antibody assay. A radioimmunometric assay kit produced by ORIS Industrie has been used to measure the serum level of CA 19-9 in lung cancer and the results have been compared to that of carcinoembryonic antigen. The combination of the 2 markers increase by 10% the number of subjects with a raised marker. There is no significant relationship between the levels of CA 19-9, the type of tumour or the tumour stage. The recognition of the sialic acid as an epitope by the monoclonal antibody appears to be responsible for the false positive results in non-malignant lung disease.

Procalcitonin as a marker of bacterial sepsis in patients infected with HIV-1.

Procalcitonin (ProCT) is a recently described marker of severe sepsis. It was decided to assess the value of proCT as a marker of secondary infection in patients infected with HIV-1. ProCT plasma levels were measured by immunoluminometric assay in a prospective study in 155 HIV-infected individuals: 102 asymptomatic and 53 with lever or suspected secondary infections. The baseline plasma level of ProCT was low (0.5 ng/ml +/- 0.37), even in the latest stages of the disease, and did not differ from the values of healthy subjects (0.54 ng/ml +/- 0.08). EDTA-treated whole blood was collected from patients before starting specific antimicrobial therapy. No elevation of ProCT level was detected in HIV-infected patients with evolving secondary infections including PCP (n = 4), cerebral toxoplasmosis (n = 4), viral infections (n = 9), mycobacterial infections (n = 5), localized bacterial (n = 12) and fungal infections (n = 4), malignancies (n = 3), and in various associated infectious and non-infectious febrile events (n = 13). All these plasma values were lower than 2.1 ng/ml. In contrast, high ProCT plasma levels were detected in one HIV-infected patient with a septicaemic Haemophilus influenzae infection (16.5 ng/ml) and another one with a septicaemic Pseudomonas aeruginosa infection (44.1 ng/ ml), ProCT values decreased rapidly under appropriate therapy. ProCT seems to be a specific marker of bacterial sepsis in HIV-infected patients, as no increase in other secondary infections could be detected in those patients. A rapid determination of ProCT level could be useful to confirm or refute bacterial sepsis for a better management of febrile HIV-infected patients.

Virucidal activity of pure singlet oxygen generated by thermolysis of a water-soluble naphthalene endoperoxide.

Using the water-soluble naphthalene carrier of singlet oxygen NDPO2, we have shown that pure singlet oxygen is able to inactivate enveloped viruses (human immunodeficiency virus type 1, herpes simplex virus type 1, cytomegalovirus, vesicular stomatitis virus), but has no effect on non-enveloped viruses (adenovirus and poliovirus 1). These results are related to the experiments on photoinactivation of viruses by hydrophobic photosensitizers (merocyanine 540, hypericin, phthalocyanines, hematoporphyrin and benzoporphyrin derivatives) and they strengthen the hypothesis that singlet oxygen plays a predominant role in this process.

[Effects of a high dose of vitamin A on experimental immunologic arthritis]. / Effets d'une dose élevée de vitamine A sur les arthrites immunitaires expérimentales.

Vitamin A, a good adjuvant to immunologic reactions, has in this aspect an interesting therapeutic effect, especially in immunotherapy. On the other hand, in diseases caused by circulating immunocomplexes or in auto-immune diseases, vitamin A can prolong the pathologic immunologic process. This experimental study shows that vitamin A in high doses has an adjuvant effect, that is aggravating considerably the immunologic arthritis induced in the Wistar rat.

[Anti-Coxsackie antibodies and congestive cardiomyopathies]. / Anticorps anti-Coxsackies et cardiomyopathies congestives.

During a 4-years period 122 patients admitted to the cardiologic hospital in Lille presented a significative positivity of serological reaction against Coxsackievirus B. Among these patients 19 suffered from acute pericarditis, 4 from cardiac arrhythmias, 3 from Bornholm syndrome and 14 from apparently primary congestive cardiomyopathy. In most of these 14 patients representing 18.4% of congestive cardiomyopathies investigated at the same time, hemodynamic studies and heart scanning with radioactive gallium were performed. 7 of these patients had a chronic (group A) and 7 an acute evolution (group B). In group A the scans were negative 4 times out of 5, whereas in group B they were positive in 5 out of 5 examinations. The control group including 3247 patients coming from the Institut Pasteur exhibited serological positivity in 4.6% of cases. Comparison of this group with that of cardiomyopathies shows a significant difference (p less than 0.001). The authors draw the attention to the frequency of positive serodiagnosis in congestive cardiomyopathy and stress the importance of gallium scintiscanning.

[Value of gene amplification of herpesviruses in the diagnosis and treatment of acute viral encephalitis]. / Valeur de l'amplification génique du virus herpétique dans le diagnostic et le traitement des encéphalites aiguës virales.

Positive diagnosis of Herpes simplex virus (HSV) encephalitis was rarely obtained in the past, when brain biopsy had been performed. Other tests (HSV antigen and HSV antibodies detection and interferon alpha measurement, in cerebrospinal fluid) failed to prove HSV infection. Polymerase chain reaction has been proposed for accurate and rapid diagnosis of HSV encephalitis. With 35 cycles of a DNA polymerase sequence duplication, sensitivity reaches 95% and specificity 100%. HSV PCR is a useful tool for the diagnosis of acute encephalitis. This should be available in many neurologic clinics. Therapeutic consequences include rapid disruption of aciclovir when clinical features, MRI study and negative PCR suggest non herpetic encephalitis.

[Hepatitis E virus]. / Le virus de l'hépatite E.

Hepatitis E, a faecal-oral waterborne acute viral hepatitis, occurs most frequently in epidemic outbreaks in developing countries. Hepatitis E virus (HEV) is spherical, nonenveloped and varied in size from 27 to 34 nm with a spiked surface. Experimental HEV infection in primates, molecular cloning involving cDNA libraries and recombinant protein technology indicate that the genome can be assigned to a 7.6 kb single stranded positive polyadenylated RNA. In a 5'NS-S poly A 3' molecular structure, three partially overlapping ORF have been identified. Two strains (Burma and Mexico) have been studied and although they related to caliciviruses, the genetic organization indicates that it represents different agents ranged in a new subgroup: the alpha-like viruses. HEV is an important cause of morbidity and mortality in developing countries in the 15 to 40 year age-group and although the mortality rate is low in the general population (0.5 to 3%), it averages 17 to 20% among third-trimester pregnant women. Several sporadic cases have been recently identified among children. The prevalence of anti-HEV antibodies in blood donors ranges from 2 to 3% in North Europe and USA and from 6.8% in Spain to 70% in Thailand. The average incubation period is 6 weeks. Chronic liver disease, persistent viraemia and oncogenicity have not been observed. HEV particles are identified in stool or bile by immune electron microscopy, capture immunoassay or RT-PCR.(ABSTRACT TRUNCATED AT 250 WORDS)

[Contribution of flow cytometry in virology]. / Les apports de la cytométrie en flux en virologie.

The development of commercial multichannel air-cooled laser flow cytometers which allow measurement of one or more characteristic parameters of particles or cells has been furthered due to advances in probes and fluorochromes. FITC-conjugated antibodies specific for selected cell surface molecules or for viral antigen expression in infected cells, fluorescein diacetate for labeling cells as a parameter of viability and propidium iodide as a DNA stain are generally used. Flow cytometric assays have been developed in virology to study the interactions of viruses with the immune system (Hantan Virus), to evaluate the diagnosis of secondary immunodeficiency syndromes (HIV), to analyze the protein and DNA content of virally infected cells during the cell cycle (SV40), to detect immediate early, early or late antigens in HCMV-infected cells, to assess the HCMV persistence in mononuclear cells, for use as a model for studying virus attachment to cellular receptors (EBV-echovirus), to screen and evaluate antiviral agents (Influenza C, HCMV, HSV, HIV) and to quantify antigens or antibodies simultaneously against various viruses (HCMV and HSV) or against different antigenic glycoproteins (HIV). This technology has thus become an important tool for the clinical virology and microbial serology laboratories.