[Quantitative antibody analysis: use for the diagnosis of hepatitis C virus chronic infection]. / Analyse quantitative des anticorps dirigés contre le virus de l'hépatite C (VHC): application au diagnostic d'infection chronique par le VHC.

Hepatitis C virus (HCV) infection has been estimated in 600,000 subjects in France, with about 80 % of chronic infection. In the latter, anti-HCV antibodies and viral RNA are found together in patients blood. Today, only the use of polymerase chain reaction (PCR) technology allows the diagnosis of HCV chronic infection, confirmed by a positive PCR. However, PCR is a laborious and cost effective method. The aim of this study was to distinguish HCV chronic infection to past-infection or false reactivity only using the serology testing. Therefore, we looked for a correlation between the results of PCR, using the HCV Cobas Amplicor 2.0 assay, and the level of anti-HCV antibodies, assessed by the AxSYM HCV v.3.0 and expressed in signal/cutoff (s/co) ratio. We found using a panel of 200 sera issued from 181 patients, a significant variation of s/co ratios between PCR positive and negative patients (respectively, 87.76 +/- 27.18 vs 10.13 +/- 13.68 s/co, p < 0.0001), only in non treated or previously treated patients, non HIV coinfected, non renal transplanted or haemodialysis patients. An anti-HCV cutoff value at 34 s/co allows a predictive PCR results with 100 % sensitivity and 93.3 % specificity. Thus, for patients having a s/co equal or over 34, a positive PCR was found in 98.1 % of cases, allowing the diagnosis of HCV chronic infection (positive predictive value). Conversely, in patients with less than 34, HCV chronic infection can be excluded in 100 % of cases (negative predictive value). In conclusion, in most cases, the use of anti-HCV quantitative analysis in the AxSYM HCV v.3.0 assay could avoid PCR testing and facilitate the diagnosis of HCV chronic infection.

[Antibody avidity: use for the diagnosis of HIV early infection]. / Avidité des anticorps: application au diagnostic d'infection récente à VIH1.

Determination of IgG avidity is useful to distinguish primary infection from reactivation or reinfection in viral, parasitic or bacterial infections. For diagnosis of HIV type 1 primary infection, the detection of IgM antibodies is often useless since they are also found in chronic infection. The usual serology (Elisa, western-blot, p24 antigen) may present no interest if done too late (more than 2 or 3 months after infection). Therefore, we have developed a test to determine the avidity of anti-HIV1 antibodies, using 1 M guanidine as denaturing agent. We have adapted the measurement of avidity to the Axsym automatic system for a routine use. Indeed, since requests for avidity determinations are sporadic, the use of microplates is not convenient. Using this assay, we found a low avidity (less than 50%) in immunocompetent and recent infected patients (less than 6 months), compared to old infected patients (more than 12 months) who had high avidity (80 to 100%). However, early treated patients (in the 6 months after contamination) had also low avidities but with a slower development of antibody maturation (8 to 27 months versus 2 to 8 months in non treated patients). To conclude, the determination of the anti-HIV1 avidity, according to the proper procedures explained here (notion of treatment and/or serious immunodepression), may help the physician to date the infection in each new infected patient who might benefit from an early treatment.

[Severe pneumonia with a pneumococcal aspect during an ornithosis outbreak]. / Pneumopathies sévères d'allure pneumonique, au cours d'une épidémie d'ornithose.

OBJECTIVES: To describe the clinical, radiological and biological features of Chlamydia psittaci pneumonia. METHODS: A pneumonia outbreak occurred in a healthy middle-aged population working in a poultry slaughterhouse. Systematic serology (2 samples at 5 weeks intervals) provided the diagnosis of Chlamydia psittaci pneumonia in 6 patients. Patient files were analyzed retrospectively. RESULTS: The clinical presentations in this series of pneumonia were particularly homogeneous with a pneumococcal profile in all 6 cases: sudden onset, temperature above 39 degrees C, lobar alveolar involvement, hypoxemia, hyperleukocytosis and liver dysfunction. One case of hallucinatory delirium was observed. The patients were given spiramycin (9 million units per day for 3 weeks) and all recovered rapidly with no complications. CONCLUSION: The unusual virulence of the Chlamydia psittaci and very important inoculum were probably involved in this outbreak because of the severity of the pulmonary features and the short exposure of some patients to the bacteria. These cases suggest that the prevention of ornithosis in poultry slaughterhouses should be reinforced.

Human cytomegalovirus DNA kinetics using a novel HCMV DNA quantitative assay in white blood cells of immunocompromised patients under Ganciclovir therapy.

The clearance of human cytomegalovirus (HCMV) was evaluated in infected patients under Ganciclovir (GCV) treatment, using a novel HCMV DNA quantitation assay (HCMV DNA hybrid capture system, Murex Diagnostics). Peripheral white blood cells (WBC) from whole blood specimens of seven AIDS patients, three kidney and two allogeneic bone marrow transplant (BMT) recipients suffering from HCMV disease, were assessed by this method. HCMV DNA 50 and 90% mean clearances were observed at 2.11 +/- 1.97 and 6.22 +/- 4.31 days, respectively, after initial GCV treatment. The viral DNA kinetics were correlated with positive and negative pp65 antigenaemia and viral blood culture. Two-fold higher clearances and initial DNA levels were observed in the AIDS group compared to the transplant group. Neither clinical nor virological relapses were observed under GCV treatment. HCMV DNA quantitation in WBC appears well adapted for a therapeutic follow up of patients with HCMV disease.

Novel DNA assay for cytomegalovirus detection: comparison with conventional culture and pp65 antigenemia assay.

We compared conventional cytomegalovirus (CMV) isolation, rapid viral culture, a CMV pp65 antigenemia assay, and a novel CMV DNA hybrid capture system (HCS). A total of 309 blood samples from individuals in different risk groups were assessed by at least two of the methods mentioned above. Leukocytes were recovered either after centrifugation in Leucosep tubes containing 1.080 Ficoll for pp65 assay or after simple differential lysis steps for DNA detection. HCS was based on DNA hybridization with a CMV RNA probe and its capture by antibodies to DNA-RNA hybrids. The CMV pp65 lower matrix protein was detected by fluorescence with c10-c11 monoclonal antibody in formalin-fixed leukocytes. Concordant results were observed for 92.9, 78.3, and 82.7% of the patients when comparing (i) viral culture and the pp65 antigenemia assay, (ii) viral culture and HCS, and (iii) the pp65 antigenemia assay and HCS, respectively. Discordant results were observed between a positive HCS result and negative culture and/or pp65 results. These results were associated with relatively low DNA levels (< 20 pg/10(6) cells) and positive viruria. In conclusion, the pp65 antigenemia assay is a rapid and reliable method of detecting CMV and is preferable to culture, but the Murex HCS appears to be more sensitive for CMV detection.

[Severe manifestations of non-poliomyelitic enterovirus infections in newborn infants]. / Manifestations sévères des infections à entérovirus non poliomyélitiques chez le nouveau-né.

The authors report eight cases of severe neonatal infections with Coxsackie and Echo virus. Meningo-encephalitis, aseptic meningitis, myocarditis and sepsis-like state were the most frequent presenting conditions. A high mortality rate was associated with meningo-encephalitis and low birth weight.

[Lyme disease, an infectious cause of facial paralysis. Apropos of a case]. / La maladie de Lyme, une cause infectieuse de paralysie faciale. A propos d'une observation.

A case of facial palsy first unilateral then bilateral, due to Lyme disease, is reported. This disease, transmitted by ticks, is caused by a spirochete (Borrelia burgdorferi) known as the etiologic agent since 1982.

[The role of cytomegalovirus in infantile deafness and deafness of unknown origin]. / Le Rôle du cytomégalovirus dans la surdité du nourrisson et sa place dans les surdités d'étiologie méconnue.

It is widely accepted that the cause of congenital deafness is genetic in one third of cases roughly, is due to acquired affections during pregnancy or delivery in another third and remains unknown in the last third. It is possible that the cytomegalovirus (CMV) plays an important role in the latter group. The CMV is thought to be involved in 10 to 30% of cases of auditory sequelae from fetal infection, either severe neonatal CMV-induced disease, which is rare, or the frequent subclinical infections affecting an average of 1% of newborn infants. The only certain way to determine the importance of the role of CMV in deafness of unknown etiology is large-scale neonatal biologic screening followed by long-term audiologic surveillance: currently available documented data suggest that this role is very important.

[Paget's bone disease. Preliminary serological study]. / Maladie osseuse de Paget. Etude sérologique préliminaire.

A serological study has been carried out in Paget's bone disease where the etiology still remains uncertain. Previous work on patients with the disease revealed specific osteoclast inclusions that could be linked to the presence of a virus of the paramyxovirus group. Conventional methods for exploring humoral immunity reveal no great differences in the concentration of antibodies against the various viral strains tested on sera from 46 patients with Paget's bone disease and from 46 paired controls. The viral origin of Paget's bone disease is reconsidered in the light of the results obtained. The eventuality of sub-threshold viral infection and the possible action of incomplete or defective virus leading to the chronic nature of the disease are discussed.

[Paget's bone disease. Preliminary serological study]. / Maladie osseuse de Paget. Etude sérologique préliminaire.

A serological study has been carried out in Paget's bone disease where the etiology still remains uncertain. Previous work on patients with the disease revealed specific osteoclast inclusions that could be linked to the presence of a virus of the paramyxovirus group. Conventional methods for exploring humoral immunity reveal no great differences in the concentration of antibodies against the various viral strains tested on sera from 46 patients with Paget's bone disease and from 46 paired controls. The viral origin of Paget's bone disease is reconsidered in the light of the results obtained. The eventuality of sub-threshold viral infection and the possible action of incomplete or defective virus leading to the chronic nature of the disease are discussed.

Viral antigens in osteoclasts from Paget's disease of bone.

Osteoclasts from patients with Paget's disease of bone contained viral antigenic material. Ultrastructural and immunological studies suggested that measles or measles-related virus was the agent involved.

[Demonstration by immunofluorescence and immunoperoxidase of an antigen of the measles type in the osteoclasts of Paget's disease of bone]. / Mise en évidence par immunofluorescence et immunopéroxydase d'un antigène de type rougeole dans les osstéoclastes de la maladie osseuse de Paget.

The intra nuclear and intra cytoplasmic inclusions described in osteoclasts in PAGET's bone disease are morphologically similar to those observed in subacute sclerosing panencephalitis. Immunological techniques using different specific immune sera demonstrate the presence of an antigenic structure of viral origin in osteoclasts in PAGET's bone disease. A measles or a measles like virus is most likely to be involved and may play a role in the etiology of the disease.

[Demonstration of measles virus antigens in osteoclasts in Paget's disease of bone]. / Mise en évidence d'antigènes viraux de rougeole dans les ostéoclastes de la maladie osseuse de Paget.

The first results of histo-immunological studies on biopsies in Paget's bone disease strongly favour the presence of antigenic material of viral origin in osteoclasts. Measles virus may play a role in the etiology of Paget's bone disease.

[Epidemic of listeriosis in Western France (1975--1976)]. / Epidémie de listériose dans l'Ouest de la France (1975--1976).

Cases of human listeriosis have recently increased in Western France (Maine-et-Loire and Mayenne); until 1974, there were only 15 documented cases yearly where as in 1975, there were 113 cases, and in 1976, 54 documented cases at the hospitals of Angers and Laval. Included amongst the clinical manifestations observed, were 126 cases of materno-fetal infections and 41 cases of either septicemia or meningo-encephalitis. The bacteriological study revealed a certain variability of biological characteristics examined, the overwhelming frequence of bacteria of the strain 4 b and the predictable sensitivity of this strain to antibiotics commonly employed in cases of listeriosis. The human cases were notably more frequent between January and June but their geographical distribution was not related to cases of either animal disease nor listeria that was isolated from corn silage. In this report, we propose an etio-pathological explanation for this epidemic.

[Epidemiological study of antibiotic resistance of Escherichia coli strains isolated during one year at the regional hospital center of Angers. Trial of a statistical method]. / Etude épidémiologique de la résistance aux antibiotiques des souches d'Escherichia coli isolées durant un an au Centre Hospitalier régional d'Angers. Essai d'une méthodologie statistique

A study of 1956 strains of Escherichia coli isolated at the Angers Regional Hospital Center during the year 1972, was used for the development of a statistical method of study of epidemiology of antibiotic resistance.

[Serodiagnosis of human brucellosis]. / Sérodiagnostic de la brucellose humaine

On the basis of the serological study of 1000 sera obtained from patients suspected of suffering from brucellosis, the authors emphasis the theoretical data which confer upon this complement fixation reaction a greater reliability than the agglutination reaction. Using an appropriate antigenic preparation, the complement fixation reaction indeed proves to be of greater interest than the classical Wright sero-agglutination test in the diagnosis of brucellosis.