1,721,073 research outputs found
The replication cycle of Chlamydia trachomatis and Chlamydia psittaci: ultrastructural analysis.
Laboratory signs of acute or recent cytomegalovirus infection are common in cirrhosis of the liver
Human cytomegalovirus (CMV) is an ubiquitous pathogen that can cause severe and often fatal infections in immunocompromised patients. Patients with cirrhosis often show various degrees of impaired cellular immunity that could lead to acute CMV reactivation. The aim of the present study was to determine whether laboratory findings of active CMV infections are common in patients with cirrhosis. Fifty-five patients with cirrhosis were studied for acute CMV infection by virological (antigenemia and quantitative polymerase chain reaction in polymorphonuclear leukocytes) and serological (detection of anti-CMV IgM by immunoblot) methods. The same tests were carried out on 50 blood donors and on 20 chronic hepatitis patients, considered as control populations. Acute or recent CMV infection had occurred in 31 (56%) of 55 patients with cirrhosis, whereas only 1 out of 20 (5%) patients with chronic non-cirrhotic liver disease and none of the 50 blood donors had laboratory signs of active CMV infection. The difference between patients with cirrhosis and the control groups was significant (P < 0.001, χ2test). CMV in patients with cirrhosis was not related to age, gender, hepatitis C virus infection or hepatocellular carcinoma. There was no significant correlation between impairment of liver function and the presence of active CMV infection. Patients with cirrhosis should be considered at risk for CMV infection, that seems to be mild and asymptomatic. (C) 2000 Wiley-Liss, Inc
ANTIBODY RESPONSE TO INDIVIDUAL CYTOMEGALOVIRUS STRUCTURAL PROTEINS IN DIFFERENT GROUPS OF SUBJECTS
Prokaryotic expression of human cytomegalovirus pUS22 and its reactivity with human antibody
This work demonstrates that antibodies to the product of the recombinant pUS22 of human cytomegalovirus (HCMV) are present in human sera during natural infection. US22 gene product has been identified as a member of the US22 family which may be secreted from infected cells. It is an early protein of 593 amino acids, 76 Kd in molecular weight. US22 seems to be an antigen which stimulates a good IgG response. In fact specific IgGs were found in approximately 40% of the CMV positive sera irrespective of their anti-CMV IgG titer. Specific IgM antibodies to pUS22 were observed exclusively during primary infection and in the sera with a high anti-CMV IgM titer. pUS22 could be considered for inclusion in a cocktail of CMV recombinant proteins to determine seropositivity to CMV and also to diagnose an active CMV infection
Anticytomegalovirus (Anti-CMV) immunoglobulin G avidity in identification of pregnant women at risk of transmitting congenital CMV infection
In this work, we show that the determination of the anticytomegalovirus antibody avidity carried out before week 18 of gestation is a helpful tool to identify women for enrollment in prenatal diagnosis. This procedure can identify all pregnant women who will give birth to an infected newborn
Cytomegalovirus infection in pregnancy: A still complicated diagnostic problem
The diagnostic problems linked to human cytomegalovirus (HCMV) in pregnancy are many and not all have been fully defined. In long-term seropositive women there is a tacit agreement that no laboratory testing for HCMV should be carried out. In seronegative women a test for HCMV-specific IgG should be performed at least twice during the first 4 months of pregnancy, and if the seronegativity persists, further follow-up might be stopped. On the other hand, if a seropositivity appears the diagnosis of a primary HCMV infection is established and prenatal diagnosis should be offered to the mother. Finally, in the case of a pregnant woman with unknown serological status, the diagnosis of HCMV infection is a complex problem and several different questions need to be addressed. In our opinion they should be screened with a reliable IgM test (confirmed by blot if necessary) followed, in the case of positivity, by an avidity assay. Pregnant women undergoing a primary HCMV infection should be encouraged to seek prenatal diagnosis to be performed by PCR and virus isolation from amniotic fluid at the 21st to 23rd week of gestation
Congenital cytomegalovirus infection in twin pregnancies: viral load in the amniotic fluid and pregnancy outcome
Human cytomegalovirus (CMV) is the most common cause of viral intrauterine infection and fetal damage largely attributable to maternal primary infection. Most cases of congenital CMV infection in twins reported in the literature involved only 1 twin. We assessed the validity of polymerase chain reaction (PCR) and quantitative PCR on amniotic fluid (AF), at 21 to 22 weeks' gestation and at least 6 to 8 weeks after seroconversion, to predict the outcome of newborns in twin pregnancies. Two pregnant women with twin pregnancies and 1 woman with a triple pregnancy with primary CMV infection defined by the presence of immunoglobulin (Ig) M and low IgG avidity and/or by the presence of clinical symptoms and abnormal liver enzyme values were evaluated. CMV infection was found in 6 fetuses/newborns, 3 of whom were symptomatic. In the first twin pregnancy with diamniotic-dichorionic separate placentas, CMV symptomatic infection of the female twin was demonstrated by positive virus isolation and high viral load in AF. The male fetus was not infected as demonstrated by negative CMV culture and DNA detection in AF. In the triple pregnancy, the woman had a placenta with 2 monozygotic twins (females) and a separate placenta with a heterozygotic twin (male). The quantitative PCR results were 103 genome equivalents (GE)/mL of females AF and 1.9x10(5) GE/mL of male AF. Both female twins were asymptomatic at birth, whereas the male presented petechiae, thrombocytopenia, and cerebral ventriculomegaly. In the last twin pregnancy with fused dichorionic placentas, congenital CMV infection of both twins was diagnosed at birth in contrast with prenatal diagnosis. At time of amniocentesis, the left side twin was not infected as shown by negative results of CMV culture and DNA detection in the AF. CMV infection of the right side twin was demonstrated by positive CMV DNA detection with a CMV DNA load of 4.9x10(4) GE/mL and positive virus isolation in the AF. The morphologic and histologic examinations of the placentas strongly supported a prenatal horizontal acquisition of CMV infection. These twin pregnancies showed a marked difference in the quantity of virus load documented by the prenatal diagnosis suggesting that twin fetuses may react differently to primary maternal infection despite being exposed to the same maternal influences. A high viral load is correlated with congenital CMV infections symptomatic at birth. In such cases, with fetal infection of only 1 twin (at amniocentesis) and fusion of placentas, fetal outcome of both twins needs to be evaluated for the possibility of viral transfer from one fetus to the other
A novel Western blot test containing both viral and recombinant proteins for anticytomegalovirus immunoglobulin M detection.
We devised a novel Western blot (WB) test for anti-human cytomegalovirus (HCMV) immunoglobulin M (IgM) detection which contains viral structural polypeptides, significant portions of recombinant p150 (ppUL32), and a significant portion of the must immunogenic nonstructural protein p52 (ppUL44). This new test was evaluated in latently infected blood donors, pregnant women, and transplant recipients with ongoing HCMV infection and shown to be more sensitive and specific than traditional WB and conventional enzyme immunoassay for the detection of HCMV-specific IgM
Prenatal diagnosis of symptomatic congenital cytomegalovirus infection
OBJECTIVE: The aim of this study was to evaluate whether the amniotic viral load of mothers with primary cytomegalovirus infection correlate with fetal or neonatal outcomes.
STUDY DESIGN: Sixty-eight of 138 pregnant women with primary infection defined by immunoglobulin G seroconversion or the presence of immunoglobulin M with low immunoglobulin G avidity accepted amniocentesis. Polymerase chain reaction and quantitative polymerase chain reaction were used to detect amniotic fluid cytomegalovirus. Cytomegalovirus infection in neonates was determined by means of urinary viral isolation during the first week after birth or the histologic examination of tissue from aborted fetuses.
RESULTS: Cytomegalovirus infection was found in 16 fetuses and neonates (23%), 5 of whom had symptoms. Quantitative polymerase chain reaction showed that the presence of greater than or equal to 10(3) genome equivalents predicted mother-child infection with 100% probability; greater than or equal to 10(5) genome equivalents predicted the development of a symptomatic infection.
CONCLUSION: Fewer than expected cytomegalovirus-infected fetuses are at risk for development of cytomegaloviral disease, and this fact may be useful in counseling pregnant women with primary cytomegalovirus infection
Prenatal indicators of congenital cytomegalovirus infection
Objective: To assess the validity of a diagnostic protocol designed to predict the outcome of newborns of mothers suspected to have primary cytomegalovirus (CMV) infection during the first 4 months of pregnancy.
Study design: Anti-CMV immunoglobulin (Ig) M detection by enzyme immunoassay and immunoblot together with the determination of anti-CMV IgG avidity allowed us to classify 456 women as (1) uninfected, (2) undergoing either a primary or a recurrent infection, or (3) having an undefined serologic condition. Prenatal diagnosis was carried out at 21 to 23 weeks' gestation for women. The presence of the virus in the amniotic fluid was determined by culture, polymerase chain reaction, and quantitative polymerase chain reaction, Macroscopic and histologic examinations were undertaken on tissue from aborted fetuses, whereas for newborns culture was performed on urine sampled during the first week of life.
Results: Congenital infections were found exclusively among women undergoing a primary infection. The quantitative determination of CMV DNA in the amniotic fluid of at least 10(3) genome equivalents gave a 100% certainty of detecting an infected fetus. Higher viral loads were associated with fetuses or newborns with symptoms.
Conclusions: IgM tests and the IgG avidity determination can identify all women at risk of transmitting CMV Furthermore, a high CMV DNA load in amniotic fluid could be an indicator of symptomatic congenital infection at a relatively early stage of pregnancy
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