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PubMed1993

Sequence variation within the human immunodeficiency virus V3 loop at seroconversion.

Analysis of the HIV-1 V3 quasispecies present in an individual at the time of seroconversion was carried out. The polymerase chain reaction (PCR) was used to amplify proviral HIV-1 DNA extracted from peripheral blood mononuclear cells from a patient who was viraemic (p24 = 15 pg/ml) and had an equivocal HIV-1 antibody status. The PCR products were cloned and the DNA sequence determined for 15 clones. These data showed that the V3 region contained only limited sequence heterogeneity with a major variant accounting for 66% of the protein quasispecies present. The protein sequence of the principal neutralising domain on all species contained the relatively rare GPGKTL motif rather than GPGRAF. The relevance of these data for early stages of HIV infection are discussed.

Amino Acid Sequence↗
PubMed1997

Primary infections with HIV-1 of women and their offspring in Rwanda: findings of heterogeneity at seroconversion, coinfection, and recombinants of HIV-1 subtypes A and C.

Variation in HIV-1 genomic RNA was studied in seroconversion samples from mother-child pairs from a Rwandan cohort. The mothers (n = 8) were heterosexually infected and their children (n = 6) were vertically infected by breast milk. Five of the children seroconverted within the same 3-month period as did their mothers. Highly homogeneous subtype A V3 and p17gag sequence populations were observed in three mother-child pairs, one of the two nontransmitting mothers, and one child (mean nucleotide distances 0 to 0.9%). Heterogeneous populations of subtype A V3 and p17gag sequences were found in one mother and a mother-child pair (1.4 to 2.8% for V3, 1.0 to 1.9% for p17). The second nontransmitting mother was infected with a heterogeneous AV1-V3/Cp17-p24 recombinant virus population (3. 8% for V3, 2.4% for p17). Finally, in one woman subtype C V3 sequences were observed, in addition to highly homogeneous subtype A V3 and p17gag sequence populations, also found in the child. Coexistence of subtype AV1-V3 and CV1-V3 env sequences in the mother was confirmed in a follow-up sample. The gag gene of both the maternal and the child's virus population represented an A/C recombinant sequence (Ap17/Cp24). An infection with subtype CV1-V3/p17-p24 was found upon testing of three additional participants of the mother-child cohort, indicating that subtype C is present in Rwanda. In conclusion, heterogeneity, coinfection, and intersubtype recombinants are not uncommon in primary HIV-1 infections in Rwanda.

Amino Acid Sequence↗
PubMed1992

Phlegmonous gastritis associated with HIV-1 seroconversion. Endoscopic and microscopic evolution.

A 40-year-old man presented with peritonitis. Diagnosis of phlegmonous gastritis was made by laparotomy. Conservative treatment combined with antibiotics was successful. Multiple endoscopies with biopsies illustrate the natural history of this disease. The patient developed HIV-1 seroconversion during hospital stay. Prompt diagnosis and treatment may improve the prognosis of this often lethal disease.

Abscess↗
PubMedDate not supplied

Immunoglobulin levels in haemophiliacs at HIV seroconversion and during follow up.

Immunoglobulins and aminotransferases were followed in 66 haemophilia patients and 13 von Willebrand patients over a six-year period. The results were correlated to HIV serology and lymphocyte subsets. Elevated IgG levels were found in 29/53 patients with haemophilia A, 2/13 with haemophilia B and in 0/13 with von Willebrand's disease. Elevated IgA and IgM levels were seen in 20% and 27% of the patients respectively, with a distribution similar to the elevated IgG levels, except that elevated IgA and IgM levels were also seen in 4/13 patients with von Willebrand's disease. Patients with HIV antibodies had significantly higher immunoglobulin levels than seronegative patients, and this elevation occurred in connection with seroconversion in the majority of the former. The IgG levels could not be correlated to the T4 cell count, but there has been a trend to less clinical symptoms related to HIV infection among those with stable IgG levels during the past few years. No correlation was found between elevated IgG levels and the aminotransferase levels, nor was any correlation found with the amount of blood coagulation factor concentrate given to the patients. The elevation of immunoglobulins observed in our haemophiliacs is multifactorial, but HIV infection is maybe the most important mechanism. The longitudinal IgG pattern may contribute to the prediction of the clinical outcome of this infection.

Adolescent↗
PubMed1988

Delayed seroconversion to HIV in a hemophiliac.

In a 14-year-old boy with severe hemophilia B, HIV seroconversion was observed about 2 years after substitution therapy had been changed to heat-treated PPSB concentrates. This shows that HIV-antibodies may appear in hemophiliacs after time periods longer than generally assumed.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Detection of human immunodeficiency virus type 1 by PCR before seroconversion in high-risk individuals who remain seronegative for prolonged periods.

HIV-1 seronegative patients at high risk for HIV infection were followed up. In 1990 PCR was positive for HIV DNA sequences in samples of 17 seronegative patients who continued to report for surveillance of HIV infection. There was clear evidence of seroconversion in four of these 17 seronegative patients, while in one patient an indeterminate result for HIV was repeatedly obtained in different samples. The other 12 patients continue to be seronegative without any evidence of HIV infection except the presence of provirus in peripheral blood mononuclear cells. It is important to apply the PCR technique together with tests to detect other virological and immunological markers, in order to identify seronegative carriers and thus avoid HIV transmission by them.

Adult↗
PubMed2002

Isolation of dengue virus serotype 1 from the blood of a Swiss traveler prior to seroconversion.

Dengue virus serotype 1 was isolated from the blood of a patient who had returned to Switzerland from Brazil with fever of unknown origin. After 2 days of culture on Aedes albopictus (C6/36) cell line, the dengue virus was identified as serotype 1 using a type-specific indirect immunofluorescence assay. The diagnosis was confirmed by seroconversion of anti-dengue virus-specific IgM and IgG antibodies and by amplification of a serotype 1-specific region of the dengue virus genome. This is the first description of dengue virus isolation from the blood of a traveler returning to Switzerland. We recommend detection of dengue viremia during the 1st week of illness, before serological tests usually yield conclusive results, as the most efficient means of early specific diagnosis.

Adult↗
PubMed1987

Spontaneous hepatitis B e antigen to antibody seroconversion and reversion in Chinese patients with chronic hepatitis B virus infection.

Five hundred twelve (373 men, 139 women) patients, aged 1-75 yr, with chronic hepatitis B virus infection seen during a 5-yr period were analyzed. Of these, 43.8% were hepatitis B e antigen (HBeAg)-positive, 49.2% were positive for hepatitis B e antibody, and 7% were negative for both HBeAg and hepatitis B e antibody at presentation. The cumulative probability of clearing HBeAg at the end of the first, second, and third years was 17%, 30%, and 34%, respectively. The probability of clearing HBeAg increased with the age of the patients. Reversion to HBeAg occurred in 7.8% of patients who were HBeAg-negative at presentation and 32.3% of HBeAg-positive patients who cleared HBeAg. In 70.6% of these patients, serum hepatitis B virus-deoxyribonucleic acid was persistently positive or became detectable at the time of HBeAg reversion. Most reversions occurred during the "e-window" phase. The reversions were transient in 31.8% of the cases. Recognition of the dynamics of these serologic changes is important in the evaluation of therapeutic regimens aimed at suppression of HBV replication and call for controlled trials with adequate duration of follow-up. Biochemical exacerbation of liver disease accompanied 38.7% of HBeAg to hepatitis B e antibody seroconversions and 34.8% of reversions. Such exacerbations may be mistaken for acute attacks of hepatitis B in patients not previously recognized to be hepatitis B surface antigen carriers and, in the absence of serial serologic data, are indistinguishable from superimposed non-A, non-B hepatitis.

Adolescent↗
PubMed1992

Is clearance of HIV-1 viraemia at seroconversion mediated by neutralising antibodies?

The mechanism of clearance of human immunodeficiency virus-1 (HIV-1) viraemia is not fully understood. In two patients with acute HIV-1 infection, initial high titres of free infectious virus in plasma declined rapidly to undetectable levels within 4-8 weeks, an event that was coincident with seroconversion. Neutralising antibodies directed against the first autologous isolates taken during the viraemic periods could not be detected in either patient around the time of disappearance of plasma virus. In the absence of functional neutralising antibody, it is unlikely that humoral factors are responsible for the suppression of primary viraemia in early HIV infection.

Adult↗
PubMed1992

Detection of false seroconversions in cytomegalovirus seronegative platelet donors by serial complement fixation or IgG-specific radioimmunosorbent tests.

A panel of 421 cytomegalovirus (CMV) seronegative-platelet donors was followed using complement-fixation (CFT) and IgG-specific radioimmunosorbent tests (RIST) to detect seroconversion. During 4623 person-months of observation 2452 serum specimens were tested, and the annual rate of seroreactivity detected by RIST was 56%. However, most of the positive RIST results were followed by negative results with later serum samples. CFT seroreactivity was a poor predictor of RIST seroreactivity. The high rate of transient seroreactivity detected by RIST may have reflected the lack of absolute specificity of the test. Alternatively, the results could illustrate the difficulty of determining whether an individual harbours latent CMV infection using antibody tests when some seronegative individuals appear to be latently infected. In the light of our observations recommendations for CMV antibody testing of blood donors are proposed.

Antibodies, Viral↗
PubMed1986

Poor seroconversion rate after hepatitis B vaccination in high-risk institutionalized mentally retarded patients.

We studied the rate of seroconversion to positivity for antibody to hepatitis B surface antigen (anti-HBs) after immunization with hepatitis B vaccine in a group of mentally retarded institutionalized patients. Eight hundred sixty-eight individuals were screened for seromarkers of hepatitis B infection (hepatitis B surface antigen and anti-HBs), and 287 seronegative patients were vaccinated with the recommended schedule of hepatitis B virus vaccine (20 micrograms IM at 0, 1, and 6 months). Overall, 59% of patients responded to vaccination with detectable anti-HBs. We found a high correlation of lack of response with both intragluteal injection and increasing age (p less than 0.0008), although the design of the study did not allow these factors to be analyzed separately. We conclude that buttock injection and advancing age may be risk factors for poor immunogenicity of the hepatitis B vaccine in mentally retarded populations.

Adult↗
PubMed1995

Vaccination against tick-borne encephalitis (TBE): influence of simultaneous application of TBE immunoglobulin on seroconversion and rate of adverse events.

One hundred and twenty-one of 128 enrolled healthy adult subjects were immunized against tick-borne encephalitis (TBE) either by TBE vaccine on days 0 and 28 (61 subjects) or simultaneously by TBE vaccine plus TBE immunoglobulin on day 0 plus TBE vaccine on day 28 (60 subjects). Formation of TBE antibodies were measured in ELISA on days 0, 28 and 56. On day 28 median TBE antibodies were twice as high in the vaccine group (2400) as in the vaccine plus immunoglobulin group (1200). Adverse events were more often observed after the first vaccination than after the second in both groups. In the vaccine group, adverse events after the first vaccine dose were remarkably more frequent (45% of these subjects reported 38 adverse events) than in the group who received vaccine plus immunoglobulin (25% of these subjects reported 18 adverse events). All types of adverse events (chills, flu-like symptoms, injection site pain) were reported less frequently in the vaccine plus immunoglobulin group. After the second vaccination the rate of adverse events was 7% in both groups. Seroconversion was achieved in all subjects on day 56 except one subject in the vaccine plus immunoglobulin group. Simultaneous application of TBE vaccine plus TBE immunoglobulin can be recommended for persons who need immediate protection plus active TBE vaccination.

Adult↗
PubMed1995

Ovine toxoplasmosis: seroconversion during pregnancy and lamb birth rate in Uruguayan sheep flocks.

Specific anti-Toxoplasma gondii antibodies were analyzed by latex agglutination during the 5 months of pregnancy in the serum of sheep from two flocks in the Uruguayan north-west: one flock (79 sheep) kept under an intensive management system and the other (494 sheep) kept under an extensive management system. Titers obtained using the latex test correlated with those obtained by indirect immunofluorescence. Pregnancy was confirmed by laparoscopy in all sheep from the smaller flock and by determination of serum progesterone levels in the seroconverted sheep from the larger flock. The percentage of sheep originally exhibiting significant serum levels of anti-T. gondii antibodies (13.9% in the smaller flock and 28.5% in the larger one) as well as the observed levels of seroconversion (22.8% and 7.7%, respectively), indicated a high prevalence of this infection in the north-west of Uruguay. In addition, birth rates of seroconverted sheep in the larger flock were significantly different from those of non-seroconverted animals. These results, although preliminary, suggest that Toxoplasma infection would produce considerable economic losses in extensive ovine production in Uruguay.

Animal Husbandry↗
PubMed1992

Incidence of HIV seroconversion in paediatric burn patients.

A retrospective review of paediatric patients treated for acute burn injuries and receiving blood/blood products between 1978 and 1985, identified 52 patients at risk for HIV infection. Over 50 per cent of the identified population had received 3 or more units of blood/blood products during their acute hospital stay. A total of 214 patients (36.8 per cent) have been tested for HIV seroconversions: five tested HIV positive by ELISA and four were confirmed by Western Blot, yielding a 1.9 per cent incidence. The four confirmed patients received 2-9 total body blood volume turnovers during their postburn period in hospital. At 4 years post-exposure, two patients show active disease, one is currently asymptomatic and one has died from AIDS-related sepsis.

Adolescent↗
PubMed1996

Acute HIV seroconversion illness presenting as African viral haemorrhagic fever.

BACKGROUND: Both human immunodeficiency virus type 1 (HIV-1) and African viral haemorrhagic fever (VHF) viruses cause similar symptoms in acutely infected individuals and must be included in the differential diagnosis in areas where HIV-1 and VHF viruses both occur. OBJECTIVES: To determine the cause of an acute illness in a patient at risk of exposure to both HIV-1 and African VHF viruses. RESULTS: Serological examination revealed the presence of high levels of the p24 core antigen of HIV-1 in the absence of antibodies to HIV-1 in a specimen collected during the acute stage of the infection. On follow-up, the antigen enzyme-linked immunosorbent assay (ELISA) became negative while the antibody ELISA and confirmatory Western blot for HIV-1 became positive. CONCLUSIONS: Acute HIV seroconversion illness may have protean manifestations and, in the more severe forms, may cause diagnostic dilemmas, particularly in regions where African VHFs occur.

Journal Article↗
PubMed2004

Visceral Kaposi's sarcoma associated with human herpesvirus 8 seroconversion in a heart transplant recipient.

A close association between human herpesvirus-8 (HHV-8) and Kaposi's sarcoma (KS) has been shown in transplant recipients, but donor-to-recipient transmission of HHV-8 is uncommon. Herein we report a case of a heart transplant recipient who had a fatal visceral KS in association with HHV-8 seroconversion at 18 months after transplantation with a donor having positive serology discovered after transplantation.

Adult↗