Anders Sönnerborg

HIV in pregnant women and their offspring: evidence for late transmission

To assess the role of maternal viraemia in vertical transmission of HIV and the extent to which viraemia occurs during the various stages of pregnancy, we have attempted to detect human immunodeficiency virus (HIV) in 44 pregnant HIV-1 infected women during 47 pregnancies (30 continued, 17 aborted) and in 30 children and 12 fetuses. Infectious HIV was detected at some time during pregnancy in 59% of women from plasma and in 83% from either peripheral blood mononuclear cells or plasma. HIV was not isolated from any of the newborn babies (0/27) at birth. The mothers had a significantly higher frequency of viraemia during pregnancy than their children had by 6 months of age (p = 0.002); by this time HIV was recovered from 5 (26%) of 19 infants. HIV was not detected by virus isolation, in-situ hybridisation, or polymerase chain reaction (PCR) in 10 fetuses; the other 2 fetuses were positive either by in-situ hybridisation or by PCR but neither result could be confirmed in a second organ or by the other methods of detection. The findings show that there is no consistent spread of HIV across the placenta during maternal viraemia, and indicate that in most cases transmission occurs close to or at delivery.

Antigen detection in primary HIV infection.

Serial blood samples were obtained from 21 homosexuals who had developed symptomatic primary infection with human immunodeficiency virus (HIV) after a median incubation time of 14 days. During the first two weeks after the onset of illness HIV antigen (p24) was detected in the blood by enzyme linked immunosorbent assay (ELISA). During the second and third weeks after the onset of illness p24 antibody was detected by Western blot assay and antigen concentrations rapidly decreased to undetectable values. Dissociation of antigen-antibody complexes showed complexed antigen during the phase of declining concentrations of free antigen. Neither free nor complexed antigen was detected in any serum samples for several months thereafter, which suggested that failure to detect HIV antigen reflected low or absent synthesis of viral protein rather than masking of antigen by antibodies. Reappearance of HIV antigen with a fall in p24 antibody concentration was observed in a few patients six months or more after the onset of disease. The combined use of antigen and antibody assays made it possible to obtain evidence of infection with HIV in all of the 95 serum samples tested, illustrating the usefulness of these assays for diagnosing infection with HIV in its early stages.

Increased production of malondialdehyde in patients with HIV infection

The mean plasma content of malondialdehyde (MDA) in 30 patients in different stages of HIV infection was found to be about 30% higher than that in controls. The phenomenon was not correlated to the degree of immunodeficiency and was noted early in the course of the disease. This indicates a higher degree of basal lipid peroxidation, which might contribute to the tissue damage seen in these patients. A new reverse phase liquid chromatography method was used for quantitative measurements of MDA in plasma after reaction of this compound with thiobarbituric acid.

Serum Hepatitis C Virus RNA Levels in Chronic Hepatitis C-Importance for outcome of interferon alfa-2b treatment

Sera from 39 out of 40 patients with chronic hepatitis C virus (HCV) infection who had been treated for 60 weeks with interferon alfa-2b proved initially HCV RNA positive by reversed transcriptase polymerase chain reaction (PCR). These patients were analysed for genotype and quantitatively for HCV RNA levels prior to treatment by using a competitive PCR method with colorimetric detection of the amplified products. HCV RNA levels were correlated to outcome of treatment, mode of acquisition, histology and HCV genotype. The median pretreatment HCV RNA level in sustained responders (n = 15) with eradication of the viremia and normalization of serum ALT levels lasting 24 weeks post treatment was significantly lower than that in the combined group of non-sustained responders (n = 9) and non-responders (n = 15), 2.52 x 10(5) vs 8.90 x 10(5) genome equivalents per ml serum, p < 0.0125, respectively. 10 out of 17 patients with HCV RNA levels lower than the median level (5.64 x 10(5) genome equivalents per ml serum) had a sustained response to interferon treatment versus only 5/22 with levels equal to or higher than the median level, p = 0.04. No significant pretreatment differences in median HCV RNA levels according to mode of acquisition, genotype, or liver histology prior to treatment were seen. It is concluded that a low pretreatment HCV RNA level seems to be indicative of a sustained response to interferon alfa-2b treatment, whereas a high level seems to be indicative of a non-sustained or non-response. In the individual patient, however, the levels varied widely irrespective of response category.

Sequence analysis of selected regions of the env (V3 loop and gp41) and gag (p7) reading frames of Ethiopian human immunodeficiency virus type 1 strains.

SummaryAmplified polymerase chain reaction (PCR) products, corresponding to the V3 loop and gp 41 of theenv, and p 7 of thegag region, from proviral DNA of several Ethiopian and Swedish HIV-1 strains were sequenced. Of the six amino acids (GPGRAF) that constitute the principal neutralizing determinant (PND) within the V 3 loop, the Ethiopian isolates all showed two amino acid changes (GPGQTF). Four to five other substitutions were found in the amino acids flanking the PND. Substitution of alanine (A) for threonine (T) should result in a change in the predicted secondary structure, i.e., disappearance of a coil structure. Percentage similarity data on a stretch of 22 amino acids within the V 3 loop showed a concordance of the Ethiopian HIV-1 isolates with the sequences of published macrophage-T-cell tropic HIV isolates. Additionally derived protein sequences in two other regions showed two common substitutions in p 7 and one to two substitutions in gp 41 compared to a recent consensus sequence. These changes are hitherto unique for the Ethiopian strains, and suggest the presence of a clustering of a divergent HIV-1 strain in Addis Ababa, Ethiopia.

HIV-1 in Ethiopia : phylogenetic divergence from other HIV-1 strains

Phylogenetic tree analysis was performed on selected polymerase chain reaction (PCR)-amplified and sequenced regions of the gag and env reading frames of several Ethiopian and Swedish human immunodeficiency virus type 1 (HIV-1) strains. These regions are considered to be conserved parts of the HIV-1 genome and correspond to the p7 of the core (gag) and part of the carboxy terminal of the gp41 protein of env respectively. Comparisons were made with all available HIV-1 sequences.The tree analysis showed that gag sequences from nine and env sequences from four Ethiopian strains all grouped together in separate branches distinct from all other sequenced European, North American, and African HIV-1 isolates. Thus, the Ethiopian strains seem to represent a highly divergent group of HIV-1, which might have developed during a relatively early stage of HIV-1 evolution.

Hepatitis C Virus Replication in Liver and Peripheral Blood Mononuclear Cells of Interferon- α-Treated and Untreated Patients with Chronic Hepatitis C

Yun ZB, Sonnerborg A, Weiland O. Hepatitis C virus replication in liver and peripheral blood mononuclear cells of interferon-α-treated and untreated patients with chronic hepatitis C. Scand J Gastroenterol 1994;29:82-86.Serum, liver tissue, and peripheral blood mononuclear cells (PBMC) were obtained from 72 patients with chronic hepatitis C, 19 of whom had received interferon-a (IFN-α) treatment. Hepatitis C virus (HCV) RNA was detected by polymerase chain reaction in the serum and liver of all patients with relapse after treatment and in 51 of 53 (96%) sera, 28 of 29 (97%) livers, and all of 13 (100%) PBMC from untreated patients but not in 3 patients with completely sustained responses. Minus-stranded HCV RNA was found in 5 of 14 (35%) sera, 16 of 17 (94%) livers, and 7 of 13 (53%) PBMC from untreated patients. The results indicate that HCV RNA is present not only in serum and liver but also in PBMC from the vast majority of untreated anti-HCV-seropositive patients and also in patients who respond to IF...

The neurotoxin-like sequence of human immunodeficiency virus GP120: A comparison of sequence data from patients with and without neurological symptoms

A region of the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein gp120 has been claimed previously to be homologous to parts of snake venom neurotoxins and rabies virus glycoprotein (“the neurotoxic loop”). We have determined DNA sequences directly from a polymerase chain reaction amplified fragment corresponding to this region of HIV-1 gp120 and have translated these to protein sequences. This was performed with the prototype HIVSF2 isolate and several Swedish HIV-1 strains, which were precultivated from blood cells or cerebrospinal fluid (CSF) or were directly obtained from CSF cells of patients with and without neurological symptoms. The results show that there are sequence similarities between a short segment of gp120 of clinical HIV-1 strains and the neurotoxic loop. The strains of patients with neurological symptoms did not, however, show a genetic shift of their sequences towards a greater similarity to the sequences of snake venom neurotoxins and rabies virus glycoprotein as compared to the strains of asymptomatic individuals.

Variability of the E2/NS1 Region of Swedish Hepatitis C Virus Strains and Its Correlation to Genotypes

Serum RNA was extracted from 5 Swedish patients infected with hepatitis C virus (HCV). The N-terminal part of the genomic region coding for the gp70 (E2/NS1), including the hypervariable domain of the E2 protein, was reverse transcribed and amplified by the polymerase chain reaction (PCR) using biotinylated primers. The amplicon was immobilized on magnetic polystyrene beads coated with streptavidine. Solid-state sequencing was carried out on the bound single-stranded DNA, after denaturation. The results of phylogenetic sequence analysis and calculated ratios of transition and transversion mutations showed that 4 of the strains clustered together with the USA prototype strains HCV-1 and HCV-H (genotype I), while 1 strain was close to the Japanese isolate HCV-J, and particularly to isolate HCV-BK (genotype II). Possible antigenic epitopes in the Swedish strains were mapped in the HVR region.