HIV evolution: CTL escape mutation and reversion after transmission.

Within-patient HIV evolution reflects the strong selection pressure driving viral escape from cytotoxic T-lymphocyte (CTL) recognition. Whether this intrapatient accumulation of escape mutations translates into HIV evolution at the population level has not been evaluated. We studied over 300 patients drawn from the B- and C-clade epidemics, focusing on human leukocyte antigen (HLA) alleles HLA-B57 and HLA-B5801, which are associated with long-term HIV control and are therefore likely to exert strong selection pressure on the virus. The CTL response dominating acute infection in HLA-B57/5801-positive subjects drove positive selection of an escape mutation that reverted to wild-type after transmission to HLA-B57/5801-negative individuals. A second escape mutation within the epitope, by contrast, was maintained after transmission. These data show that the process of accumulation of escape mutations within HIV is not inevitable. Complex epitope- and residue-specific selection forces, including CTL-mediated positive selection pressure and virus-mediated purifying selection, operate in tandem to shape HIV evolution at the population level.

Transmission of human immunodeficiency virus I drug resistance - a case report. What are the clinical implications?

The success of first-line antiretroviral therapy can be challenged by the acquisition of primary drug resistance. Here we report a case where baseline genotypic resistance testing detected resistance conferring nucleoside/nucleotide reverse transcriptase inhibitor (NRTI)-associated mutations, but no primary mutations for protease inhibitor (PI). Subsequent PI-based HAART with boosted saquinavir led to virological treatment success with persistently undetectable viral load. After treatment simplification from saquinavir to an atazanavir based PI-therapy and no change in backbone therapy rapid virological breakthrough occurred. Retrospective analysis displayed preexisting gag cleavage site mutations which may have reduced the genetic barrier in a clinical relevant manner in combination with the already existing NRTI resistance mutations. Alternatively, this effect could be explained with a different antiviral potency for the respective PIs used.

SEN Virus infection in HIV/HCV coinfected patients.

BACKGROUND: Chronic Hepatitis C Virus (HCV) infection is currently one of the most relevant coinfections in HIV positive patients. The influence of SEN Virus (SENV) on the outcome of HCV therapy in HIV/HCV coinfected patients who underwent combination therapy with pegylated interferon (PEG-IFN) and ribavirin is unclear. METHODS: SENV DNA was determined by polymerase chain reaction in 67 HIV/HCV coinfected patients, 77 HIV monoinfected patients, 95 treatment naive HCV monoinfetcted patients, and 122 healthy blood donors. Quantitative analysis was done for SENV H DNA. RESULTS: SENV DNA was detected in 8 of 67 (12%) HIV/HCV coinfected patients, in 9 of 77 (11.7%) HIV monoinfected patients, in 21 of 95 (22%) HCV monoinfected patients, and 12 of 122 (9.8%) healthy blood donors. HIV monoinfected patients showed the highest mean SENV H DNA level. The mean SENV H DNA was significantly lower in HIV/HCV coinfected patients compared to all other groups. The sustained virological response rates to combination therapy of HCV in HIV/HCV coinfected patients did not differ between patients with detectable SENV 5/8 (62.5%) and without SENV 28/59 (47.5%; p = 0.47). We found no significant difference in SENV H DNA pretreatment levels between nonresponders and responders to combination therapy (112 +/- 144 copies vs. 8 +/- 7 copies/ml; p = 0.27). CONCLUSION: Coinfection with HCV may reduce SENV H replication in HIV positive patients and results in significantly lower SENV H DNA levels in HIV/HCV coinfected patients. SENV infection has no influence on the outcome of HCV combination therapy in HIV/HCV coinfected patients.

De novo synthesis of purine nucleotides in human peripheral blood leukocytes. Excessive activity of the pathway in hypoxanthine-guanine phosphoribosyltransferase deficiency.

Human peripheral blood leukocytes were studied for the presence and the regulatory properties of the pathway of de novo synthesis of purine nucleotides. The cells were found to incorporate the labeled precursors formate and glycine into purines. The rate of [14C]-formate incorporation was decreased by several compounds known to inhibit purine synthesis by affecting the activity by glutamine phosphoribosylpyrophosphate (PRPP) amidotransferase, the first committed enzyme in the pathway, either through decreasing the availability of PRPP, a substrate for this enzyme, or through exerting inhibition on this enzyme. PRPP availability in the leukocyte was found to be limiting for purine synthesis. Increased PRPP availability resulting from activation of PRPP synthetase by increasing inorganic phosphate (Pi) concentration caused acceleration of purine synthesis. On the other hand, no clear-cut evidence was obtained for the availability of ribose-5-phosphate in the leukocyte being rate limiting at physiological extracellular Pi concentration for PRPP generation, and thus for purine synthesis. However, the addition of methylene blue, which accelerates the oxidative pentose shunt that produces ribose-5-phosphate, resulted in acceleration of PRPP generation and of purine synthesis only when PRPP synthetase was largely activated at high Pi concentration. These results may be taken to suggest that ribose-5-phosphate availability is indeed not limiting for PRPP generation under physiological conditions. Purine synthesis de novo was accelerated more than 13-fold in the leukocytes of two gouty patients affected with partial deficiency of hypoxanthine-guanine phosphoribosyltransferase, but was normal in the leukocytes of an obligate heterozygote for this enzyme abnormality. The results domonstrate in peripheral human leukocytes the presence of the complete pathway of de novo synthesis of purine nucleotides and the manifestation in these cells of the biochemical consequences of hypoxanthine-guanine phosphoribosyltransferase deficiency, i.e., increased availability of PRPP and acceleration of purine synthesis de novo. The results indicate the usefulness of leukocytes as a model tissue for the study of purine metabolism in man.

Fatal pneumonia associated with human metapneumovirus (HMPV) in a patient with myeloid leukemia and adenocarcinoma in the lung.

We describe a clinical case of a 59 old caucasian male who was delivered to the hospital for severe pneumonia associated to human metapneumovirus. The patient suffered from a leukemia and an adenocarcinoma in the lung and died two weeks after submission due to fatal respiratory failure.

Two cases of severe obstructive pneumonia associated with an HKU1-like coronavirus.

BACKGROUND: During the last few years a number of previously undescribed viruses, including human metapneumovirus, coronaviruses SARS, NL63 and HKU1, and bocavirus, were identified in nasopharyngeal samples from patients with signs of respiratory infections. These viruses may cause mild to life-threatening infections. OBJECTIVES: Nasopharyngeal samples from hospitalized pediatric patients with respiratory disease were analysed for the presence of coronaviruses and other well known and newly identified respiratory viruses. RESULTS: Two clinical cases of a severe obstructive pneumonia, which were associated with the presence of RNA of a novel variant (subtype) of HKU1 coronavirus in the nasopharyngeal aspirates, were identified. DISCUSSION: The detection of a HKU1-like coronavirus in pediatric patients in the current study complement the most recent independent finding of similar or closely related coronaviruses in patients with respiratory diseases in France (Vabret et al. 2006) and Norway (Jonassen et al., see accompanying manuscript). These observations indicate a wide dissemination of HKU1-like coronaviruses in Europe.

Structured treatment interruptions following immediate initiation of HAART in eight patients with acute HIV-1 seroconversion.

BACKGROUND: The immunological and clinical benefits of structured treatment interruptions (STIs) during primary HIV-1 infection remain largely unclear. PATIENTS AND METHODS: Eight patients identified during primary HIV-1 infection were immediately treated with HAART and underwent subsequent STIs after reaching complete viral suppression of HIV-RNA in peripheral plasma. HAART was re-initiated if either HIV-1 RNA >5000 copies/ml, CD4-cells <200 cells/microl or symptomatic HIV-1 disease was observed. RESULTS: After treatment discontinuation, four of eight patients were able to persistently control HIV-1 viremia below 5000 copies/ml until the last time point of follow-up (median 3 years). CD4-cell counts were within the interquartile range of untreated individuals compared to historical reference data from the MACS cohort. In the remaining study subjects persistent virological control was not reached despite repeated STIs. Moreover, compared to the MACS cohort repetitive virological failures during STIs appeared to induce an accelerated decline of CD4-cells. CONCLUSION: Spontaneous HIV-1 control after treated primary HIV-1 infection was possible in four out of eight individuals, however, if STIs after treated primary infection ameliorate the overall HIV-1 disease progression remains unknown. In the absence of viral control, repetitive viral exposure during STIs might be associated with accelerated decline of CD4-cell counts.

Expression of messenger RNA species coding for a Mr 43,000 peptide associated with ferritin in human leukemia-K562 cells and its down regulation during differentiation.

In the current study it was found that K-562 erythroleukemia cells express the superheavy (S) mRNA and the 43 Kd S peptide which were recently discovered in activated T-lymphocytes. The S mRNA was identified by its cross-hybridization with ferritin H complementary DNA probe and the S peptide (Mr 43,000) was identified by its immunoprecipitation with CM-H-9 monoclonal antibody specific for placental isoferritin. During terminal differentiation by hemin the level of S mRNA decreased below detection, with a concomitant diminution in the biosynthesis of the S peptide. In contrast, a significant increase in the level of ferritin light (L) and heavy (H) mRNAs was observed, resulting in an increase in the rate of biosynthesis of the H and L ferritin subunits. Removal of iron by desferrioxamine reduced the biosynthesis of ferritin L and H chains without altering the level of the corresponding mRNAs. Treatment with desferrioxamine did not affect either the level of S mRNA or the biosynthesis of the S peptide. This is a demonstration of a new mRNA species which is expressed in leukemic cells and is down-regulated during cell differentiation.

Protection against parenteral HIV-1 infection by homozygous deletion in the C-C chemokine receptor 5 gene.

OBJECTIVES: To investigate the role of the CC chemokine receptor 5 (CCR5) for parenteral transmission of HIV-1. DESIGN: The prevalence of the delta32 deletion within the CCR5 gene was determined in a cohort of 207 patients, who had received documented amounts of non-antibody-tested and non-inactivated clotting factor concentrate. METHODS: Chromosomal DNA of haemophiliacs was isolated from whole blood. A portion of the CCR5 gene spanning the delta32 deletion was amplified by PCR. The resulting DNA fragments were analysed by agarose gel electrophoresis. RESULTS: The rate of HIV-1 infection was correlated strongly with increasing amounts of inoculated clotting factor concentrate. None of the HIV-positive patients (n = 129) had the delta32/delta32 genotype, whereas 12 out of 78 HIV-negative haemophiliacs had the homozygous delta32 deletion. CONCLUSIONS: The delta32/delta32 genotype was highly protective against HIV-1 infection, even in patients who had received millions of non-inactivated clotting factor units. As it is likely that in the early 1980s plasma pools were contaminated not only with monocyte-tropic HIV-1 strains, CCR5 appears to be the major mediator of HIV-1 infection. Furthermore, we conclude that there must be other protective mechanisms in multiply exposed non-infected haemophiliacs who have wild-type CCR5.

A computerized system for continuous physiologic data collection and analysis: initial report on mean arterial blood pressure in very low-birth-weight infants.

A system for continuous measurement and analysis of mean arterial blood pressure (MABP) by microcomputer is presented. The system allows prolonged recording and maintenance of fine detail by sequential evaluation and storage of up to 3,600 data points per hour. Fifteen preterm appropriate-for-gestational-age (AGA) infants weighing less than or equal to 1,500 g (very low birth weight) who were free of pulmonary and neurologic disease were monitored continuously from birth to 5 days of age. MABP was recorded via an umbilical arterial catheter with a pressure transducer and module interfaced with the microcomputer. Software was developed to analyze this stored data rapidly. MABP was found to correlate significantly with gestational age from 3 to 15 hours of age (P less than .05). Significant correlation was rare after 20 hours of age. MABP increased as a function of postnatal age in 11 infants. This increase was greater (0.31 to 0.54 mm Hg/h) for the least mature infants (27 to 29 weeks of gestation). The increase for the most mature infants (31 to 32 weeks of gestation) was low (0 to 0.24 mm Hg/h), and in three infants a small negative slope was seen. The steep rise in MABP during the first 40 hours of life in the least mature infants may be due to the perfusion requirements of extrauterine life. These pressures may be at or near the threshold for rupture of immature vascular beds such as are found in the subependymal germinal matrix and thus predispose to intraventricular hemorrhage.

Preparation and characterization of monoclonal antibodies specific to placenta ferritin.

Ferritins are a group of isomeric proteins which function as the major iron-storage protein of mammalian tissues. Some of the isoferritins have low isoelectric points, and are found in placenta and in malignant tissues and have therefore been termed carcinofetal ferritins. With the use of hybridoma technology, monoclonal antibodies (McAbs) specific to human placenta ferritin(s) were produced in order to characterize the heterogeneity of the molecule and to answer the question whether a specific antigenic determinant is associated with placenta and/or carcinofetal ferritin(s). Two McAbs designated H-9 and G-8 were developed. McAb H-9 bound specifically and exclusively to the ferritin isolated from human placenta, whereas G-8 McAb bound to placenta ferritin and cross-reacted with ferritins isolated from human spleen and liver. No cross-reaction was observed between H-9 and G-8 reactive determinants. It was found further that the two antigenic determinants - the one recognized by G-8 and that recognized by H-9 McAbs - are molecularly associated on placenta ferritin. The results of this study led us to term the G-8 a 'common' ferritin antigenic determinant and H-9 a 'private' embryonic ferritin determinant.

Physical exercise and psychological health.

For individuals who are just beginning to exercise, the very unfit, the elderly and persons suffering from psychiatric disorders, low intensity activity has important potential psychological benefits. Several studies indicate that mental health can be improved by low- or moderate-intensity activity. In 2 studies it could be demonstrated that aerobic exercise plus counselling was more effective in the treatment of depressive disorders than counselling alone. Cross-sectional community studies clearly reveal that after controlling for potential sociodemographic and health-related confounding variables the risk of depression is significantly higher for physically inactive individuals compared with regular exercisers. No final conclusions can be drawn from longitudinal field studies on the predictive value of physical activity on the degree of depressive symptoms. Several biological and psychological hypotheses have been proposed to explain the association between physical activity and mental health, however, there is still a lack of an integrated theoretical model.

Failure of double protease inhibitor therapy as a salvage therapy for HIV-infected patients resistant to conventional triple therapy.

A therapeutic dilemma arises once HIV-infected patients develop a break-through of HIV-replication under potent antiretroviral therapy. Therefore, we studied whether patients (n = 12) who failed double nucleoside reverse transcriptase (NRTI) plus indinavir or ritonavir triple therapy can be rescued when therapy is switched to double protease inhibitor (PI) treatment (nelfinavir and hard gel saquinavir) and stavudine. With the rescue regimen HIV-RNA levels initially dropped from 148,571 +/- 45,258 copies/ml to 9,310 +/- 6, 965 copies/ml at week 4 (p = 0.0117). However, virus load subsequently increased to almost baseline levels (131,230 +/- 37,743 copies/ml) at week 12. Likewise, CD4-cell counts could only be stabilized initially (baseline 267 +/- 51; week 4 296 +/- 65 cells/microl), but gradually declined thereafter (216 +/- 34 cells/microl week 12). Before therapy was switched, the viral protease gene from 5 analyzed patients showed 3-5 amino acid substitutions. Moreover, 4 of these patients had one amino acid substitution associated with resistance to nelfinavir. Our data suggest that HIV-infected patients resistant to indinavir or ritonavir and double NRTI combination therapy respond to double PI nelfinavir/saquinavir and D4T rescue therapy only initially but have no sustained benefit.

In vitro cytopathogenicity of the human immunodeficiency virus (HIV)-1 predicts survival in HIV-infected hemophiliacs independent from CD4 cell count.

In addition to quantification of viral load the graded cytopathogenicity of the human immunodeficiency virus may provide prognostic information for the course of HIV infection. However, the prognostic value of graded cytopathogenicity in addition to the CD4 count has not been evaluated in a large longitudinal study. Therefore a total of 216 HIV-seropositive hemophiliacs have been followed up from 1985 to 1998 (mean follow-up 70.4 +/- SD 26 months, median 72, range: 12 to 120 months). In vitro virulence was determined according to cytopathic effects on freshly isolated PBMC of healthy donors and graded from A (strongest cytopathogenic effect) to D (no cytopathic isolate effect). Survival was analyzed among patients with different virus isolates by Kaplan-Meier statistics (log rank) and factors independently associated with decreased survival were analyzed by Cox hazard regression analysis. - A virus isolate A was found in 22 (10.2%) patients, a virus isolate B was found in 21 (9.3%) patients, a virus isolate C was found in 9 (4.2%) and a virus isolate D was found in 10 (4.2%) patients. Mean survival times were 48 months (95% Confidence Interval (CI) = 36 - 60) in patients with isolate A, 72 months (CI = 36 - 108) with isolate B, 84 months (CI = 48-120) with isolate C, 72 months (60 - 96) with isolate D and 96 months (CI = 96 - 108) in patients with a negative virus culture (p < 0.001). Cox regression analysis indicated significant associations with outcome for young age (p <0.001), positive virus culture (p < 0.0001) and CD4 count (p < 0.0001) as independent predictors of survival. The presence of an isolate A revealed the strongest odds ratio (6.3, 95% CI 2.9-13.2). Our data indicate that the presence of a virus isolate A represents a strong risk factor for mortality in the course of HIV infection. Besides quantification of viral load and CD4 count, the graded cytopathogenicity may provide additional information for early and aggressive antiretroviral treatment, since the mean survival in patients with cytopathogenic virus isolates is reduced significantly.

[The human bocavirus: pathogen in airway infections?]. / Das humane Bocavirus: Erreger von Atemwegsinfektionen?

The human Bocavirus (HBoV), the second member of the parvovirus family, which displays pathogenicity in humans, has been described in 2005 by Allander et al.. It seems to be distributed worldwide and has been isolated mainly in infants and children with respiratory tract infection. This review covers all studies published on HBoV to February 2007 and discusses this emerging viral pathogen from the perspective of inpatient medical treatment centers.

Suppressor cel activity of ferritin-bearing lymphocytes in patients with breast cancer.

In patients with early stages (I, II) of breast cancer we identified a subset of circulating lymphocytes that carry ferritin on their surface. No such lymphocytes were identified in normal women nor in women with benign breast disease. These cells did not form spontaneous rosettes with sheep red blood cells. Further studies revealed that in vitro treatment of the patients' lymphocytes with levamisole resulted n the removal of the surface ferritin and in an increase in the reactivity of the lymphocytes in mixed lymphocyte culture (MLC). Separation of the ferritin-positive lymphocytes from the E-rosetting T cells resulted in an increased reactivity of the patients' T cells in MLC. Readdition of the fraction containing the ferritin-positive cells to a mixed lymphocyte culture resulted in a decrease in the proliferative response of the patients' T lymphocytes. It is suggested that the ferritin-positive lymphocytes in breast cancer patients represent an active suppressor cell subset.