Baseline Resistance and Virological Outcome in Patients with Virological Failure who Start a Regimen Containing Abacavir: Eurosida Study

Objectives

To investigate the ability of several HIV-1 drug-resistance interpretation systems, as well as the number of pre-specified combinations of abacavir-related mutations, to predict virological response to abacavir-containing regimens in antiretroviral therapy-experienced, abacavir-naive patients starting an abacavir-containing regimen in the EuroSIDA cohort.

Patients and methods

A total of 100 HIV-infected patients with viral load (VL) >500 copies/ml who had a plasma sample available at the time of starting abacavir (baseline) were included. Resistance to abacavir was interpreted by using eight different commonly used systems that consisted of rules-based algorithms or tables of mutations. Correlation between baseline abacavir-resistance mutations and month 6 virological response was performed on this population using a multivariable linear regression model accounting for censored data.

Results

The baseline VL was 4.36 log10 RNA copies/ml [interquartile range (IQR): 3.65–4.99 log10 RNA copies/ml] and the median CD4 cell count was 210 cells/μl (IQR: 67–305 cells/μl). Our patients were pre-exposed to a median of seven antiretrovirals (2–12) before starting abacavir therapy. The median (range) number of abacavir mutations (according to the International AIDS Society-USA) detected at baseline was 3.5 (0–8). Overall, the Kaplan–Meier estimate of the median month 6 VL decline was 0.86 log10 RNA copies/ml [95% confidence intervals (95% CI): 0.45–1.24]. The VL in those patients ( n=31) who intensified treatment by adding only abacavir decreased by a median 0.20 log10 RNA copies/ml (95% CI: -0.18; +0.94). The proportion of patients who harboured viruses fully resistant to abacavir among the eight genotypic resistance interpretation algorithms ranged from 12% [Agence Nationale de Recherches sur le SIDA (ANRS)] to 79% [Stanford HIV RT and PR Sequence Database (HIVdb)]. Some interpretation systems showed statistically significant associations between the predicted resistance status and the virological response while others showed no consistent association. The number of active drugs in the regimen was associated with greater virological suppression (additional month 6 VL reduction per additional sensitive drug=0.51, 95% CI: 0.15–0.88, P=0.006); baseline VL was also weakly associated (additional month 6 VL reduction per log10 higher=0.30, 95% CI: -0.02; +0.62, P=0.06). In contrast, the number of drugs previously received was associated with diminished viral reduction (additional month 6 VL reduction per additional drug=-0.14, 95% CI: -0.28; 0.00, P=0.05).

Conclusions

Our results revealed a high degree of variability among several genotypic resistance interpretation algorithms currently in use for abacavir. Therefore, the interpretation of genotypic resistance for predicting response to regimens containing abacavir remains a major challenge.

Phase I dose-finding study of biweekly irinotecan in combination with fixed doses of 5-fluorouracil/leucovorin, gemcitabine and cisplatin (G-FLIP) in patients with advanced pancreatic cancer or other solid tumors

This phase I trial was initiated based on encouraging clinical data with 5-fluorouracil (5-FU)/leucovorin (LV), gemcitabine and cisplatin (G-FLIP) in the therapy of solid tumors. In this trial, G-FLIP has been modified to facilitate outpatient administration and to optimize sequence-dependent synergistic activity. Treatment consisted of biweekly (once every 14 days) cycles of sequential gemcitabine 500 mg/m, irinotecan per dose escalation schedule, bolus 5-FU 400 mg/m and LV 300 mg on day 1 followed by a 24-h 5-FU infusion 1500 mg/m, followed by cisplatin 35 mg/m on day 2. The irinotecan starting dose was 80 mg/m and escalated by 20 mg/m in cohorts of three patients until the maximum tolerated dose (MTD) was defined. Twenty-three patients were enrolled (13 men/10 women) with the following cancers: 11 pancreatic, five gallbladder, three squamous cell carcinoma of the head and neck, one hepatocellular carcinoma, one melanoma, one gastric, and one breast cancer. Median patient age was 63 years (range 44-78) and median Karnofsky performance status (KPS) was 80. Patients received a median of 8 cycles (range 1-16) over five irinotecan dose levels (80, 100, 120, 140 and 160 mg/m). Dose-limiting toxicity consisting of grade 3 nausea/vomiting despite aggressive anti-emetic therapy occurred in one patient at dose level 1 and three patients at dose level 3. Grade 3-4 hematological toxicities per patient consisted of thrombocytopenia (3%), anemia (6%), thrombosis (23%), neutropenia (16%) and neutropenic fever (10%). Of 18 patients evaluable for response, one complete response (pancreatic) and eight partial responses (three gallbladder, two pancreatic, two head and neck, and one breast) were attained. Seven patients had disease stabilization (five pancreatic, one hepatocellular and one gastric) for a median of 16 weeks (range 10-22). Median time to disease progression among all 23 patients enrolled to the phase I portion of the trial was 20.5 weeks (range 4-37). We conclude that G-FLIP is a novel outpatient chemotherapy regimen with acceptable toxicity at the maximum tolerated irinotecan dose of 120 mg/m. The phase II trial of G-FLIP using an irinotecan dose of 120 mg/m for patients with metastatic pancreatic cancer is ongoing.

Elimination of microbubbles from the extracorporeal circuit: dynamic bubble trap versus arterial filter

BACKGROUND

Open heart surgery is associated with important risk of cerebral and peripheral organ dysfunction, attributed in part to microbubbles generated in or not eliminated from the ECC. For elimination of microbubbles, a dynamic bubble trap (DBT) was developed for the arterial line of ECCs.

METHODS

Bubble eliminating properties of an arterial filter were evaluated in four CABG patients and compared to the performance of the DBT in four patients. One patient received both devices.

RESULTS

Elimination of bubbles between 40-120 microm was significantly higher with the DBT (88% vs. 57% with arterial filter, p=0.034). Reduction of bubbles below 40 microm was equivalent in both groups. The combination of both devices was most effective (94% for bubbles >40 microm).

CONCLUSION

Arterial filter and DBT are equally effective in elimination of smaller gas bubbles. However, bigger bubbles possibly causing cerebral and peripheral organ damage are eliminated to a greater degree by the DBT.

Determinants of long-term highly active antiretroviral treatment efficacy

OBJECTIVES

Predictors of the efficacy of highly active antiretroviral therapy (HAART) have been investigated in several studies. To increase current knowledge, the study aimed to acquire comprehensive data over an extended observation time, to obtain information on possible performance differences among individual drugs, and to identify factors with influence on the initial response to a HAART regimen and the sustainability of the response.

METHODS

The data were obtained from a prospective, single University Medical School HIV cohort. Clinical, laboratory, and treatment parameters for 475 patients were collected over 4.5 years. HAART efficacy was determined by analysis of variance and multivariate survival analysis.

RESULTS

The overall initial complete response (CR) (<500 HIV-1 RNA copies/mL) was 76.3%. Use of indinavir [odds ratio (OR)=2.747, P=0.0009] and the number of new nucleoside reverse transcriptase inhibitors (NRTIs) (OR=1.862, P=0.0017) were positively associated with CR, while initial peripheral blood HIV RNA concentration (OR=0.383, P<0.0001), use of saquinavir hard gel capsules (OR=0.531, P=0.0302), the number of successive HAART regimens (OR=0.631, P<0.0001), and the number of previously used NRTIs (OR=0.728, P=0.0081) were negatively associated with CR. Sustainability of CR was positively correlated with use of indinavir [hazard ratio of relapse (HR)=0.255, P<0.0001] and haemoglobin levels (HR=0.873, P=0.0124), but negatively correlated with initial HIV RNA concentration (HR=1.273, P=0.0003) and the number of previously used NRTIs (HR=1.587, P<0.0001). A higher number of consecutive HAART regimens was associated with a markedly reduced CR, but with only a slightly higher risk of relapse.

CONCLUSIONS

The initial response to HAART, as well as long-term efficacy, depends strongly on a few fundamental parameters that can easily be assessed in a clinical setting. There is a need for effective suppression of HIV replication over decades, and these factors should be considered early in treatment planning to identify patients with an unfavourable profile of risk factors for treatment failure.

Improved cerebral protection through replacement of residual intracavital air by carbon dioxide: a porcine model using diffusion-weighted magnetic resonance imaging

BACKGROUND

Major risk of central or peripheral organ damage is attributed to air embolism from incompletely de-aired cardiac chambers after cardiac operations. Replacement of air by carbon dioxide insufflation into the thoracic cavity is widely used. Diffusion-weighted magnetic resonance imaging of the brain detects ischemia within minutes after onset. The reversibility of ischemia in cerebral tissue after massive gaseous emboli has not yet been described.

METHODS

After selective catheterization of a common carotid artery in 15 pigs, boli of 1 mL/kg body weight of air (n = 5) or carbon dioxide (n = 5, "low dose") were applied. Five pigs received 2 mL/kg body weight of carbon dioxide ("high dose"). Diffusion-weighted magnetic resonance imaging of the brain was performed 2, 5, 10, 15, and 25 minutes after embolization.

RESULTS

All animals of the "air" group showed important circulatory reactions leading to death of 2 animals. In the whole group, diffusion-weighted magnetic resonance imaging revealed irreversible hyperintense signals in both hemispheres. In the low-dose group, no change in signal intensity was observed in 2 pigs, and 3 others showed reversible changes in signal intensity, without important circulatory reactions. In 3 animals of the high-dose group, hyperintense signals were reversible, but 2 others presented with bilateral, irreversible signals in diffusion-weighted magnetic resonance imaging, accompanied by minor circulatory reactions.

CONCLUSION

In contrast to the dramatic effect of air emboli, identical quantities of carbon dioxide injected into cerebral arteries of the pigs were not associated with major clinical symptoms. The early reversibility of ischemic reactions visualized in diffusion-weighted magnetic resonance imaging encourages the use of carbon dioxide insufflation as a protective method in cardiac surgery.

Decline in the AIDS and death rates in the EuroSIDA study: an observational study

BACKGROUND

Since the introduction of highly active antiretroviral therapy (HAART), little is known about whether changes in HIV-1 mortality and morbidity rates have been sustained. We aimed to assess possible changes in these rates across Europe.

METHODS

We analysed data for 9803 patients in 70 European HIV centres including ones in Israel and Argentina. Incidence rates of AIDS or death were calculated for overall and most recent CD4 count in 6-monthly periods and in three treatment eras (pre-HAART, 1994-1995; early-HAART, 1996-1997; and late-HAART, 1998-2002).

FINDINGS

The incidence of AIDS or death fell after September, 1998, by 8% per 6-month period (rate ratio 0.92, 95% CI 0.88-0.95, p<0.0001). When AIDS and death were analysed separately, the incidence of all deaths during the late-HAART era was significantly lower than that during the early-HAART era in patients whose latest CD4 count was 20 cells/microL or less (0.43, 0.35-0.53, p<0.0001), but at higher CD4 counts, did not differ between early-HAART and late-HAART. Incidence of AIDS was about 50% lower in late-HAART than in early-HAART, irrespective of latest CD4 count (p<0.0001). In multivariate Cox's models, with early-HAART as the reference, there was an increased risk of AIDS (relative hazard 1.39; 95% CI 1.16-1.67, p=0.0004) and all deaths (1.29; 1.08-1.56, p=0.0065) in the pre-HAART era, and a reduced risk of AIDS (0.62; 0.50-0.77, p<0.0001) and all deaths (0.66; 0.53-0.82, p=0.0002) in the late-HAART era.

INTERPRETATION

The initial drop in mortality and morbidity after the introduction of HAART has been sustained. Potential long-term adverse effects associated with HAART have not altered its effectiveness in treating AIDS.

Left ventricular thrombus capture by an intra-aortic filter device

Left ventricular aneurysmectomy in patients with mobile, protruding thrombi is associated with increased risk of neurological complications due to loss during left ventricular luxation or embolisation of residual thrombotic material after incomplete removal. Embolisation can be prevented by application of an intra-aortic filter device. Here, we report on a case involving an important left ventricular thrombus captured in a patient referred for coronary artery bypass grafting, left ventricular aneurysmectomy, and thrombectomy.

Optimal carbon dioxide application for organ protection in cardiac surgery

BACKGROUND

Cardiac surgery is associated with an important risk of central or peripheral organ damage, attributed in part to air embolism from incompletely deaired cardiac chambers. Insufflation of carbon dioxide into the thoracic cavity is widely used for organ protection in cardiac surgery.

METHODS

In patients operated on through a sternotomy, the gas was insufflated through a standard cardioplegia line (group I, n = 10) or a Jackson-Pratt drain (group II, n = 10), with flow rates of 2, 4, and 6 L/min. In patients undergoing mitral valve surgery through a right anterolateral minithoracotomy, application through a gas port (group III, n = 10) was compared with application through a Veress needle (group IV, n = 10). In groups I and IV measurements were repeated with a gauze sponge to divert the gas stream.

RESULTS

At a flow of 2 L/min, carbon dioxide levels in the thoracic cavity reached 52% +/- 30% in group I and increased to 81% +/- 27% when a gauze sponge was used. In group II a level of 91% +/- 5% was achieved. In minimally invasive procedures carbon dioxide levels reached 92% +/- 6% in group III and 60% +/- 25% in group IV without a gauze sponge and 97% +/- 2% in group IV with a gauze sponge. Increasing flow rates from 2 to 6 L/min decreased carbon dioxide levels in the thoracic cavity. Arterial blood gas analysis did not reveal critical levels of partial pressure of carbon dioxide at any time.

CONCLUSIONS

For optimized carbon dioxide concentrations during cardiac procedures, jet effects in the thoracic cavity have to be avoided. The highest levels were achieved with infusion lines covered by a gauze sponge or a perforated drain for conventional operations and a sponge-covered Veress needle or a gas port for minimally invasive approaches.

Coordination-number dependence of magnetic hyperfine fields at (111)Cd on Ni surfaces

Ferromagnetic Ni surfaces were investigated on an atomic scale using the perturbed angular correlation spectroscopy probe (111)Cd. A comprehensive set of data for magnetic hyperfine fields (B(hf)) at various probe sites is presented. A field variation from -7 T in Ni bulk to the surprisingly large value of 16 T at the adatom position on Ni(111) is observed. A continuous nonlinear dependence is found, correlating the experimental B(hf) values with the number of their nearest Ni neighbors. The data are discussed on the basis of recent calculations on B(hf) values at sp-element impurities on ferromagnetic surfaces.

Electric quadrupolar contribution to the nuclear spin-lattice relaxation of Ir in Fe

We report on the first quantitative determination of the electric quadrupolar contribution to the nuclear spin-lattice relaxation in a transition metal. For 186Ir and 189Ir in Fe we have determined the magnetic and the electric quadrupolar part of the relaxation for magnetic fields between 0.01 and 2 T. The quadrupolar part gives information on the role of the orbital motion of the electrons for the relaxation process. Our results prove that the unexpected high relaxation rates in Fe and their magnetic field dependence are due to a nonorbital relaxation mechanism.

A new accelerated vaccination schedule for rapid protection against hepatitis A and B

BACKGROUND

Increasing travel stresses the requirement for rapid protection against infections such as hepatitis A and B.

METHODS

This randomised, multicentre study investigated an accelerated vaccination schedule using a combined hepatitis A and B vaccine (Twinrix, Smithkline Beecham Biologicals) compared with simultaneous administration of the two corresponding monovalent vaccines. The combined vaccine was administered on days 0, 7 and 21, whereas the comparison group received hepatitis A vaccine on day 0 and hepatitis B vaccine on days 0, 7 and 21. All subjects received booster vaccination at month 12.

RESULTS

At month 1, 100% of subjects in the combined group and 99% of the controls were seropositive for anti-HAV antibodies. The corresponding seroprotection rates for anti-HBs antibodies were 82.0 and 83.9%, respectively. Examination of the 95% confidence intervals (CIs) for the treatment differences showed the two vaccines to be equivalent in terms of immunogenicity 1 week after the initial vaccination course. Just prior to the booster, the seropositivity rate for anti-HAV was 96.2% in the combined group and 95% in the control group. For anti-HBs, this was 94 and 91.6%, respectively. All subjects were seropositive for anti-HAV and seroprotected against hepatitis B at month 13. The anti-HAV GMCs were 9571mIU/ml with the combined vaccine and 5206mIU/ml in control subjects. The anti-HBs titre was 26002 and 29,196mIU/ml, respectively. Both groups had a similar reactogenicity profile.

CONCLUSIONS

The accelerated schedule of the combined vaccine provides a good immune response against hepatitis A and B antigens and is suitable for last minute immunisation.

Response to Antiretroviral Therapy among Patients Exposed to Three Classes of Antiretrovirals: Results from the Eurosida Study

There is an increasing proportion of HIV-positive patients exposed to all licensed classes of antiretrovirals, and the response to salvage regimens may be poor. Among over 8500 patients in EuroSIDA, the proportion of treated patients exposed to nucleosides, protease inhibitors (PIs) and non-nucleoside reverse transcriptase inhibitor (NNRTI) increased from 0% in 1996 to 47% in 2001. Four-hundred-and-thirteen patients, who had failed virologically two highly active antiretroviral therapy (HAART) regimens and experienced all three main drug classes, started a salvage regimen of at least three drugs, in which at least one new PI or NNRTI was included. Median viral load was 4.7 log copies/ml [Interquartile range (IQR) 4.2–5.2], CD4 lymphocyte count 150/mm3 (IQR 60–274/mm3) and follow-up 14 months. Of these patients, 283 (69%) subsequently experienced at least a 1 log decline in viral load and 202 (49%) achieved a viral load <500 copies/ml. Conversely, the CD4 count halved from the baseline value in 88 (21%), and 45 (11%) experienced a new AIDS-defining disease. In multivariable analyses, a 1 log viral load reduction was related to baseline viral load [relative hazard (RH) 1.27 per 1 log higher; P=0.008], a previous viral load of less than 500 copies/ml (RH 1.69; P=0.002), more recent initiation of the regimen (RH 1.36 per year more recent; P=0.02), number of new drugs in the regimen (RH 1.20 per drug; P=0.02), time since start of antiretroviral therapy (RH 0.94 per extra year; P=0.035) and time spent on HAART with viral load >1000 copies/ml (RH 0.96 per extra month; P=0.0001). Analysis of factors associated with CD4 count decline and new AIDS disease also indicated improved outcomes in more recent times and a tendency for a better response in those starting more new drugs, but no relationship with the total number of drugs. Outcomes in people starting salvage regimens appear to depend on the number of new drugs started but not on the total number of drugs being used.

Conventional carbon dioxide application does not reduce cerebral or myocardial damage in open heart surgery

BACKGROUND

Open heart surgery is associated with a significant risk of cerebral and myocardial dysfunction, which is attributed in part to air embolism from incompletely deaired cardiac chambers. To evaluate the impact of carbon dioxide (CO2) insufflation to the thoracic cavity, a prospective randomized study was designed.

METHODS

A total of 62 elective patients were randomly assigned to CO2 insufflation (group I, n = 31) or control (group II, n = 31). According to the Parsonnet risk score, 16 patients in group I (52%) and 10 patients in group II (32%) were categorized as being at either high risk or extremely high risk.

RESULTS

In group II, perioperative mortality was 16.1% (5 patients); in group I, 1 patient died (ns). Creatine kinase MB isoenzyme, as a marker of myocardial damage, was more elevated in group I after surgery (38.0 +/- 4.1 vs 28.0 +/- 2.1, p = 0.02). Neurocognitive test scores did not reveal significant postoperative differences between groups.

CONCLUSIONS

Although mortality was lower with CO2 insufflation, no benefit could be demonstrated for markers of cardiac ischemic damage or neurocognitive outcome in this high-risk population. As CO2 concentrations in the thoracic cavity did not necessarily reach anticipated levels, our method of application is in question.

Treatment of acute hepatitis C with interferon alfa-2b

BACKGROUND

In people who are infected with the hepatitis C virus (HCV) chronic infection often develops and is difficult to eradicate. We sought to determine whether treatment during the acute phase could prevent the development of chronic infection.

METHODS

Between 1998 and 2001, we identified 44 patients throughout Germany who had acute hepatitis C. Patients received 5 million U of interferon alfa-2b subcutaneously daily for 4 weeks and then three times per week for another 20 weeks. Serum HCV RNA levels were measured before and during therapy and 24 weeks after the end of therapy.

RESULTS

The mean age of the 44 patients was 36 years; 25 were women. Nine became infected with HCV through intravenous drug use, 14 through a needle-stick injury, 7 through medical procedures, and 10 through sexual contact; the mode of infection could not be determined in 4. The average time from infection to the first signs or symptoms of hepatitis was 54 days, and the average time from infection until the start of therapy was 89 days. At the end of both therapy and follow-up, 43 patients (98 percent) had undetectable levels of HCV RNA in serum and normal serum alanine aminotransferase levels. Levels of HCV RNA became undetectable after an average of 3.2 weeks of treatment. Therapy was well tolerated in all but one patient, who stopped therapy after 12 weeks because of side effects.

CONCLUSIONS

Treatment of acute hepatitis C with interferon alfa-2b prevents chronic infection.

Cortical fibroblast culture from human biopsies

BACKGROUND

Tubulointerstitial fibrosis is an integral part of progressive renal disease. Human cortical fibroblasts are believed to be key effector cells in fibrogenesis. Thus, a reliable culture of these cells is necessary for studies of their pathophysiology.

METHODS

Cortical fibroblast culture from routine kidney biopsies were analyzed and the cells were characterized. Indirect immunofluorescence staining was done after the first passage for cytokeratin, vimentin, alpha-smooth muscle actin, CD 44, CD 54, CD 68, collagen types I, III, and HLA-DR. We then assessed the utility of the putative fibroblast markers CD 90, prolyl-4-hydroxylase (P4H) and F1b in simultaneous stainings of tubular epithelial cells.

RESULTS

During the study period, 49 biopsy cores were cultured and cortical fibroblasts could be successfully established in 21 cases (42.9%). There was no relation between the success rate of culture and the degree of interstitial fibrosis, but an association was seen with the time of completion of the first passage. There was a negative correlation between the extent of scarring and the percentage of cytokeratin positive cells (r = -0.66, p < 0.001). All primary fibroblasts were negative for factor VIII, HLA-DR, CD 68, and cytokeratin. They expressed alpha-smooth muscle actin and collagen types I and III to variable degrees. There was a robust correlation between the percentage of alpha-smooth muscle actin positive cells and interstitial scarring but no such association with collagen type I or type III positive cells. The three putative fibroblast markers did not prove useful in differentiating between tubular epithelial cells and fibroblasts. However, since only fibroblasts stained positive for CD 90 and negative for cytokeratin, these two markers may suffice to distinguish fibroblasts from other renal cellular elements.

CONCLUSIONS

Cortical renal fibroblasts can be easily cultured from kidney biopsy cores, though the success rate of pure cultures is below 50%. Staining for CD 90 and cytokeratin may suffice for initial characterization of these cells.

Procalcitonin as a parameter of disease severity and risk of mortality in patients with Plasmodium falciparum malaria

The serum levels of procalcitonin (PCT) in Plasmodium falciparum malaria were evaluated for clinical significance in 66 nonimmune and semi-immune patients. Of the 66 patients, 36 had uncomplicated malaria, 24 had severe and complicated malaria, and 6 had fatal malaria (5 from previous studies). Pretreatment PCT concentrations were closely correlated with parasitemia. Concentrations were lowest in semi-immune patients with uncomplicated malaria, compared with those in nonimmune patients (geometric mean concentrations [GMCs], 1.07 and 2.37 ng/mL, respectively), and were highest in severe and complicated cases (GMC, 10.67 ng/mL; P<.001 among all subgroups). Six of 7 patients with PCT concentrations >25 ng/mL died. PCT concentrations decreased on day 2 of treatment in survivors but not in patients with fatal outcome. Thus, repeated PCT measurements may provide useful prognostic information, especially in medical centers that are not experienced in parasite density determination.

Reactivation of hepatitis B virus replication accompanied by acute hepatitis in patients receiving highly active antiretroviral therapy

We describe 2 patients who were initially positive for antibodies to hepatitis B surface antigen and who experienced a strong and sudden increase of hepatitis B virus (HBV) replication during highly active antiretroviral therapy (HAART). We found that reactivation of HBV replication during HAART can occur independently of lamivudine resistance or withdrawal of lamivudine, and in spite of increasing CD4(+) cell counts.

Regional differences in presentation of AIDS in Europe

Data were collected on 6578 patients diagnosed with AIDS at 52 clinical centres in 17 European countries during an 1-year period from 1979 to 1989. The centres were divided into four regions, North, Central, Southeast, and Southwest. Differences in the incidence of most AIDS-defining opportunistic infections and malignancies were found. After adjusting for known possible confounders, statistically significant differences between regions remained. Pneumocystis carinii pneumonia (PCP) was more common in Northern Europe, Kaposi's sarcoma and toxoplasmosis in Central Europe, cytomegalovirus retinitis in South-eastern Europe, and extrapulmonary tuberculosis in South-western Europe. These differences we attribute primarily to different degrees of exposure to the respective underlying pathogens. The prevalence of these and other micro-organisms will determine the clinical course of HIV infections in parts of Eastern Europe and elsewhere where the virus now is spreading.

CD4 alphabeta T lymphocytes express high levels of the T lymphocyte antigen CTLA-4 (CD152) in acute malaria

The role of T lymphocytes in human acute malaria remains under debate. The kinetics of T cell activation in acute malaria were investigated, with emphasis on CTLA-4 (CD152). In patients with malaria, CTLA-4 expression by CD4 alphabeta T lymphocytes was highly increased. After initiation of antiplasmodial treatment, it returned to control values within a few days. gammadelta T cells, which also are implicated in the pathogenesis of human malaria, did not express CTLA-4. The level of CTLA-4 expression at the time of hospital admission was correlated positively with other markers of disease severity-the peak of the parasitemia and the peak of serum neopterin levels. These results show that CTLA-4 is a sensitive and dynamic marker for T lymphocyte activation. Its strong increase in acute malaria argues for the involvement of T cells in the human immune response to plasmodia.

Increased levels of soluble Fas ligand in serum in Plasmodium falciparum malaria

Levels of soluble Fas ligand (sFasL) in serum were elevated in patients with Plasmodium falciparum malaria and showed a significant decline during disease course. sFasL levels that were elevated before antimalarial treatment began correlated significantly with depressed total lymphocyte and T-cell counts. These data suggest that Fas-induced apoptosis might play a role in malaria-associated lymphopenia.

Comparative evaluation of two branched-DNA human immunodeficiency virus type 1 RNA quantification assays with lower detection limits of 50 and 500 copies per milliliter

We have comparatively evaluated Quantiplex version 3.0 and version 2. 0 on 133 plasma samples and a repetitive dilution series. Version 3. 0 yielded higher human immunodeficiency virus RNA values, and the ratio of version 3.0 results to version 2.0 results decreased from 3. 47 below 1,000 copies/ml to 1.97 above 50,000 copies/ml [linear regression, log (version 3.0) = 0.915 + 0.871 x log (version 2.0); r(2) = 0.952].