Trends and interaction of HIV-1 and HIV-2 in Guinea-Bissau, west Africa: no protection of HIV-2 against HIV-1 infection

OBJECTIVES

To study trends in the prevalence and incidence of HIV-1 and HIV-2 infections in Guinea-Bissau over the last 7 years, and to evaluate the protective effect of HIV-2 against HIV-1 infection.

DESIGN

Prospective follow-up of a cohort of police officers in Guinea-Bissau, and sentinel surveillance of pregnant women in Bissau.

METHODS

Participants in the police cohort were tested regularly for antibodies to HIV and Treponema pallidum, and information about sexual risk behaviour and a history of sexually transmitted diseases was obtained. Simultaneously, pregnant women at the maternity wards at the National Hospital in Bissau were screened annually for HIV antibodies. To evaluate changes in prevalence and incidence of HIV in the police cohort, the study period was divided into three time strata with 2-3 years in each stratum. For the evaluation of a protective effect of HIV-2 on subsequent HIV-1 infection, two multivariate Poisson regression models were constructed, adjusting for different selected confounding variables.

RESULTS

Between 1990 and 1997, 2637 police officers were included in the cohort study, 90.7% of whom were male. The overall prevalence of HIV-1 was 0.9%, of HIV-2 it was 9.7% and of HIV-1 and HIV-2 dual reactivity it was 0.5%. For pregnant women the prevalence rates were 0.9, 5.5 and 0.2% for HIV-1, HIV-2 and dual reactivity respectively. The prevalence of HIV-1 increased significantly whereas the prevalence of HIV-2 declined significantly during the study period, among both police officers and pregnant women. The total incidence of HIV-1 and HIV-2 was 0.74 and 0.83 per 100 person-years respectively in the police cohort. The incidence of HIV-1 increased slightly from 0.62 to 0.78 per 100 person-years (not significant), whereas the incidence of HIV-2 declined significantly from 0.90 to 0.35 per 100 person-years over the study period. Seven police officers seroconverted from HIV-2 to dual reactivity (1.22 per 100 person-years). The adjusted incidence ratio of acquiring HIV-1 infection among HIV-2-positive subjects compared with HIV-negative subjects was 1.65 [95% confidence interval (CI), 0.73-3.74] and 1.98 (95% CI, 0.80-4.87), depending on the confounding variables included.

CONCLUSIONS

Our study shows an increasing prevalence of HIV-1 and a decreasing prevalence of HIV-2 in Guinea-Bissau. The incidence of HIV-2 declined significantly whereas the incidence of HIV-1 was relatively stable over the study period. No protective effect of HIV-2 against subsequent HIV-1 infection was observed, instead HIV-2-positive subjects had a tendency towards higher risk of acquiring HIV-1 infection compared with seronegative subjects.

Oxidative inactivation of surfactants

Reactive oxygen species (ROS) may play an important role in the chronic pulmonary morbidity of preterm infants. We therefore studied the magnitude and mechanisms of oxidative inactivation of a natural lung surfactant (NLS) and of two surfactants used for treatment of respiratory distress syndrome, beractant and KL4 surfactant (KL4). Incubation with Fenton reagents, 2-4 mM peroxynitrite (ONOO-) or 0.5 mM hypochlorous acid (OCl-), resulted in an increased minimum surface tension (MST) of all surfactants; the order of effect on MST was beractant > KL4 > NLS. After incubation with Fenton reagents, NLS contained a higher concentration of conjugated dienes (p < 0.01) but lower concentration of malondialdehyde (p < 0.001) than beractant. Protein carbonyl concentrations after treatment with Fenton reagents were higher in NLS and KL4 than in beractant (p < 0. 05). Surface area cycling for 24 h with 2 mM ONOO- or 0.5 mM OCl- caused both beractant and KL4 to increase the proportion of light subtypes from 8-10% to 26-29%; with Fenton reagents, there was disappearance of the light subtype and formation of ultraheavy subtype 74-91% with poor MST. Natural and therapeutic surfactants differ markedly in their sensitivity to ROS, which may be important for surfactants in therapeutic use because oxidative inactivation may limit their effect. Oxidation of natural surfactant may result in reduced function and contribute to chronic lung disease.

Electrodermal Responsiveness and Negative Symptoms in Brain Injured Patients

Abstract Electrodermal non-responsiveness has been associated with negative symptoms, especially among schizophrenic patients. The aim of this study was to examine how electrodermal non-response, defined as failure to elicit a skin conductance orienting response to a neutral auditory stimulus, was related to negative symptoms in patients with acquired brain injury. Sixty-four brain injured patients were assessed for apathy, lack of initiative, and emotional indifference. We found that EDA non-responders displayed significantly higher scores on rating scales used to assess apathy and related negative symptoms compared to EDA responders. No such differences were found regarding depressed mood/emotional distress or vegetative symptoms of depression. This difference could not be attributed to neurological etiology nor to localization of lesion. These findings, resembling psychophysiological findings in schizophrenia, indicate that EDA non-response is associated with apathy and related negative symptoms also in brain injured patients. This may also enable a better differentiation between negative symptoms of organic origin and emotional changes related to psychogenic factors after acquired brain damage.

Apathy and depressed mood in acquired brain damage: relationship to lesion localization and psychophysiological reactivity

BACKGROUND

Apathy is a frequent neurobehavioural sequel in patients with acquired brain damage and it may seriously affect outcome of rehabilitation.

METHODS

Patients with traumatic brain injury, cerebrovascular insults and hypoxic brain injury, categorized into four lesion localization groups: left hemisphere damage (LHD); right hemisphere damage (RHD); bilateral hemispheric damage (BHD); and subcortical damage (SCD) were assessed with the Apathy Evaluation Scale (AES) and Montgomery and Asberg Depression Rating Scale (MADRS). Heart rate and electrodermal activity were recorded in an experimental situation that exposed the patients to mental stressors in order to measure psychophysiological reactivity.

RESULTS

Significant differences in level of apathy were found between diagnostic groups as well as between localization subgroups. SCD and RHD patients displayed most apathy. Factor analysis of MADRS revealed a three-factor solution; depressed mood, somatic symptoms and negative symptoms. Apathy was significantly correlated with negative symptoms in all localization subgroups, except among the BHD patients. Apathy was not correlated with depressed mood or somatic symptoms. Moreover, apathy was significantly correlated with heart rate reactivity, but not with electrodermal reactivity.

CONCLUSION

Apathy is common, its severity depending on diagnosis and localization of lesion. Apathy and depression in brain damaged patients share common features, but may be differentiated. The significant relationship between apathy and heart rate may provide a psychophysiological correlation of the disengagement, lack of interest and absence of emotional responsivity typically seen in apathy. The results have implications for the theoretical understanding of apathy and related negative symptoms, and for rehabilitation practice.

17Beta-hydroxysteroid dehydrogenase 3 deficiency in women

In genetic males, mutation of the 17beta-hydroxysteroid dehydrogenase 3 (17HSD3)gene that is normally expressed in the testes impairs testosterone formation and causes development of male pseudohermaphroditism. We have ascertained seven women who are sisters of men with 17HSD3 deficiency and who are either homozygotes or compound heterozygotes for the same mutations as their affected brothers. Our findings confirm the concept that women with such mutations are asymptomatic.

Changes in leptin concentration during the early postnatal period: adjustment to extrauterine life?

There are substantial alterations in fuel homeostasis immediately after birth. Leptin is a putative regulator of energy metabolism. Consequently, the aim of this study was to examine whether there are changes in circulating leptin concentrations during the early postnatal period. Umbilical cord mixed blood samples were taken at delivery, and a venous blood sample was obtained at 3 d of age from 38 healthy newborn infants (20 male, 18 female; gestational age 36.3 to 41.9 wk) for analysis of leptin concentration with radioimmunoassay. Cord plasma leptin concentration was 9.7+/-5.2 microg/L (mean+/-SD), with no gender difference between male (8.6+/-4.6 microg/L) and female (10.9+/-5.6 microg/L) infants. In male newborns, cord plasma leptin concentration correlated with arm circumference (r = 0.48, p < 0.05), and in female newborns with body mass index (r = 0.62, p < 0.01), thickness of the s.c. fat (r = 0.54, p < 0.05), and arm circumference (r = 0.72, p < 0.01). By the third postnatal day, plasma leptin decreased similarly in male (to 1.8+/-0.4 microg/L, p < 0.001) and female (to 2.3+/-0.8 microg/L, p < 0.001) infants, when there was a significant gender difference in leptin levels (p = 0.01). At 3 d of age, plasma leptin correlated with weight (r = 0.49, p < 0.05) and arm circumference (r = 0.49, p < 0.05) in female but not in male newborns. In conclusion, 1) circulating leptin already correlates with adiposity at birth in female but not in male newborn infants and 2) leptin decreases markedly in both genders by the third postnatal day, and the gender difference with higher leptin levels in females develops by that time. Thus, the postnatal decrease in plasma leptin concentration may be a physiologically feasible adaptation to profound alterations in fuel homeostasis during the first days of extrauterine life.

The serum transferrin receptor concentration in seven fetuses with hemolytic disease

Six pregnant women who received intrauterine transfusions and their seven fetuses were followed during gestation. Hemoglobin concentration, hematocrit value, serum ferritin, and serum transferrin receptor (TfR) concentrations were measured. In the fetal samples, there was a tendency for the TfR concentration to decrease during gestation and after the intrauterine transfusions. Serum TfR values varied between 0.7 and 5.2 mg/L, which is near the postnatal level measured in premature infants. On the contrary, one would have expected to find highly elevated values due to the active fetal erythropoiesis. The fetal regulation of TfR production may differ from that described postnatally.

Deficient 17beta-hydroxysteroid dehydrogenase type 2 expression in endometriosis: failure to metabolize 17beta-estradiol

Aberrant aromatase expression in stromal cells of endometriosis gives rise to conversion of circulating androstenedione to estrone in this tissue, whereas aromatase expression is absent in the eutopic endometrium. In this study, we initially demonstrated by Northern blotting transcripts of the reductive 17beta-hydroxysteroid dehydrogenase (17betaHSD) type 1, which catalyzes the conversion of estrone to 17beta-estradiol, in both eutopic endometrium and endometriosis. Thus, it follows that the product of the aromatase reaction, namely estrone, that is weakly estrogenic can be converted to the potent estrogen, 17beta-estradiol, in endometriotic tissues. It was previously demonstrated that progesterone stimulates the inactivation of 17beta-estradiol through conversion to estrone in eutopic endometrial epithelial cells. Subsequently, 17betaHSD type 2 was shown to catalyze this reaction, and its transcripts were detected in the epithelial cell component of the eutopic endometrium in secretory phase. Because 17beta-estradiol plays a critical role in the development and growth of endometriosis, we studied 17betaHSD-2 expression in endometriotic tissues and eutopic endometrium. We demonstrated, by Northern blotting, 17betaHSD-2 messenger ribonucleic acid (RNA) in all RNA samples of secretory eutopic endometrium (n=12) but not in secretory samples of endometriotic lesions (n=10), including paired samples of endometrium and endometriosis obtained simultaneously from eight patients. This messenger RNA was not detectable in any samples of proliferative eutopic endometrium or endometriosis (n=4) as expected. Next, we confirmed these findings by demonstration of immunoreactive 17betaHSD-2 in epithelial cells of secretory eutopic endometrium in 11 of 13 samples employing a monoclonal antibody against 17betaHSD-2, whereas 17betaHSD-2 was absent in paired secretory endometriotic tissues (n=4). Proliferative eutopic endometrial (n=8) and endometriotic (n=4) tissues were both negative for immunoreactive 17betaHSD-2, except for barely detectable levels in 1 eutopic endometrial sample. Finally, we sought to determine whether deficient 17betaHSD-2 expression in endometriotic tissues is due to impaired progesterone action in endometriosis. We determined by immunohistochemistry the expression of progesterone and estrogen receptors in these paired samples of secretory (n=4) and proliferative (n=4) eutopic endometrium and endometriosis, and no differences could be demonstrated. In conclusion, inactivation of 17beta-estradiol is impaired in endometriotic tissues due to deficient expression of 17betaHSD-2, which is normally expressed in eutopic endometrium in response to progesterone. The lack of 17betaHSD-2 expression in endometriosis is not due to alterations in the levels of immunoreactive progesterone or estrogen receptors in this tissue and may be related to an inhibitory aberration in the signaling pathway that regulates 17betaHSD-2 expression.

Clinical features, immunological changes and mortality in a cohort of HIV-2-infected individuals in Bissau, Guinea-Bissau

Clinical symptoms and immunological changes associated with HIV-2 infection were studied in a cohort of police officers in Guinea-Bissau. HIV-related symptoms were classified according to the WHO clinical staging system. The inclusion period was from January 1990 to January 1997, and among 2637 subjects included (90.7%M, 9.3%F), the prevalence of HIV-1, HIV-2 and dual reactivity to both HIV-1 and HIV-2 was 0.9%, 9.7% and 0.5%, respectively. Weight loss > 10%, diarrhoea or fever > 1 month, generalized lymphadenopathy and generalized pruritic dermatitis were significantly associated with HIV-2 infection as well as suppression of CD4 cells as compared with HIV-negative controls. Females had significantly higher CD4 cell counts than males, both among HIV-negative and HIV-2-positive asymptomatic individuals. The mortality rates/100 person-years (p.y.) were 0.4 in HIV-negative and 2.6 in HIV-2-positive subjects, giving an age-adjusted mortality rate ratio of 6.6 (95% CI, 4.0-10.9; p < 0.001). The mortality rate among HIV-2-infected individuals varied considerably in different stages of the WHO clinical staging system; 1.7 and 8.0/100 p.y. in stage 1 and 3, respectively.

Bronchoalveolar lavage with KL4-surfactant in models of meconium aspiration syndrome

As a model of the meconium aspiration syndrome (MAS) of human infants, adult rabbits and newborn rhesus monkeys received intratracheal instillation of human meconium to induce pulmonary injury. Injured rabbits were ventilated with 100% O2 and divided into four treatment groups, receiving: 1) bronchoalveolar lavages (BAL) with dilute KL4-Surfactant; 2) lavages with equal volumes of sterile saline; 3) a single intratracheal bolus of KL4-Surfactant, 100 mg/kg; and 4) no treatment. The untreated rabbits developed atelectasis, a fall in pressure-volume levels and in partial pressure of O2 in arterial blood (PaO2) from approximately 500 to < 100 mm Hg, and severe pulmonary inflammation between 3 and 5 h after instillation of meconium. Rabbits treated by BAL with dilute KL4-Surfactant showed rapid and sustained recovery of PaO2 to approximately 300 mm Hg within minutes, a return toward normal pressure-volume levels, and diminished inflammation. Rabbits receiving BAL with saline failed to show recovery, and rabbits treated with a bolus of surfactant intratracheally exhibited a transient response by 1-2 h after treatment, but then returned to the initial atelectatic state. Newborn rhesus monkeys, after receiving human meconium intratracheally before the first breath, developed severe loss of pulmonary function. Treatment of these monkeys 1-5 h after birth with BAL with dilute KL4-Surfactant produced clearing of chest radiographs and a rapid improvement in pulmonary function with ratios of partial pressure of O2 in arterial blood to the fraction of O2 in the inspired air rising into the normal range where they remained through the 20-h period of study. The studies indicate that pulmonary function in two models of severe meconium injury respond rapidly to BAL with dilute KL4-Surfactant.

17Beta-hydroxysteroid dehydrogenase types 1 and 2 in human placenta: an immunohistochemical study with correlation to placental development

In estrogen metabolism, the enzymatic properties of the 17beta-hydroxysteroid dehydrogenase (17betaHSD) isozymes play very important roles in steroid hormone metabolism in various tissues, including the placenta. 17betaHSD type 1 catalyzes primarily the reduction of estrone (E1) to estradiol (E2), whereas 17betaHSD type 2 catalyzes primarily the oxidation of E2 to E1. In this study, we examined immunohistochemical localization of 17betaHSD types 1 and 2 in human placenta (31 cases) ranging from 4-40 weeks gestation. The immunoreactivity of 17betaHSD type 1 was exclusively detected in syncytiotrophoblast from 4 weeks gestation to term placenta. Immunoreactivity of 17betaHSD type 2 first appeared in endothelial cells of intravillous vessels at 12 weeks gestation, and the number of 17betaHSD type 2-positive endothelial cells markedly increased up to 19 weeks, then reached a plateau. We quantitatively evaluated the 17betaHSD type 2-positive endothelial cells in chorionic villi and determined the ratio of 17betaHSD type 2-positive endothelial cells using immunohistochemistry of CD34, an endothelial antigen, in serial mirror tissue sections and subsequent image analysis using CAS 200. CD34 was detected from 4 weeks gestation, and its positive areas continued to increase toward term. The 17betaHSD type 2-positive area per CD34-positive area markedly increased from 13 weeks gestation and reached a plateau at 19 weeks gestation, in which almost all endothelial cells were positive for 17betaHSD type 2. 17BetaHSD type 2, therefore, is considered to prevent the passage of excessive estrogens into the fetal circulation at endothelial cells of the intravillous fetal capillaries by catalyzing the inactivation ofE2 to E1.

Declining HIV-2 prevalence and incidence among men in a community study from Guinea-Bissau

OBJECTIVE

To assess the present level of HIV-2 infection in an adult population in Bissau and to evaluate sex and age-specific changes in HIV-2 prevalence and incidence between 1987 and 1996.

DESIGN AND METHODS

Sex and age-specific changes in HIV-2 prevalence were evaluated comparing a survey from 1987 in a sample of 100 houses with a survey performed in 1996 in an independent sample of 212 houses from the same study area. HIV-2 incidence rates were examined in an adult population (age > or = 15 years) from 100 randomly selected houses followed with four consecutive HIV serosurveys from 1987 to 1996.

RESULTS

The HIV-2 prevalence in 1996 was 6.8% (men, 4.7%; women, 8.4%). Compared with the 1987 survey there was a significant decrease in prevalence among men [age-adjusted relative risk (RR), 0.50; 95% confidence interval (CI), 0.31-0.83], whereas it remained unchanged in women (RR, 1.00; 95% CI, 0.67-1.48). The male-to-female RR decreased from 0.99 (95% CI, 0.61-1.61) in 1987 to 0.51 (95% CI, 0.34-0.76) in 1996. The overall annual incidence rate was 0.54 per 100 person-years of observation (PYO), being higher in women (0.72 per 100 PYO) than in men (0.31 per 100 PYO). With the observation time divided into an early and a late period, there was a decrease in incidence with time among men (0.66 to 0.00 per 100 PYO), but no major change among women (0.59 to 0.85 per 100 PYO). The two trends differed significantly (P = 0.03). We observed a higher annual incidence rate amongst older women aged > 44 years (1.77 per 100 PYO) than among younger women (0.55 per 100 PYO; P = 0.05).

CONCLUSION

There are no signs of an epidemic spread of HIV-2 in Bissau even though the HIV-1 prevalence is increasing rapidly. A significant reduction in the male HIV-2 prevalence and incidence rates has resulted in a major shift in the pattern of spread of HIV-2, from being equally distributed to being predominantly a female infection. Currently, older women in particular seem to have a high risk of getting infected.

17beta-hydroxysteroid dehydrogenases: physiological roles in health and disease

Androgens and estrogens play crucial roles in the growth and development of sex organs. Interconversion of these hormones between biologically active and inactive forms is catalyzed by 17beta-hydroxysteroid dehydrogenase (17beta-HSD) isozymes. Aberrations in the regulation or expression of the various 17beta-HSD isoforms has been implicated in the genesis/progression of hormonally dependent cancers of various tissues, including ovary, breast and prostate; in the predisposition of women with upper body obesity to several types of diseases, such as non-insulin dependent diabetes mellitus; and in the abnormal development of sexually ambiguous individuals, as seen in 17beta-HSD-deficient male pseudohermaphrodites. Of the five known 17beta-HSD isozymes, deleterious mutations in the type 3 isoform were found to give rise to male pseudohermaphroditism. The 16 mutations characterized to date include 12 missense mutations, three splice junction mutations, and one small deletion that results in a downstream premature stop codon. 17beta-HSD has also been studied in other species. The most notable species difference observed is the placental expression in humans of the 17beta-HSD type 1 isoform.

Deleterious missense mutations and silent polymorphism in the human 17beta-hydroxysteroid dehydrogenase 3 gene (HSD17B3)

Isozymes of 17beta-hydroxysteroid dehydrogenase (17betaHSD) regulate levels of bioactive androgens and estrogens in a variety of tissues. For example, the 17betaHSD type 3 isozyme catalyzes the conversion of the inactive C19-steroid androstenedione to the biologically active androgen, testosterone, in the testis. Testosterone is essential for the correct development of male internal and external genitalia; hence, deleterious mutations in the HSD17B3 gene give rise to a rare form of male pseudohermaphroditism termed 17betaHSD deficiency. Here, 2 additional missense mutations in the HSD17B3 gene in subjects with 17betaHSD deficiency are described. One mutation (A56T) impairs enzyme function by affecting NADPH cofactor binding. A second mutation (N130S) led to complete loss of enzyme activity. Also, a single base pair polymorphism in exon 11 of the HSD17B3 gene is described. The polymorphic A allele encodes a protein with a serine rather than a glycine at position 289 (GGT --> AGT). The frequency of the G allele (Gly) was 0.94, and that of the A allele (Ser) was 0.06. No difference in the frequencies of the G and A alleles was detected in 32 apparently normal women and 46 women with polycystic ovary syndrome. Enzymes bearing either glycine or serine at this position have similar substrate specificities and kinetic constants. The current findings boost to 16 the number of mutations in the HSD17B3 gene that impair testosterone synthesis and cause male pseudohermaphroditism, and add 1 apparently silent polymorphism to this tally.

Mechanisms of diarrhoea in myotonic dystrophy

BACKGROUND

Gastrointestinal (GI) symptoms are common in myotonic dystrophy (MD). Diarrhoea is one of the more disabling of these GI complaints. The mechanisms behind diarrhoea in MD have not previously been investigated systematically.

OBJECTIVE

To elucidate the mechanisms behind diarrhoea in MD.

METHODS

Twenty patients with MD and suffering from diarrhoea were investigated in order to detect malabsorption (blood tests and faecal fat excretion) and bile acid malabsorption ([75Se]selenahomocholic acid-taurine (SeHCAT) retention) and to study intestinal morphology (duodenal and rectal biopsies).

RESULTS

Two patients had deficiency of folic acid and four showed reduced levels of pancreatic isoamylase, but none of them had steatorrhoea. Two out of eight patients had abnormal bile acid breath tests with normal SeHCAT, indicating small bowel bacterial overgrowth and 12 displayed reduced SeHCAT retention. Duodenal biopsies were normal in eight patients and five out of nine rectal biopsies displayed slight inflammation.

CONCLUSIONS

A possible mechanism of diarrhoea in MD could be identified in most of the patients. Bile acid malabsorption seems to be a frequent cause and can be treated successfully.

Heart rate and skin conductance reactivity to brief psychological stress in brain-injured patients

Autonomic reactivity in response to two mentally challenging tasks was studied in 74 patients with traumatic brain injury (TBI; n=33), cerebrovascular insults (CVA; n=27), and hypoxic brain damage (n = 14). Heart rate, skin conductance level, and number of spontaneous skin conductance responses were recorded during baseline and two problem-solving stress conditions consisting of Raven progressive matrices and mental arithmetic. CVA and TBI patients with focal right hemisphere injury showed significantly reduced stress reactivity compared to patients with focal left hemisphere injury. This right-left hemisphere difference was maintained when controlled for diagnosis, gender, sex, age, and stressor task performance and involvement. The results indicate that lateralization of lesion rather than diagnosis or etiology is the critical factor in autonomic stress hyporeactivity in brain-injured patients. The results are discussed in relation to brain lateralization of autonomic reactivity and possible clinical consequences of autonomic hyporeactivity for rehabilitation of patients with acquired brain injury.

Screening for human T cell leukaemia/lymphoma virus among blood donors in Sweden: cost effectiveness analysis

OBJECTIVE

To analyse the cost effectiveness of a national programme to screen blood donors for infection with the human T cell leukaemia/lymphoma virus.

DESIGN

Three models for calculating the costs and benefits of screening were developed. The first model analysed the cost of continuously testing all donations; the second analysed the cost of initially testing new blood donors and then retesting them after five years; the third analysed the cost of testing donors only at the time of their first donation. Patients who had received blood components from donors confirmed to be infected with the virus were offered testing.

SETTING

Sweden.

MAIN OUTCOME MEASURES

Prevalence of infection with the virus among blood donors, the risk of transmission of the virus, screening costs, and the outcome of infection.

RESULTS

648 497 donations were tested for the virus; 1625 samples tested positive by enzyme linked immunosorbent assay. 6 were confirmed positive by western blotting. The prevalence of infection with the virus was 2/100 000 donors. 35 patients who had received blood infected with the virus were tested; 3 were positive. The cost of testing every donation was calculated to be $3.02m (1.88m pounds); this is 18 times higher than the cost of testing new donors only, and only 1 additional positive donor would be discovered in 7 years. Regardless of the model used, screening was estimated to prevent only 1 death every 200 years at a minimum cost of $36m (22.5m pounds).

CONCLUSION

Based on these estimates the Swedish National Board of Health and Welfare decided that only new blood donors would be screened for infection with the virus.

Circulating xanthine oxidase and neutrophil activation during human liver transplantation

BACKGROUND & AIMS

Oxygen free radicals, generated by xanthine oxidase (XO) and activated leukocytes, are involved in reperfusion injury in experimental liver transplantation. The roles of XO and neutrophil activation during reperfusion in clinical liver transplantation were studied.

METHODS

In 10 patients undergoing liver transplantation, we assessed plasma concentrations of circulating XO by enzyme-linked immunosorbent assay (ELISA), the purine metabolites hypoxanthine, xanthine, and urate by high-performance liquid chromatography, lactoferrin by ELISA, and malondialdehyde fluorometrically up to 48 hours postoperatively.

RESULTS

During reperfusion after portal vein declamping, elevated plasma concentrations of XO (52.1 ng/mL [range, 8.0-440.1]), hypoxanthine (81.62 micromol/L [48.2-108.7]), xanthine (21.01 micromol/L [8.7-22.3]), and lactoferrin (532.6 ng/mL [370.4-1326.6]) were observed compared with the preoperative levels (0 ng/mL [0-12], 1.88 micromol/L [0.62-3.15], 0.95 micromol/L [0-0.41], and 164.3 ng/mL [73.7-334.1], respectively; all P < 0.05). No changes occurred in urate or malondialdehyde. After portal vein declamping, XO, hypoxanthine, and xanthine levels were substantially greater in the hepatic than portal vein (all P < 0.05). Marginal transhepatic differences occurred in lactoferrin.

CONCLUSIONS

Reperfusion during liver transplantation is associated with liberation of xanthine oxidase, hypoxanthine, and xanthine from the liver into the circulation. During reperfusion, intravascular neutrophil activation takes place in the hepatic circulation.