Prediction of future cardiovascular events by Framingham, SCORE and asCVD risk scores is less accurate in HIV-positive individuals from the HIV-HEART Study compared with the general population

OBJECTIVES

Cardiovascular diseases (CVDs) occur more often in people living with HIV (PLWH) than in the general population. It has been reported that CVD risk scores developed for the general population underestimate the CVD risk in PLWH. Performances of the Framingham Risk Score (FRS), the Systematic Coronary Risk Evaluation (SCORE) and the atherosclerotic cardiovascular disease (asCVD) risk score in PLWH were compared with the general population to quantify score-specific differences in risk prediction.

METHODS

HIV-positive outpatients from the HIV-HEART (HIVH) study (n = 567) were compared with participants from the population-based Heinz Nixdorf Recall (HNR) study (n ~ 4440) both recruited from the German Ruhr area. During a follow-up time of around 5 years, the associations between the FRS and incident CVD and peripheral artery disease (CVD_pAD), SCORE and coronary heart disease (CHD), and asCVD and incident CVD were examined using logistic regression. Score performances were assessed by comparing the areas under the curve (AUCs).

RESULTS

The mean ages were 52.9 ± 6.7 and 59.1 ± 7.7 years in the HIVH and HNR studies, respectively. There were fewer incident CVD events in the HNR study than in the HIVH study (CVD_pAD: 3.9% vs. 12.1%; CHD: 2.1% vs. 7.8%; CVD: 3.5% vs. 9.9%). Age- and sex-adjusted CVD risk was greater with increasing FRS, SCORE and asCVD in both cohorts, but the scores performed more accurately in the HNR than in HIVH study (AUCs FRS: 0.71 vs. 0.65; SCORE: 0.70 vs. 0.62; asCVD: 0.74 vs. 0.62).

CONCLUSIONS

Associations between risk scores and future CVD were observed in both cohorts, but the score performances were less reliable in PLWH than in the general population.

Reference curves for CD4 T-cell count response to combination antiretroviral therapy in HIV-1-infected treatment-naïve patients

OBJECTIVES

The aim of this work was to provide a reference for the CD4 T-cell count response in the early months after the initiation of combination antiretroviral therapy (cART) in HIV-1-infected patients.

METHODS

All patients in the Collaboration of Observational HIV Epidemiological Research Europe (COHERE) cohort who were aged ≥ 18 years and started cART for the first time between 1 January 2005 and 1 January 2010 and who had at least one available measurement of CD4 count and a viral load ≤ 50 HIV-1 RNA copies/mL at 6 months (± 3 months) after cART initiation were included in the study. Unadjusted and adjusted references curves and predictions were obtained using quantile regressions.

RESULTS

A total of 28 992 patients were included in the study. The median CD4 T-cell count at treatment initiation was 249 [interquartile range (IQR) 150, 336] cells/μL. The median observed CD4 counts at 6, 9 and 12 months were 382 (IQR 256, 515), 402 (IQR 274, 543) and 420 (IQR 293, 565) cells/μL. The two main factors explaining the variation of CD4 count at 6 months were AIDS stage and CD4 count at cART initiation. A CD4 count increase of ≥ 100 cells/mL is generally required in order that patients stay 'on track' (i.e. with a CD4 count at the same percentile as when they started), with slightly higher gains required for those starting with CD4 counts in the higher percentiles. Individual predictions adjusted for factors influencing CD4 count were more precise.

CONCLUSIONS

Reference curves aid the evaluation of the immune response early after antiretroviral therapy initiation that leads to viral control.

Substance use and sexual risk behaviour among HIV-positive men who have sex with men in specialized out-patient clinics

OBJECTIVES

Unprotected sexual intercourse between men who have sex with men (MSM) is the most common route of HIV infection in Germany. Approximately 70% of newly infected people are MSM. Substance use is a determinant of sexual risk behaviour in the general population, but also in the MSM subpopulation. There are only a few studies, from the USA, on the correlation between substance use and sexual risk behaviour in HIV-infected MSM in specialized care.

METHODS

In a German sample of 445 HIV-infected MSM treated in specialized out-patient clinics, the influence of substance use on sexual risk behaviour was investigated. Information was obtained from subjects using self-report questionnaires and a structured interview.

RESULTS

Recreational drug use was common. The prevalences of cannabis addiction (4.5%), harmful use of cannabis (4.3%) and harmful use of dissociative anaesthetics (0.4%) were higher than in the general German male population. A substantial proportion of patients reported unprotected insertive (32.9%) and receptive (34.6%) anal intercourse during the last 12 months. Use of cannabis, amyl nitrite, dissociative anaesthetics, cocaine, amphetamines and erectile dysfunction medication was significantly correlated with unprotected sexual contacts. Substance use in the context of sexual activity significantly increased sexual risk behaviour.

CONCLUSIONS

Substance use, especially in the context of sexual activity, should be taken into account when developing new prevention and intervention programmes aimed at reducing sexual risk behaviour in HIV-infected MSM currently in specialized care.

Simian virus 40 inhibits differentiation and maturation of rhesus macaque DC-SIGN(+) dendritic cells

Dendritic cells (DC) are the initiators and modulators of the immune responses. Some species of pathogenic microorganisms have developed immune evasion strategies by controlling antigen presentation function of DC. Simian virus 40 (SV40) is a DNA tumor virus of rhesus monkey origin. It can induce cell transformation and tumorigenesis in many vertebrate species, but often causes no visible effects and persists as a latent infection in rhesus monkeys under natural conditions. To investigate the interaction between SV40 and rhesus monkey DC, rhesus monkey peripheral blood monocyte-derived DC were induced using recombinant human Interleukin-4 (rhIL-4) and infective SV40, the phenotype and function of DC-specific intracellular adhesion molecule-3 grabbing nonintegrin (DC-SIGN)(+) DC were analyzed by flow cytometry (FCM) and mixed lymphocyte reaction (MLR). Results showed that SV40 can down-regulate the expression of CD83 and CD86 on DC and impair DC-induced activation of T cell proliferation. These findings suggest that SV40 might also cause immune suppression by influencing differentiation and maturation of DC.

German-Austrian recommendations for HIV-therapy in pregnancy and in HIV-exposed newborn - update 2005

In Germany during the last years about 200-250 HIV infected pregnant women delivered a baby each year, a number that is currently increasing. To determine the HIV-status early in pregnancy voluntary HIV-testing of all pregnant women is recommended in Germany and Austria as part of prenatal care. In those cases, where HIV infection was known during pregnancy, since 1995 the rate of vertical transmission of HIV was reduced to 1-2%. - This low transmission rate has been achieved by the combination of anti-retroviral therapy of pregnant women, caesarean section scheduled before onset of labour, anti-retroviral post exposition prophylaxis in the newborn and refraining from breast-feeding by the HIV infected mother. To keep pace with new results in research, approval of new anti-retroviral drugs and changes in the general treatment recommendations for HIV infected adults, in 1998, 2001 and 2003 an interdisciplinary consensus meeting was held. Gynaecologists, infectious disease specialists, paediatricians, pharmacologists, virologists and members of the German AIDS Hilfe (NGO) were participating in this conference to update the prevention strategies. A third update became necessary in 2005. The updating process was started in January 2005 and was terminated in September 2005. The guidelines provide new recommendations on the indication and the starting point for therapy in pregnancies without complications, drugs and drug combinations to be used preferably in these pregnancies and updated information on adverse effects of anti-retroviral drugs. Also the procedures for different scenarios and risk constellations in pregnancy have been specified again. With these current guidelines in Germany and Austria the low rate of vertical HIV-transmission should be further maintained.

Treatment of therapy-resistant Alopecia areata with fumaric acid esters

BACKGROUND

Alopecia areata is a cosmetically very disfiguring clinical picture and can be a great emotional burden to the patient, especially when persisting for a longer period of time.

PATIENTS AND METHODS

10 patients with an alopecia resistant to therapy were treated within the bounds of an open, non-placebo controlled pilot study with fumaric acid esters (FAE's, Fumaderm) for a period of six months and a maximum dose of 120 mg dimethylfumarate per day. The shortest space of time between persistent Alopecia areata and the start of the therapy with FAE was between six months and 17 years.

RESULTS

Six patients took benefit from the six months therapy with FAE. In three of them very good results could be observed, presenting an almost entire remission, one patient showed a good success with a focal remission. With two patients a mediocre to moderate outcome was observed with growth of partly diffuse spread or very thin hair. Four patients took no benefit from the FAE therapy at all.

CONCLUSIONS

FAE can be useful in the treatment of therapy-resistant Alopecia areata. This therapy approach should be validated in a multi-centre study.

Dilated cardiomyopathy in two adult human immunodeficiency positive (HIV+) patients possibly related to highly active antiretroviral therapy (HAART)

Human immunodeficiency virus (HIV) and acute immunodeficiency syndrome are known to be associated with cardiac involvement. In this respect, a relation between HIV and dilated cardiomyopathy has been described. Additionally, highly active antiretroviral therapy (HAART) may independently contribute to cardiac impairment. We here report two cases of severely reduced left ventricular function detected in the context of a recent standardized screening of 132 HIV+ individuals of the German heart failure network. Both patients presented in a poor overall condition and progressive exercise-induced dyspnea accompanied by edema or angina pectoris, respectively. Subsequent examinations revealed left bundle-branch blockade, ventricular arrhythmia, elevated serum BNP-levels as well as pathologic transthoracic echocardiography, left ventricular angiography, electron beam tomography and cardiac magnetic resonance imaging without significant coronary stenoses or immunohistological signs of an ongoing or prior myocarditis. Clinical signs of progressive chronic heart failure developed slowly but constantly following initiation of the HAART regimen. Patients were treated by an implantation of a biventricular implantable cardioverter defibrillator beside conventional conservative standard therapy followed by a significant improvement of clinical symptoms. Antiviral medication could be maintained in both patients. Taking all data into account, the diagnosis of a HAART-associated dilated cardiomyopathy could be assessed. Even though the pathogenesis of secondary heart failure after HAART is still object of investigation a mitochondrial impairment by antiviral drugs is thought to contribute the development of dilated cardiomyopathy. However, due to the coexistence of an eminent HIV infection, a direct effect of the HI virus itself can not be completely excluded.

Recommendations for the classification of HIV associated neuromanifestations in the German DRG system

HIV associated neuromanifestations are of growing importance in the in-patient treatment of HIV infected patients. In Germany, all in-patients have to be coded according to the ICD-10 classification and the German DRG-system. We present recommendations how to code the different primary and secondary neuromanifestations of HIV infection. These recommendations are based on the commentary of the German DRG procedures and are aimed to establish uniform coding of neuromanifestations.

[Aspects of rehabilitation in HIV and AIDS]

Medical treatment of HIV infection has changed dramatically since 1997. The uncontrollable threat became a chronic disease. On the other hand, many HIV-infected people suffer from high psychological distress and multiple physical complaints. Interaction in HIV prevention could transform into psychological counseling. Counselors should initiate rehabilitation measures and occupational reintegration by utilizing all legal possibilities for handicapped people. Patients and physicians, psychologists and social workers as well as self-help groups should initiate successful reintegration into the workforce and daily life; this could positively influence compliance behavior.

Cardiovascular risk factors and probability for cardiovascular events in HIV-infected patients - part III: age differences

OBJECTIVE

In recent years, concerns have been growing about an elevated rate of cardiovascular diseases in HIV-infected patients due to side effects of antiretroviral therapy. The present study analyses the cardiovascular risk profile and the probability of cardiovascular events with regard to the age of HIV-infected patients.

METHODS

Cardiovascular risk factors of 309 HIV-infected adults were analysed. Patients were divided into four groups: 18-30 years (group 1), 31-40 years (group 2), 41-50 years (group 3), > 50 years (group 4). Overall 10-years probability for cardiovascular events was evaluated by the Framingham algorithm.

RESULTS

Differences between the groups were detected in cardiovascular risk factors including changes in lipid- and glucose metabolism. Lipid values increased with elevated age, such as total cholesterol concentration (Mean +/- SEM in group 1 vs. group 4: 4.71 +/- 0.20 to 6.36 +/- 0.21 mmol/L, p < 0.05), LDL-cholesterol concentration (2.86 +/- 0.17 vs. 4.17 +/- 0.21 mmol/L, p < 0.05) and triglyceride concentration (1.56 +/- 0.14 vs. 3.48 +/- 0.40 mmol/L, p < 0.05). HDL-cholesterol concentration did not show a significant difference (1.15 +/- 0.03 mmol/L). Glucose concentration increased with elevated age in HIV-infected patients (5.28 +/- 0.19 vs. 6.46 +/- 0.24 mmHg, p < 0.05), but there was no significant difference in HbA1c - concentration, blood pressure and smoking rate between the groups. The overall 10-years probability for cardiovascular events was higher in group 1 (median: 1.9%) than in group 4 (20.5%; p < 0.01).

CONCLUSIONS

The risk of cardiovascular events is related to the age in HIV-infected patients. Therefore, an increased duration of life due to a more effective antiretroviral therapy will have a significant impact on the rate of cardiovascular events in this patient population. In the future, further increase of cardiovascular events in HIV-infected patients may be expected.

Cardiovascular risk factors and probability for cardiovascular events in HIV-infected patients: part I. Differences due to the acquisition of HIV-infection

OBJECTIVE

Due to side effects, such as hyperlipidaemia and insulin resistance, there is an increasing concern that antiretroviral drugs lead to an epidemic of cardiovascular diseases in HIV-infected patients. The present study characterizes the cardiovascular risk profile of HIV-infected individuals, due to the acquisition of HIV-infection.

METHODS

Cardiovascular risk factors of 309 HIV-infected adults (HIV-acquisition: 59.2% by homosexual contact (group 1), 28.5% by heterosexual contact (group 2), 9.1% by intravenous drug abuse (group 3) and 3.2% by blood transfusion (group 4)) were analysed. Overall 10-years probability for cardiovascular events was analysed by the Framingham algorithm.

RESULTS

Tobacco use was more common in group 1 subjects compared with group 2 subjects (67% vs. 52%; p<0.05). Additionally, group 1 subjects exhibited elevated total cholesterol (5.6 +/- 0.1 mmol/L vs. 4.8 +/- 0.3), LDL-cholesterol (3.6 +/- 0.1 mmol/L vs. 2.8 +/- 0.2) and triglyceride concentrations (3.2 +/- 0.3 mmol/L vs. 1.7 +/- 0.2) compared with group 3 (all p<0.05). No significant differences between the groups were detected in glucose metabolism. The overall 10-years probability for cardiovascular events was significantly higher in group 1 compared with group 2 and group 3 (12.2 +/- 0.8% vs. 6.6 +/- 0.9% and 7.9 +/- 1.6%, p<0.05).

CONCLUSIONS

The cardiovascular risk profile differs between subgroups of HIV-infected individuals, leading to significant higher probability of cardiovascular events in group 1 subjects. The risk of premature atherosclerosis by HIV-infected individuals and therapeutic options remains to be established.

Treatment of severe Candida infections in high-risk patients in Germany: consensus formed by a panel of interdisciplinary investigators

Now that modern medicine can provide increasing chances of cure to patients with formerly incurable disorders, therapy-related complications play the key role in outcome. Thus, among opportunistic infections, severe candidiasis remains a challenge. A multidisciplinary panel of 20 investigators was formed to find a consensus on antifungal strategies for various underlying conditions in neutropenic and non-neutropenic patients. To record their preferences, the investigators used an anonymous voting system. Among antifungal agents, fluconazole emerged as the major alternative to the classic amphotericin B, being therapeutically at least equivalent but clearly less toxic. Factors that restrict the use of fluconazole include pretreatment with azoles, involvement of resistant species like Candida krusei, and an inability to exclude aspergillosis. Flucytosine can be reasonably combined with both amphotericin B and fluconazole. Within the limited antifungal armamentarium, amphotericin B lipid formulations and itraconazole also appear useful and require further investigation. The general consensus of the group is that antifungal agents should be administered at sufficient dosages, rather early, and often empirically.

Pneumocystis carinii pneumonia in the Federal Republic of Germany in the era of changing antiretroviral therapy - IDKF 13 -. German AIDS Study Group (GASG/IdKF)

BACKGROUND

Pneumocystis carinii pneumonia (PCP) is one of the most common AIDS defining diagnoses.

METHODS

In a prospective observational trial all cases of Pneumocystis carinii pneumonia (PCP) were evaluated. Patients with and without PCP-prophylaxis were compared for symptoms, efficacy, side effects and mortality at week 4 and 26.

RESULTS

293 patients developed a PCP episode. Patients with no prophylaxis had a significant lower CD4 cell count and a more severe clinical status at time of diagnosis. This was pronounced in the group with first positive HIV test at time of diagnosis. There was no difference in the rate of successful treatment between both groups. At week four a tendency to a better survival in the group with prophylaxis was observed, however this changed to a trend to a better survival at week 26 for the group without prophylaxis.

CONCLUSION

Even in the era of highly active antiretroviral treatment many patients present with PCP. Nearly 60% of patients presented without antiretroviral treatment or PCP-prophylaxis. Nearly 25% of all patients had their first HIV-test at time of PCP diagnosis.

German-Austrian Guidelines for HIV-therapy during pregnancy--status: May/June 1998--common statement of the Deutsche AIDS-Gesellschaft (DAIG) and the Osterreichische AIDS-Gesellschaft (OAG)

The same guidelines are valid for HIV-infected women during pregnancy as for HIV-infected adults. The only modification of these guidelines necessary is that treatment is indicated in clinically asymptomatic pregnant patients when the T-helper cell count is <250-400/microl. Initial therapy is a 3-drug combination including two nucleoside reverse transcriptase inhibitors (NRTI) and one protease inhibitor (PI) or one non-nucleoside reverse transcriptase inhibitor (NNRTI). Since the teratogenicity of PI and NNRTI is unclear, a virologically weaker two-drug combination consisting of 2 NRTIs can be resorted to. When therapy is pending, embryonal toxicological factors require a decision to be made in the first trimester of pregnancy as to whether a therapy pause of maximally 3 months is medically tenable for the pregnant woman. The decision should be adjusted to the risk and reached in each individual case after consulting with the future mother. The same substances can be administered when antiretroviral medication is started again, since it is unlikely that resistance will develop. To reduce the risk of vertical transmission, the following prophylactic regimen is recommended during delivery: 1) zidovudine treatment of the mother after completion of the 32nd week of pregnancy (32 + 0) at a dosage of 5 x 100 mg/day or 2 x 250 mg/day orally; if necessary, in addition to the ongoing antiretroviral therapy. 2) first-option cesarean section along with preparation of fetal membrane before onset of labor in the 36th completed week of pregnancy (36 + 0). 3) preoperative intravenous zidovudine therapy (2 mg/kg body weight). 4) postnatal zidovudine therapy of the child for 10 days intravenously (1.3 mg/kg every 6 hours) or 2-6 weeks orally (2 mg/kg every 6 hours). In exceptional obstetric cases, e.g., premature labor, premature rupture of the membranes, amniotic infection syndrome, or multiple pregnancy, cesarean section is also the preferred mode of delivery. However, the decision must be made on the basis of obstetric concerns. If prophylaxis to prevent transmission has been incomplete, at least intrapartum and postnatal treatment should be given. If the HIV status of the mother is unclear, it must be ascertained in order to administer a prophylaxis to prevent transmission if necessary. A competent consultation must always be offered, if appropriate also together with a relevant institution.

Clinical manifestations and therapies of AIDS associated tumors

We are giving an overview over the clinical features and different therapeutic options of HIV associated malignancies. There are three AIDS-defining malignancies: - Kaposi's sarcoma - Non-Hodgkin's lymphoma (NHL) - cervical cancer. In Kaposi sarcoma there is a broad therapeutic spectrum from cryotherapy to systemic chemotherapy depending on the site and stage of the Kaposi sarcoma. In NHL early therapeutic intervention is necessary because of the fast progress of the tumor. The cervical cancer in HIV-infected women seems to be more aggressive than in non-infected and also needs early therapeutic intervention. Many other tumors seem to occur more frequently in patients with HIV infection: anorectal cancer, malignant testicular tumors, lung cancer, Hodgkin's lymphoma, basal cell carcinoma, squamous cell carcinoma, and even malignant melanoma. The cancer incidence in HIV-patients seems to be higher among nonblacks. Most of the immunodeficiency associated tumors are virus induced and they are accompanied by a persistent viral infection, including HHV-8 in Kaposi's sarcoma; Epstein Barr virus (EBV) in NHL; and human papillomavirus (HPV) in cervical cancer. But there are also types of virus induced tumors which are not frequently associated with HIV-infection like the primary hepatocellular carcinoma in patients with hepatitis B virus infection.

Signalling properties of lysophosphatidic acid in primary human skin fibroblasts: role of pertussis toxin-sensitive GTP-binding proteins

We have investigated the signalling properties of the naturally occurring intercellular signalling molecule lysophosphatidic acid (LPA) in primary human skin fibroblasts. LPA stimulated phospholipase C activity resulting in the formation of inositol 1,4,5-trisphosphate (IP3) which was accompanied by a concentration-dependent increase in intracellular calcium concentration ([Ca2+]i). The increase in [Ca2+]i was subject to homologous desensitisation but not to heterologous desensitisation by sphingosine-1-phosphate. The half-maximal effect of LPA on the rise in [Ca2+]i was attained at 7-20 nM. IP3 formation and Ca2+ mobilisation were highly pertussis toxin (PTX)-sensitive (100% and 75%, respectively). LPA also inhibited forskolin-stimulated formation of cAMP, which was partially reversed (51%) when fibroblasts were pretreated with PTX. To directly test the involvement of guanine nucleotide-binding regulatory proteins (G proteins), LPA-induced binding of the stable GTP analogue GTP gamma S was measured. LPA induced an increase in GTP gamma S binding, which was completely inhibited by PTX, implicating the involvement of Gi-type G proteins in LPA signalling. Furthermore, LPA increased DNA synthesis and cell proliferation. Finally, LPA induced the migration of human skin fibroblasts, which in conjunction with the stimulation of cell growth strengthens the presumed involvement of LPA in wound healing and tissue regeneration. Both effects (cell growth and migration) were almost completely PTX-sensitive. Overall, these investigations in primary cultures of human skin fibroblasts confirm and extend our knowledge about LPA signalling, suggesting a pivotal role of receptor coupled activation of Gi-type proteins at least in this cell type.

Selectively enhanced cellular signaling by Gi proteins in essential hypertension. G alpha i2, G alpha i3, G beta 1, and G beta 2 are not mutated

Recent studies have shown an enhanced signaling capacity of receptors coupled to pertussis toxin (PTX)-sensitive guanine nucleotide-binding proteins (G proteins) in immortalized B lymphoblasts from patients with essential hypertension. In the present study, we analyzed (1) whether such alterations would also be expressed in nontransformed cells of these individuals and (2) whether other G protein-mediated signaling pathways were also altered. Therefore, we established primary cultures of skin fibroblasts from previously characterized normotensive and hypertensive individuals (NT and HT cells, respectively). [Ca2+]i rises induced by lyso-phosphatidic acid (LPA), thrombin, and sphingosine-1-phosphate as well as the formation of inositol 1,4,5-trisphosphate and [3H]thymidine incorporation evoked by LPA were PTX sensitive and enhanced twofold in HT fibroblasts. In contrast, cellular responses induced by bradykinin, endothelin-1, and angiotensin II (all PTX insensitive) were similar in NT and HT cells. Formation of cAMP induced by stimulation of Gs with isoproterenol was identical in NT and HT cells. Western blot analysis yielded no evidence for an overexpression of G alpha i2, G alpha i3, G beta 2, and G beta 4. Furthermore, sequencing of cDNAs encoding for the ubiquitously expressed PTX-sensitive G protein subunits G alpha i2, G alpha i3, G beta 1, and G beta 2 from NT and HT cell lines yielded no evidence for mutations in these genes. Although the molecular mechanisms remain to be defined, these data support the concept of a selective enhancement of signal transduction via PTX-sensitive G proteins in essential hypertension.

Phenotypic analysis of bronchoalveolar lavage lymphocytes from acquired immunodeficiency patients with and without Pneumocystis carinii pneumonia

A study was performed to reveal possible differences in lymphocyte subpopulations from bronchoalveolar lavage (BAL) of acquired immunodeficiency patients with and without Pneumocystis carinii pneumonia. Forty-one consecutive human immunodeficiency virus-seropositive patients were studied. Pneumocystis carinii infection was detected in the BAL fluid from 18 patients. The BAL lymphocyte subpopulations were determined by surface marker analysis with the immunoperoxidase slide assay. No significant differences in the percentage of CD4+ and CD8+ lymphocytes were found between the two groups. The percentage of CD57+ natural killer (NK) cells was significantly higher in the Pneumocystis carinii-negative group than in the -positive group. Since NK cells protect from microbial infections, it is conceivable that the loss of CD57+ NK cells may be one of the phenomena leading to the immunodeficiency state that underlies the pulmonary complications characteristic of the acquired immunodeficiency syndrome.

[Evoked potentials in neurologically asymptomatic persons during the early stages of HIV infection]

There are few reports on the relevance of evoked potentials in neurologically asymptomatic HIV seropositives. We studied 31 HIV infected males without AIDS or associated clinical neurological abnormalities. Visual evoked potentials by foveal checkerboard stimulation revealed a prolonged VEP latency in 37% of them. HIV seropositives with a pathologic VEP latency showed a significant reduction of their absolute numbers of peripheral blood T-helper cells. This increase of the mean VEP-latency was already significant in HIV seropositives with a T-helper cell count greater than 400/microliters. In 47% of the HIV seropositives the AEP peak I latency was prolonged in combination with a significant decrease of the AEP interpeak latency I-V suggesting endocochlear lesions at peripheral endings of the acoustic nerve or at the basal hair cells. HIV seropositives with a T-helper cell count less than 400/microliters revealed a significant prolongation of the mean AEP interpeak latency III-V indicating a central conduction defect in HIV-seropositives with an immune deficit. Somatosensory evoked potentials after median and tibial nerve stimulation were within the normal range. Since the VEP P100 latencies were significantly longer in HIV seropositives with a normal AEP peak I compared to those with prolonged AEP peak I latencies we postulate that there are different pathophysiological mechanisms underlying.

The effect of antipyrine and rifampin on the metabolism of diazepam

The elimination of diazepam and antipyrine and the urinary excretion of their metabolites were investigated in 21 healthy volunteers before and after 7 days of administration of antipyrine, 1200 mg, and rifampin, 600 or 1200 mg. After administration of antipyrine and rifampin in two doses, antipyrine total body clearance increased by 53% and 60% or 98%, respectively. The clearance to metabolite showed a preferential induction of the norantipyrine pathway with different proportions after antipyrine and rifampin; rifampin, 1200 mg, also enhanced the 4-hydroxyantipyrine pathway further. After antipyrine, diazepam total body clearance was increased by 102%, affecting all metabolic pathways to a similar extent. After rifampin in both doses, diazepam total body clearance rose equally to 300% and desmethyl- and 3-hydroxydiazepam metabolic clearance to 400%. Therefore rifampin preferentially affects norantipyrine or desmethyl- and 3-hydroxydiazepam metabolic formation, suggesting induction of different (iso)zymes of cytochrome P-450.

Relative and absolute numbers of human lymphocyte subpopulations. A comparison of immunofluorescence microscopy and flow cytometric methodologies with special reference to precision and reference values

Lymphocyte subpopulations were determined in blood samples from blood donors (40 women and 45 men) using immunofluorescence microscopy and flow cytometric methodologies. The study demonstrates the value of both methods for the enumeration of lymphocyte subpopulations. The advantages of employing an automated flow cytometer system are better precision and speed. The automated systems require a large initial technical and financial burden and are therefore probably destined to be reserved for the larger laboratory. There is a need for an adequate lymphocyte standard which shows little variation between aliquots and can be used for interlaboratory comparisons.