Clinical progression and virological failure on highly active antiretroviral therapy in HIV-1 patients: a prospective cohort study. Swiss HIV Cohort Study

BACKGROUND

The efficacy of highly active antiretroviral therapy (HAART) in suppression of HIV-1 is well documented. We investigated virological and clinical outcomes of HAART in routine practice.

METHODS

We analysed prospective data from the Swiss HIV Cohort Study on suppression of viral load and progression to AIDS or death in 2674 outpatients (median age 36 years, 27.3% women) who started HAART in 1995-98. Viral rebound was defined as two consecutive HIV-1-RNA measurements of more than 400 copies/mL. We analysed separately outcomes in patients with a history of antiretroviral treatment and in treatment-naïve patients.

FINDINGS

An estimated 90.7% of treatment-naïve patients reached undetectable viral load (<400 copies/mL) by 12 months. Among pretreated patients, estimates ranged from 70.3% treated with one new drug to 78.7% on three new drugs. 2 years after reaching undetectable concentrations, an estimated 20.1% of treatment-naïve patients and 35.7-40.1% of pretreated patients had viral rebound. At 30 months, an estimated 6.6% (95% CI 4.6-8.6) of patients who had maintained undetectable concentrations, 9.0% (5.5-12.5) who had viral rebound, and 20.1% (15.3-24.9) who had never reached undetectable concentrations developed AIDS or died. Compared with patients who maintained undetectable viral load, the adjusted relative hazard of AIDS or death was 1.00 (0.66-1.55) for patients with viral rebound, and 2.40 (1.72-3.33) for patients who failed to reach undetectable concentrations.

INTERPRETATION

The rate of virological failure of HAART was high among these patients, but the probability of clinical progression was low even in patients with viral rebound.

EAACI Molecular Allergology User's Guide

The availability of allergen molecules ('components') from several protein families has advanced our understanding of immunoglobulin E (IgE)-mediated responses and enabled 'component-resolved diagnosis' (CRD). The European Academy of Allergy and Clinical Immunology (EAACI) Molecular Allergology User's Guide (MAUG) provides comprehensive information on important allergens and describes the diagnostic options using CRD. Part A of the EAACI MAUG introduces allergen molecules, families, composition of extracts, databases, and diagnostic IgE, skin, and basophil tests. Singleplex and multiplex IgE assays with components improve both sensitivity for low-abundance allergens and analytical specificity; IgE to individual allergens can yield information on clinical risks and distinguish cross-reactivity from true primary sensitization. Part B discusses the clinical and molecular aspects of IgE-mediated allergies to foods (including nuts, seeds, legumes, fruits, vegetables, cereal grains, milk, egg, meat, fish, and shellfish), inhalants (pollen, mold spores, mites, and animal dander), and Hymenoptera venom. Diagnostic algorithms and short case histories provide useful information for the clinical workup of allergic individuals targeted for CRD. Part C covers protein families containing ubiquitous, highly cross-reactive panallergens from plant (lipid transfer proteins, polcalcins, PR-10, profilins) and animal sources (lipocalins, parvalbumins, serum albumins, tropomyosins) and explains their diagnostic and clinical utility. Part D lists 100 important allergen molecules. In conclusion, IgE-mediated reactions and allergic diseases, including allergic rhinoconjunctivitis, asthma, food reactions, and insect sting reactions, are discussed from a novel molecular perspective. The EAACI MAUG documents the rapid progression of molecular allergology from basic research to its integration into clinical practice, a quantum leap in the management of allergic patients.

Human microsporidial infections

Microsporidia are obligate intracellular spore-forming protozoal parasites belonging to the phylum Microspora. Their host range is extensive, including most invertebrates and all classes of vertebrates. More than 100 microsporidial genera and almost 1,000 species have now been identified. Five genera (Enterocytozoon spp., Encephalitozoon spp., Septata spp., Pleistophora sp., and Nosema spp.) and unclassified microsporidia (referred to by the collective term Microsporidium) have been associated with human disease, which appears to manifest primarily in immunocompromised persons. The clinical manifestations of microsporidiosis are diverse and include intestinal, pulmonary, ocular, muscular, and renal disease. Among persons not infected with human immunodeficiency virus, ten cases of microsporidiosis have been documented. In human immunodeficiency virus-infected patients, on the other hand, over 400 cases of microsporidiosis have been identified, the majority attributed to Enterocytozoon bieneusi, an important cause of chronic diarrhea and wasting. Diagnosis of microsporidiosis currently depends on morphological demonstration of the organisms themselves. Initial detection of microsporidia by light microscopic examination of tissue sections and of more readily obtainable specimens such as stool, duodenal aspirates, urine, sputum, nasal discharge, bronchoalveolar lavage fluid, and conjunctival smears is now becoming routine practice. Definitive species identification is made by using the specific fluorescein-tagged antibody (immunofluorescence) technique or electron microscopy. Treatment options are limited, but symptomatic improvement of Enterocytozoon bieneusi infection may be achieved with the anthelmintic-antiprotozoal drug albendazole. Preliminary observations suggest that Septata intestinalis and Encephalitozoon infections may be cured with albendazole. Progress is being made with respect to in vitro propagation of microsporidia, which is crucial for developing antimicrosporidial drugs. Furthermore, molecular techniques are being developed for diagnostic purposes, taxonomic classification, and analysis of phylogenetic relationships of microsporidia.

Improved light-microscopical detection of microsporidia spores in stool and duodenal aspirates. The Enteric Opportunistic Infections Working Group

BACKGROUND

The diagnosis of infection with Enterocytozoon bieneusi, a microsporidian organism that causes chronic diarrhea in patients infected with the human immunodeficiency virus (HIV), has depended on invasive procedures. We have developed a new method to detect microsporidia spores in feces and duodenal aspirates.

METHODS

Stool was obtained from four HIV-infected patients with biopsy-confirmed intestinal microsporidiosis. Slides prepared from unconcentrated, formalin-fixed stool specimens were stained with a new chromotrope-based technique and examined by light microscopy. Methods of stool concentration were also compared. The technique was then evaluated by examining 215 specimens from 134 HIV-infected persons with or without diarrhea. In addition, duodenal aspirates from 10 patients with unexplained chronic diarrhea were examined by light microscopy after staining according to the new and the traditional techniques.

RESULTS

E. bieneusi spores were found in all unconcentrated stool specimens from the four patients with microsporidiosis. The use of various methods of stool concentration did not improve the detection of microsporidia spores. In the prospective study, microsporidiosis was detected in samples from 6 of 27 patients with chronic diarrhea, but in none of those from 42 patients with acute diarrhea or 65 patients without diarrhea. The presence of microsporidia spores in stool specimens and duodenal aspirates allowed the successful prediction of the presence of microsporidia in small-bowel biopsy specimens from all four patients who subsequently underwent endoscopy.

CONCLUSIONS

E. bieneusi is an important cause of chronic diarrhea in HIV-infected persons. This new diagnostic technique serves as a practical, noninvasive means to detect microsporidia spores in stool specimens and is also applicable to the examination of duodenal aspirates.

AIDS-related opportunistic illnesses occurring after initiation of potent antiretroviral therapy: the Swiss HIV Cohort Study

CONTEXT

Acquired immunodeficiency syndrome-related opportunistic illnesses (Ols) continue to occur after initiation of potent antiretroviral therapy in patients with human immunodeficiency virus (HIV) infection. Risk factors for clinical progression to Ols during potent therapy are not well defined.

OBJECTIVE

To examine the incidence of and risk factors for Ols among patients treated with potent antiretroviral therapy in a population-based study.

DESIGN

The Swiss HIV Cohort Study, a prospective cohort study of adult HIV-infected persons.

SETTING

Seven study centers throughout Switzerland.

PATIENTS

A total of 2410 cohort study participants with a potential follow-up of at least 15 months after starting potent therapy between September 1995 and December 1997.

MAIN OUTCOME MEASURES

Disease-specific incidence of Ols during the 6 months preceding potent antiretroviral therapy and at 3 intervals after initiating therapy; risk factors for development of Ols during therapy.

RESULTS

Of the 2410 participants, 143 developed 186 Ols after initiation of potent antiretroviral therapy. Incidence of any OI decreased from 15.1 per 100 person-years in the 6 months before therapy to 7.7 in the first 3 months after starting treatment, 2.6 in the following 6 months, and 2.2 per 100 person-years between 9 and 15 months. Reductions in incidence ranged from 38% per month for Kaposi sarcoma (P<.001) to 5% per month for non-Hodgkin lymphoma (P = .31). Baseline CD4 cell count continued to predict the risk of disease progression after initiating potent therapy. Compared with CD4 cell counts above 200 x 10(6)/L, the hazard ratio for developing Ols was 2.5 (95% confidence interval [CI], 1.4-4.5) for counts between 51 and 200 x 10(6)/L and 5.8 (95% CI, 3.2-10.5) for counts below 51 x 10(6)/L at baseline. Independent of baseline CD4 cell count, a rise in CD4 cell count by 50 x 10(6)/L or more and undetectable HIV-1 RNA in plasma (<400 copies/mL) by 6 months reduced risk of subsequent events, with hazard ratios of 0.32 (95% CI, 0.20-0.52) and 0.39 (0.24-0.65), respectively.

CONCLUSIONS

Our data indicate that the risk of developing an OI for a person receiving potent antiretroviral therapy is highest during the initial months of therapy. Baseline CD4 cell count and immunologic and virologic response to treatment were strong predictors of disease progression in patients receiving potent therapy. Individuals with CD4 cell counts of 50 x 10(6)/L or below may need close clinical surveillance after initiation of potent therapy.

Decreasing mortality and changing patterns of causes of death in the Swiss HIV Cohort Study

BACKGROUND

Mortality among HIV-infected persons is decreasing, and causes of death are changing. Classification of deaths is hampered because of low autopsy rates, frequent deaths outside of hospitals, and shortcomings of International Statistical Classification of Diseases and Related Health Problems (ICD-10) coding.

METHODS

We studied mortality among Swiss HIV Cohort Study (SHCS) participants (1988-2010) and causes of death using the Coding Causes of Death in HIV (CoDe) protocol (2005-2009). Furthermore, we linked the SHCS data to the Swiss National Cohort (SNC) cause of death registry.

RESULTS

AIDS-related mortality peaked in 1992 [11.0/100 person-years (PY)] and decreased to 0.144/100 PY (2006); non-AIDS-related mortality ranged between 1.74 (1993) and 0.776/100 PY (2006); mortality of unknown cause ranged between 2.33 and 0.206/100 PY. From 2005 to 2009, 459 of 9053 participants (5.1%) died. Underlying causes of deaths were: non-AIDS malignancies [total, 85 (19%) of 446 deceased persons with known hepatitis C virus (HCV) status; HCV-negative persons, 59 (24%); HCV-coinfected persons, 26 (13%)]; AIDS [73 (16%); 50 (21%); 23 (11%)]; liver failure [67 (15%); 12 (5%); 55 (27%)]; non-AIDS infections [42 (9%); 13 (5%); 29 (14%)]; substance use [31 (7%); 9 (4%); 22 (11%)]; suicide [28 (6%); 17 (7%), 11 (6%)]; myocardial infarction [28 (6%); 24 (10%), 4 (2%)]. Characteristics of deceased persons differed in 2005 vs. 2009: median age (45 vs. 49 years, respectively); median CD4 count (257 vs. 321 cells/μL, respectively); the percentage of individuals who were antiretroviral therapy-naïve (13 vs. 5%, respectively); the percentage of deaths that were AIDS-related (23 vs. 9%, respectively); and the percentage of deaths from non-AIDS-related malignancies (13 vs. 24%, respectively). Concordance in the classification of deaths was 72% between CoDe and ICD-10 coding in the SHCS; and 60% between the SHCS and the SNC registry.

CONCLUSIONS

Mortality in HIV-positive persons decreased to 1.33/100 PY in 2010. Hepatitis B or C virus coinfections increased the risk of death. Between 2005 and 2009, 84% of deaths were non-AIDS-related. Causes of deaths varied according to data source and coding system.

Laparoscopic assisted live donor nephrectomy--a comparison with the open approach

Live donor renal transplantation provides significant advantages when compared with cadaveric donor renal transplantation in terms of improved patient and graft survival, a lower incidence of delayed function, and a shorter waiting time. Yet despite these advantages, live donors continue to be an under utilized source of kidneys for transplantation. Disincentives to live donation include the length of hospitalization, postoperative pain, cosmetic concerns, and the prolonged convalescence associated with the donor operation. In many instances minimally invasive video-assisted techniques have proven more efficacious than standard open procedures in terms of patient discomfort, length of hospital stay, cost, and length of time until the patient can return to full activity. Laparoscopic live donor nephrectomies are being performed at our institution in an attempt to make live donation more attractive to the potential donor. The purpose of this study was to retrospectively review the results of laparoscopic live donor nephrectomy (LapNx) and to compare them with those obtained using the standard open approach (OpenNx). Ten consecutive LapNx were performed from February 1995 through April 1996. The control group consisted of the 20 consecutive OpenNx performed at the same institution from January 1991 through January 1995 immediately before the initiation of the LapNx program. Live donors were considered candidates for LapNx if they possessed at least one kidney with normal renal anatomy with single renal vessels and a single ureter. LapNx was safely performed in all cases. No patients required open conversion or blood transfusions. The allograft warm ischemic time for the laparoscopic cases was 4.2+/-1.3 min. All kidneys harvested laparoscopically produced urine on the table immediately upon revascularization. Presently nine of the ten recipients have functioning allografts. At three months posttransplant the calculated recipient creatinine clearances were 67.0+/-11.5 ml/min and 64.8+/-21.4 ml/min for the LapNx and OpenNx groups, respectively (P=NS). The LapNx donors had a significantly decreased estimated blood loss, shorter time until resumption of oral intake, decreased postoperative pain (in terms of decreased analgesic requirements), shorter hospitalization, and a shorter interval until the resumption of full activities (P<0.05 for all). In addition, the LapNx group donors returned to work sooner than the OpenNx group (3.9+/-1.6 wk vs. 6.4+/-3.1 wk, respectively) (P=0.024). Four individuals agreed to donate a kidney only after learning of the availability of the laparoscopic approach. We conclude that laparoscopic live donor nephrectomy is technically feasible. In addition, it may offer significant advantages over the standard open approach in terms of patient comfort and convenience. These advantages may make live donor renal transplantation more attractive to prospective donors. The potential decrease in hospitalization and convalescence may also prove to be financially advantageous. We believe that further careful study of this procedure is warranted.

Vitellogenesis and the vitellogenin gene family

Vitellogenin is synthesized under estrogen control in the liver, extensively modified, transported to the ovary, and there processed to the yolk proteins lipovitellin and phosvitin. In the frog Xenopus laevis there are at least four distinct but related vitellogenin genes. The two genes A1 and A2 have a 95 percent sequence homology in their messenger RNA coding regions, and contain 33 introns that interrupt the coding region (exons) at homologous positions. Sequences and lengths of analogous introns differ, and many introns contain repetitive DNA elements. The introns in these two genes that have apparently arisen by duplication have diverged extensively by events that include deletions, insertions, and probably duplications. Rapid evolutionary change involving rearrangements and the presence of repeated DNA suggests that the bulk of the sequences within introns may not have any specific function.

Cardiac septal and valvular dysmorphogenesis in mice heterozygous for mutations in the homeobox gene Nkx2-5

Heterozygous mutations in the cardiac homeobox gene, NKX2-5, underlie familial cases of atrial septal defect (ASD) with severe atrioventricular conduction block. In this study, mice heterozygous for Nkx2-5-null alleles were assessed for analogous defects. Although ASD occurred only rarely, atrial septal dysmorphogenesis was evident as increased frequencies of patent foramen ovale and septal aneurysm, and decreased length of the septum primum flap valve. These parameters were compounded by genetic background effects, and in the 129/Sv strain, septal dysmorphogenesis bordered on ASD in 17% of Nkx2-5 heterozygotes. In a proportion of neonatal heterozygotes, as well as in adults with ASD, we found that the size of the foramen ovale was significantly enlarged and altered in shape, potentially exposing the normally thin septum primum to excessive hemodynamic forces. Therefore, defective morphogenesis of the septum secundum may be one contributing factor in the generation of patent foramen ovale, septal aneurysm, and certain ASDs. Mild prolongation of P-R interval in females and an increased frequency of stenotic bicuspid aortic valves were also features of the Nkx2-5 heterozygous phenotype. Our data demonstrate that the complex effects of Nkx2-5 haploinsufficiency in mice are weaker but convergent with those in humans. As in the mouse, the phenotype of human NKX2-5 mutations may be modulated by interacting alleles.

The use of the Framingham equation to predict myocardial infarctions in HIV-infected patients: comparison with observed events in the D:A:D Study

BACKGROUND

The D:A:D (Data Collection on Adverse Events of Anti-HIV Drugs) Study, a prospective observational study on a cohort of 23 468 patients with HIV infection, indicated that the incidence of myocardial infarction (MI) increased by 26% per year of exposure to combination antiretroviral treatment (CART). However, it remains unclear whether the observed increase in the rate of MI in this population can be attributed to changes in conventional cardiovascular risk factors.

OBJECTIVE

To compare the number of MIs observed among participants in the D:A:D Study with the number predicted by assuming that conventional cardiovascular risk equations apply to patients with HIV infection.

METHODS

The Framingham equation, a conventional cardiovascular risk algorithm, was applied to individual patient data in the D:A:D Study to predict rates of MI by duration of CART. A series of sensitivity analyses were performed to assess the effect of model and data assumptions. Predictions were extrapolated to provide 10-year risk estimates, and various scenarios were modelled to assess the expected effect of different interventions.

RESULTS

In patients receiving CART, the observed numbers of MIs during D:A:D follow up were similar to or somewhat higher than predicted numbers: 9 observed vs 5.5 events predicted, 14 vs 9.8, 22 vs 14.9, 31 vs 23.2 and 47 vs 37.0 for<1 year, 1-2 years, 2-3 years, 3-4 years and >4 years CART exposure, respectively. In patients who had not received CART, the observed number of MIs was fewer than predicted (3 observed vs 7.6 predicted). Nine per cent of the study population have a predicted 10-year risk of MI above 10%, a level usually associated with initiation of intervention on risk factors.

CONCLUSIONS

A consistent feature of all analyses was that observed and predicted rates of MI increased in a parallel fashion with increased CART duration, suggesting that the observed increase in risk of MI may at least in part be explained by CART-induced changes in conventional risk factors. These findings provide guidance in terms of choosing lifestyle or therapeutic interventions to decrease those risk factors in much the same way as in persons without HIV infection.

Pathogenesis of cervical artery dissections: association with connective tissue abnormalities

BACKGROUND

The etiology of spontaneous cervical artery dissection (CAD) is largely unknown. An underlying connective tissue disorder has often been postulated.

OBJECTIVE

To further assess the association of CAD with ultrastructural abnormalities of the dermal connective tissue.

METHODS

In a multicenter study, skin biopsies of 65 patients with proven nontraumatic CAD and 10 control subjects were evaluated. The ultrastructural morphology of the dermal connective tissue components was assessed by transmission electron microscopy.

RESULTS

Only three patients (5%) had clinical manifestations of skin, joint, or skeletal abnormalities. Ultrastructural aberrations were seen in 36 of 65 patients (55%), consisting of the regular occurrence of composite fibrils within collagen bundles that in some cases resembled the aberrations found in Ehlers-Danlos syndrome type II or III and elastic fiber abnormalities with minicalcifications and fragmentation. A grading scale according to the severity of the findings is introduced. Intraindividual variability over time was excluded by a second biopsy of the skin in eight patients with pronounced aberrations. Recurrent CAD correlated with connective tissue aberrations. In addition, similar connective tissue abnormalities were detected in four first-degree relatives with familial CAD.

CONCLUSION

CAD is associated with ultrastructural connective tissue abnormalities, mostly without other clinical manifestations of a connective tissue disease. A structural defect in the extracellular matrix of the arterial wall leading to a genetic predisposition is suggested. The dermal connective tissue abnormalities detected can serve as a phenotypic marker for further genetic studies in patients with CAD and large families to possibly identify the underlying basic molecular defect(s).

Threshold of detection of Cryptosporidium oocysts in human stool specimens: evidence for low sensitivity of current diagnostic methods

To determine the minimum number of Cryptosporidium oocysts that can be detected in stool specimens by diagnostic procedures, stool samples seeded with known numbers of Cryptosporidium parvum oocysts were processed by the modified Formalin-ethyl acetate (FEA) stool concentration method. FEA concentrates were subsequently examined by both the modified cold Kinyoun acid-fast (AF) staining and fluorescein-tagged monoclonal antibody (immunofluorescence [IF]) techniques. Oocysts were more easily detected in watery diarrheal stool specimens than they were in formed stool specimens. For watery stool specimens, a 100% detection rate was accomplished at a concentration of 10,000 oocysts per g of stool by both the AF staining and IF techniques. In formed stool specimens, 100% of specimens seeded with 50,000 oocysts per gram of stool were detected by the IF technique, whereas 500,000 oocysts per g of stool were needed for a 100% detection rate by AF staining. Counting of all oocysts on IF slides indicated a mean oocyst loss ranging from 51.2 to 99.6%, depending on the stool consistency as determined by the FEA concentration procedure. Our findings suggest that the most commonly used coprodiagnostic techniques may fail to detect cryptosporidiosis in many immunocompromised and immunocompetent individuals.

Vitellogenin in Xenopus laevis is encoded in a small family of genes

Vitellogenin, the yolk protein precursor, is produced in X. laevis liver from a 6.3 kilobase (kb) mRNA. Sequences of this mRNA have been transcribed into cDNA and cloned in E. coli. Some properties of 21 of these cloned DNAs, ranging in size from 1 to 3.7 kb, have been reported by Wahli et al. (1978b). This paper reports restriction endonuclease mapping, cross hybridization, heteroduplex mapping in the electron microscope and heteroduplex melting experiments with these DNAs. We conclude that the cloned DNAs fall into two main groups of sequences which differ from each other in approximately 20% of their nucleotides. Each main group contains two subgroups which differ from each other by about 5% sequence divergence. By hybridizing cloned DNAs with restricted genomic DNA, we showed that sequences corresponding to all four sequence groups are present in a single animal. Furthermore, we have obtained tentative evidence for the presence of large intervening sequences in genomic vitellogenin DNA. Analysis of R loop molecules demonstrated that all four sequences are present in the vitellogenin mRNA population purified from individual animals. While some alternate explanations are not entirely excluded, we suggest that vitellogenin is encoded by a small family of related genes in Xenopus.

HIV viral load response to antiretroviral therapy according to the baseline CD4 cell count and viral load

CONTEXT

It is unclear whether delay in initiation of antiretroviral therapy (ART) may lead to a poorer viral load response for patients with human immunodeficiency virus (HIV).

OBJECTIVE

To characterize the relationship of viral load response to ART with baseline CD4 cell count and baseline viral load.

DESIGN

Inception cohort of 3430 therapy-naive patients with HIV, of whom 3226 patients had at least 1 viral load count after the start of ART.

SETTING

Three cohort studies of patients cared for in HIV clinics in Europe between 1996 and 2000.

PATIENTS

All patients initiating ART consisting of at least 3 drugs initiated in or after 1996 and for whom CD4 cell count and viral load were available in the prior 6 months (at most).

MAIN OUTCOME MEASURES

Viral load decrease to below 500 copies/mL; viral load rebound to above 500 copies/mL (2 consecutive values).

RESULTS

Of 3226 patients during the median follow-up of 119 weeks, 2741 (85%) experienced viral suppression to less than 500 copies/mL by 32 weeks. Relative hazards (RHs) of achieving this were 1.08 (95% confidence interval [CI], 0.98-1.21) and 0.94 (95% CI, 0.84-1.04) for baseline CD4 cell counts between 200 and 349 x 10(6)/L and baseline CD4 cell counts lower than 200 x 10(6)/L, respectively, compared with baseline CD4 cell counts of 350 x 10(6)/L or higher, after adjustment for several factors including baseline viral load. For baseline viral load, the RHs were 0.95 (95% CI, 0.84-1.07) and 0.65 (95% CI, 0.58-0.74), for 10 000 to 99 999 and 100 000 copies/mL or greater, respectively, compared with less than 10 000 copies/mL, but the probability of viral load lower than 500 copies/mL at week 32 was similar in all 3 groups. Subsequent rebound above 500 copies/mL was no more likely with a lower baseline CD4 cell count or higher viral load.

CONCLUSION

In this study, lower CD4 cell counts and higher viral loads at baseline were not associated with poorer virological outcome of ART. Those with baseline viral loads of greater than 100 000 copies/mL had a slower rate of achieving viral suppression.

Cardio- and cerebrovascular events in HIV-infected persons

OBJECTIVE

Recent results from the D:A:D Study indicated that the incidence of myocardial infarction (MI) increased by 26% per year of exposure to combination antiretroviral treatment (CART). The present study was performed to investigate whether this risk was similar when including other cardio- and cerebro-vascular disease events (CCVE).

DESIGN

D:A:D is an international collaboration of 11 cohorts, following 23 468 HIV-infected patients prospectively at 188 clinics in 21 countries situated in Europe, USA and Australia.

METHODS

The end-point was the occurrence of a first CCVE during prospective follow-up, defined as the first of: acute MI, invasive cardiovascular procedures, stroke, or death from other cardiovascular disease. Relative rates (RR) for CCVE from Poisson regression models and 95% confidence intervals (CI) are reported. All models are adjusted for other risk factors for CCVE, including age, gender, ethnicity, family history, body mass index, and smoking status as well as cohort and HIV transmission group.

RESULTS

Over 36 145 person-years of follow-up, 207 patients experienced at least one CCVE (23.7% fatal). The first event was MI in 126 patients, invasive cardiovascular procedure in 39 patients, stroke in 38 patients, and death from other cardiovascular disease in four patients. The incidence of first CCVE was 5.7 per 1000 person-years [95% confidence interval (CI) 5.0-6.5] and increased with longer exposure to CART (RR per year of exposure, 1.26; 95% CI, 1.14-1.38; P < 0.0001).

CONCLUSION

CART increases the risk of CCVD, and this increase is comparable with how CART affects the risk of MI. This finding is consistent with the hypothesis that atherosclerosis is a side-effect of CART.

Enteric viruses and diarrhea in HIV-infected patients. Enteric Opportunistic Infections Working Group

BACKGROUND

Diarrhea occurs frequently among persons with the acquired immunodeficiency syndrome, but the cause often remains unknown. We used a group of diagnostic assays to determine which viruses were etiologic agents of diarrhea in a group of persons infected with the human immunodeficiency virus (HIV).

METHODS

Stool and serum specimens were obtained from HIV-infected patients enrolled in a longitudinal study in Atlanta. Fecal specimens from patients with diarrhea and from control patients without diarrhea were screened by electron microscopy, polyacrylamide-gel electrophoresis, and enzyme immunoassays for rotaviruses, enteric adenoviruses, caliciviruses, picobirnaviruses, and astroviruses. Paired serum samples were tested for antibody responses to Norwalk virus and picobirnavirus.

RESULTS

Viruses were detected in 35 percent of 109 fecal specimens from patients with diarrhea but in only 12 percent of 113 specimens from those without diarrhea (P < 0.001). Specimens from patients with diarrhea were more likely than those from patients without diarrhea to have astrovirus (12 percent vs. 2 percent, P = 0.003); picobirnavirus (9 percent vs. 2 percent, P = 0.017); caliciviruses, including small round structured viruses (6 percent vs. 1 percent, P = 0.062); and adenoviruses (9 percent vs. 3 percent, P = 0.047). They were also more likely to have a mixed viral infection (6 percent vs. 0 percent, P = 0.006). With the use of polyacrylamide-gel electrophoresis to analyze concentrated RNA extracts from stool, picobirnavirus was detected in fecal specimens from 6 of the 65 patients with diarrhea and was associated with prolonged viral shedding and chronic diarrhea. No rotaviruses, enteric adenoviruses, or instances of seroconversion to positivity for Norwalk virus were observed.

CONCLUSIONS

Novel enteric viruses such as astrovirus and picobirnavirus may be more important etiologic agents of diarrhea in HIV-infected patients than previously recognized and may be more common than either bacterial or parasitic enteropathogens.

Molecular characterization of Cryptosporidium isolates obtained from human immunodeficiency virus-infected individuals living in Switzerland, Kenya, and the United States

A total of 22 Cryptosporidium isolates from human immunodeficiency virus-infected patients from Kenya, Switzerland, and the United States were examined at three genetic loci: the 18S ribosomal DNA, HSP-70, and acetyl coenzyme A synthetase genes. Four distinct Cryptosporidium genotypes were identified: (i) the Cryptosporidium parvum "human" genotype, (ii) the C. parvum "cattle" genotype, (iii) Cryptosporidium felis, and (iv) Cryptosporidium meleagridis. This is the first report of C. meleagridis in a human host. These results and those of others indicate that immunocompromised individuals are susceptible to a wide range of Cryptosporidium species and genotypes. Future studies are required to understand the full public health significance of Cryptosporidium genotypes and species in immunocompromised hosts.

Modern concepts of frontal sinus surgery

OBJECTIVES/HYPOTHESIS

To validate the endonasal surgical approach to frontal sinus in inflammatory sinus disease, trauma, and selective tumor surgery, and to define the role of external approaches to the frontal sinus. Endonasal frontal sinusotomy can range from endoscopic removal of obstructing frontal recess cells or uncinate process to the more complex unilateral or bilateral removal of the frontal sinus floor as described in the Draf II-III drainage procedures. In contrast, the osteoplastic frontal sinusotomy remains the "gold standard" for external approaches to frontal sinus disease.

METHODS

A retrospective review of 1286 patients undergoing either endonasal or external frontal sinusotomy by the authors at four university teaching programs from 1977. Prior author reports were updated and previously unreported patient series were combined.

RESULTS

Six hundred thirty-five patients underwent type I frontal sinusotomy, 312 type II sinusotomy, and 156 type III sinusotomy. A successful result was seen in these groups, 85.2% to 99.3%, 79% to 93.3%, and 91.5% to 95%, respectively. External frontal sinusotomy or osteoplastic frontal sinusotomy was successfully performed in 187 of 194 patients. Clinical symptoms, endoscopic findings, computed tomography, and magnetic resonance image scanning, and reoperation rate measured postoperative success.

CONCLUSIONS

A stepwise approach to the surgical treatment of frontal sinusitis, trauma, and selective benign tumors yields successful results as defined by specific criteria which vary from 79% to 97.8%. The details of specific techniques are discussed, essential points emphasized, and author variations noted.

Rates of cardiovascular disease following smoking cessation in patients with HIV infection: results from the D:A:D study(*)

OBJECTIVES

The aim of the study was to estimate the rates of cardiovascular disease (CVD) events after stopping smoking in patients with HIV infection.

METHODS

Patients who reported smoking status and no previous CVD prior to enrolment in the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study were included in this study. Smoking status is collected at each visit as current smoker (yes/no) and ever smoker (yes/no). Time since stopping smoking was calculated for persons who had reported current smoking during follow-up and no current smoking subsequently. Endpoints were: myocardial infarction (MI); coronary heart disease (CHD: MI plus invasive coronary artery procedure or death from other CHD); CVD (CHD plus carotid artery endarterectomy or stroke); and all-cause mortality. Event rates were calculated for never, previous and current smokers, and smokers who stopped during follow-up. Incidence rate ratios (IRRs) were determined using Poisson regression adjusted for age, sex, cohort, calendar year, family history of CVD, diabetes, lipids, blood pressure and antiretroviral treatment.

RESULTS

A total of 27 136 patients had smoking status reported, with totals of 432, 600, 746 and 1902 MI, CHD, CVD and mortality events, respectively. The adjusted IRR of CVD in patients who stopped smoking during follow-up decreased from 2.32 within the first year of stopping to 1.49 after >3 years compared with those who never smoked. Similar trends were observed for the MI and CHD endpoints. Reductions in risk were less pronounced for all-cause mortality.

CONCLUSION

The risk of CVD events in HIV-positive patients decreased with increasing time since stopping smoking. Smoking cessation efforts should be a priority in the management of HIV-positive patients.

Formation of PCDF, PCDD, PCB, and PCN in de novo synthesis from PAH: mechanistic aspects and correlation to fluidized bed incinerators

The difference of polychlorinated dibenzofurans (PCDF) isomer patterns between stoker type incinerators and some fluidized bed incinerators (FBI) is a key to understand the formation mechanisms in both types of incinerators. The total yield and the isomer patterns of PCDF, polychlorinated biphenyls (PCB), polychlorinated naphthalenes (PCN), and polychlorinated benzenes (PCBz) formed via de novo synthesis from polycyclic aromatic hydrocarbons (PAH) indicate that chlorinated aromatics in the FBI are formed as a result of PAH breakdown. The detailed analysis of the isomer patterns of PCDF, PCB and PCN gives a first insight into the transformation mechanism of the PAHs and the sequence of degradation, chlorination and oxygen insertion. The major chlorination takes part at the position of the C-C cleavage during degradation of the PAHs. Further chlorination of the hydrogen position of the former PAH takes part preferably in ortho-position to this chlorination or is directed by incorporated oxygen. A perylene structure in soot is proposed as basis for the observed PCDF pattern in the FBI. Polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated phenols (PxCP) were formed in lower concentrations from the de novo experiments indicating an additional formation pathway for these compounds in the FBI.

Short-term weight gain after antiretroviral therapy initiation and subsequent risk of cardiovascular disease and diabetes: the D:A:D study

OBJECTIVES

The aim of the study was to assess the impact of the gain in body mass index (BMI) observed immediately after antiretroviral therapy (ART) initiation on the subsequent risk of cardiovascular disease (CVD) and diabetes.

METHODS

We analysed data from the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) cohort study. Outcomes were development of (i) CVD (composite of myocardial infarction/stroke/coronary procedure) and (ii) diabetes. The main exposure variable was change in BMI from ART initiation (pre-ART) to 1 year after initiation (continuous variable) in treatment-naïve individuals initiating ART with no history of CVD or diabetes (for respective outcomes). BMI [weight (kg)/(height (m))(2)] was categorized as underweight (< 18.5), normal (18.5-25), overweight (25-30) and obese (> 30). Poisson regression models were fitted stratified for each pre-ART BMI category to allow for category-specific estimates of incidence rate ratio (IRR). Models were adjusted for pre-ART BMI and CD4 count, key known risk factors (time-updated where possible) and calendar year.

RESULTS

A total of 97 CVD events occurred in 43,982 person-years (n = 9321) and 125 diabetes events in 43,278 person-years (n = 9193). In fully adjusted analyses for CVD, the IRR/unit gain in BMI (95% confidence interval) in the first year of ART, by pre-ART BMI category, was: underweight, 0.90 (0.60-1.37); normal, 1.18 (1.05-1.33); overweight, 0.87 (0.70-1.10), and obese, 0.95 (0.71-1.28) (P for interaction = 0.04). For diabetes, the IRR/unit gain in BMI was 1.11 (95% confidence interval 1.03 to 1.21), regardless of pre-ART BMI (P for interaction > 0.05).

CONCLUSIONS

Short-term gain in BMI following ART initiation appeared to increase the longer term risk of CVD, but only in those with pre-ART BMI in the normal range. It was also associated with increased risk of diabetes regardless of pre-ART BMI.

Mesenchymal cells engulf and clear apoptotic footplate cells in macrophageless PU.1 null mouse embryos

Apoptosis is one of the key tools used by an embryo to regulate cell numbers and sculpt body shape. Although massive numbers of cells die during development, they are so rapidly phagocytosed that very few corpses are ever seen in most embryonic tissues. In this paper, we focus on the catastrophic cell death that occurs as the developing footplate is remodelled to transform webbed regions into free interdigital spaces. In the wild-type embryo, these dead cells are rapidly engulfed and cleared by macrophages. We show that in a macrophageless mouse embryo, null for the haemopoetic-lineage-specific transcription factor, PU.1, the task of phagocytosis is taken over by ‘stand-in’ mesenchymal neighbours in a clear example of cell redundancy. However, it takes three times as many of these mesenchymal phagocytes to complete the task and, at each stage of the clearance process - in the recognition of apoptotic debris, its engulfment and finally its digestion - they appear to be less efficient than macrophages. A molecular explanation for this may be that several of the engulfment genes expressed by macrophages, including the ABC1 transporter (believed to be part of the phagocytic machinery conserved from Caenorhabditis elegans to mouse), are not upregulated by these ‘stand-in’ phagocytes.

Diagnostic performance of amplified Mycobacterium tuberculosis direct test with cerebrospinal fluid, other nonrespiratory, and respiratory specimens

The Gen-Probe Amplified Mycobacterium tuberculosis Direct Test (MTD) was adapted to be used for cerebrospinal fluid (CSF) and a large variety of other nonrespiratory specimens. Standardized with artificially spiked dilution series of CSF, the modified MTD procedure consists of (i) increasing the amount of sample 10-fold, (ii) pretreating the specimen with a detergent, and (iii) increasing the amplification time from 2 to 3 h. Performance of MTD in a clinical mycobacteriology laboratory was tested over an extended period of time, involving a total of 322 nonrespiratory as well as 1,117 respiratory specimens from 998 patients. Results from MTD were compared with those from microscopy, culture, analysis of tuberculostearic acid by gas-liquid chromatography-mass spectrometry (CSF only), and the final clinical diagnosis. When MTD results were compared with resolved data, the sensitivity, specificity, and positive and negative predictive values for MTD were 93.1, 97.7, 90.0, and 98.5%, respectively, for nonrespiratory specimens and 86.6, 96.4, 76.8, and 98.1%, respectively, for respiratory specimens. Our data demonstrate that (i) MTD is a robust, highly sensitive and specific technique for the rapid detection of M. tuberculosis complex in all types of clinical specimens, (ii) there was no statistically significant difference (P > 0.005) in sensitivity and specificity for nonrespiratory compared with respiratory specimens, and (iii) repeating all MTDs which yield a result between 30,000 and 200,000 relative light units would help prevent a large number of false positives and, thus, enhance test specificity.

Prevalence of risk factors for cardiovascular disease in HIV-infected patients over time: the Swiss HIV Cohort Study

OBJECTIVE

Metabolic changes caused by antiretroviral therapy (ART) may increase the risk of coronary heart disease (CHD). We evaluated changes in the prevalence of cardiovascular risk factors (CVRFs) and 10-year risk of CHD in a large cohort of HIV-infected individuals.

METHODS

All individuals from the Swiss HIV Cohort Study (SHCS) who completed at least one CVRF questionnaire and for whom laboratory data were available for the period February 2000 to February 2006 were included in the analysis. The presence of a risk factor was determined using cut-offs based on the guidelines of the National Cholesterol Education Program (NCEP ATP III), the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC7), the American Diabetes Association, and the Swiss Society for Cardiology.

RESULTS

Overall, 8,033 individuals completed at least one CVRF questionnaire. The most common CVRFs in the first completed questionnaire were smoking (57.0%), low high-density lipoprotein (HDL) cholesterol (37.2%), high triglycerides (35.7%), and high blood pressure (26.1%). In total, 2.7 and 13.8% of patients were categorized as being at high (>20%) and moderate (10-20%) 10-year risk for CHD, respectively. Over 6 years the percentage of smokers decreased from 61.4 to 47.6% and the percentage of individuals with total cholesterol >6.2 mmol/L decreased from 21.1 to 12.3%. The prevalence of CVRFs and CHD risk was higher in patients currently on ART than in either pretreated or ART-naive patients.

CONCLUSION

During the 6-year observation period, the prevalence of CVRFs remains high in the SHCS. Time trends indicate a decrease in the percentage of smokers and individuals with high cholesterol.