Helen Kovari
University of Zurich
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Featured researches published by Helen Kovari.
The Journal of Pediatrics | 2003
Beatrice Latal-Hajnal; Kurt von Siebenthal; Helen Kovari; Hans Ulrich Bucher
OBJECTIVE To study the significance of growth status at birth and postnatal growth on neurodevelopmental outcome in very low birth weight (VLBW) infants. STUDY DESIGN Growth and neurodevelopment were examined in 219 VLBW (<1250 g) children, 94 small for gestational age (SGA) (<10th percentile) and 125 appropriate for gestational age (AGA) (>10th percentile). Outcome at age 2 was assessed with the Bayley Scales of Infant Development (Mental Developmental Index [MDI], Psychomotor Developmental Index [PDI]) and a standardized neurologic examination. RESULTS SGA status was not associated with poor neurodevelopmental outcome. However, after adjustment for covariables including cerebral palsy (CP), SGA children with weight <10th percentile at age 2 had lower mean PDI than SGA children with catch-up growth to weight >10th percentile (mean [SD], 89.9 [17.4] versus 101.8 [14.5]; P<.001). AGA children with catch-down growth (weight <10th percentile at age 2) were, independent of CP, more likely to have lower mean MDI (94.9 vs 101.7, P=.05) and PDI (81.9 vs 95.1; P<.001) than AGA children remaining >10th percentile at age 2. They also more frequently had severe CP (22.9% vs 1.2%; P=.008). CONCLUSIONS In VLBW children, the course of postnatal growth rather than the appropriateness of weight for gestational age at birth determines later neurodevelopmental outcome.
Clinical Infectious Diseases | 2009
Helen Kovari; Bruno Ledergerber; Ulrich Peter; Markus Flepp; Josef Jost; Patrick Schmid; Alexandra Calmy; Nicolas J. Mueller; Beat Muellhaupt; Rainer Weber
BACKGROUND Noncirrhotic portal hypertension (NCPH) is a newly described life-threatening liver disease of unknown cause in human immunodeficiency virus (HIV)-infected persons. Postulated pathogenesis includes prolonged exposure to antiretroviral therapy, particularly didanosine. METHODS We performed a nested case-control study including 15 patients with NCPH and 75 matched control subjects of the Swiss HIV Cohort Study to investigate risk factors for the development of NCPH. Matching criteria were similar duration of HIV infection, absence of viral hepatitis, and follow-up to at least the date of NCPH diagnosis in the respective case. RESULTS All 15 case patients had endoscopically documented esophageal varices and absence of liver cirrhosis on biopsies; 4 died because of hepatic complications. At NCPH diagnosis, case patients and control subjects were similar concerning sex; race; Centers for Disease Control and Prevention stage; HIV-RNA level; CD4 cell count nadir; and lipids and lipodystrophy. Differences were found in age (conditional logistic regression odds ratio [OR] for 10 years older, 2.9; 95% confidence interval [CI], 1.4-6.1); homosexuality (OR, 4.5; 95% CI, 1.2-17); current CD4 cell count <200 cells/microL (OR, 34.3; 95% CI, 4.3-277); diabetes mellitus (OR, 8.8; 95% CI, 1.6-49); alanine aminotransferase level higher than normal (OR, 13.0; 95% CI, 2.7-63); alkaline phosphatase higher than normal (OR, 18.3; 95% CI, 4.0-85); and platelets lower than normal (OR, 20.5; 95% CI, 2.4-178). Cumulative exposure to antiretroviral therapy (OR per year, 1.3; 95% CI, 1.0-1.6), nucleoside reverse-transcriptase inhibitor (OR, 1.3; 95% CI, 1.1-1.7), didanosine (OR, 3.4; 95% CI, 1.5-8.1), ritonavir (OR, 1.4; 95% CI, 1.0-1.9), and nelfinavir (OR, 1.4; 95% CI, 1.0-1.9) were longer in case patients. Exposure to nonnucleoside reverse-transcriptase inhibitor and other protease inhibitors were not different between groups. In bivariable models, only the association of NCPH with didanosine exposure was robust; other covariables were not independent risk factors. CONCLUSIONS We found a strong association between prolonged exposure to didanosine and the development of NCPH.
Proceedings of the National Academy of Sciences of the United States of America | 2012
Satish K. Pillai; Mohamed Abdel-Mohsen; John C. Guatelli; Mark Skasko; Alexander Monto; Katsuya Fujimoto; Steven A. Yukl; Warner C. Greene; Helen Kovari; Andri Rauch; Jacques Fellay; Manuel Battegay; Bernard Hirschel; Andrea Witteck; Enos Bernasconi; Bruno Ledergerber; Huldrych F. Günthard; Joseph K. Wong
The antiviral potency of the cytokine IFN-α has been long appreciated but remains poorly understood. A number of studies have suggested that induction of the apolipoprotein B mRNA editing enzyme, catalytic polypeptide 3 (APOBEC3) and bone marrow stromal cell antigen 2 (BST-2/tetherin/CD317) retroviral restriction factors underlies the IFN-α–mediated suppression of HIV-1 replication in vitro. We sought to characterize the as-yet-undefined relationship between IFN-α treatment, retroviral restriction factors, and HIV-1 in vivo. APOBEC3G, APOBEC3F, and BST-2 expression levels were measured in HIV/hepatitis C virus (HCV)-coinfected, antiretroviral therapy-naïve individuals before, during, and after pegylated IFN-α/ribavirin (IFN-α/riba) combination therapy. IFN-α/riba therapy decreased HIV-1 viral load by −0.921 (±0.858) log10 copies/mL in HIV/HCV-coinfected patients. APOBEC3G/3F and BST-2 mRNA expression was significantly elevated during IFN-α/riba treatment in patient-derived CD4+ T cells (P < 0.04 and P < 0.008, paired Wilcoxon), and extent of BST-2 induction was correlated with reduction in HIV-1 viral load during treatment (P < 0.05, Pearsons r). APOBEC3 induction during treatment was correlated with degree of viral hypermutation (P < 0.03, Spearmans ρ), and evolution of the HIV-1 accessory protein viral protein U (Vpu) during IFN-α/riba treatment was suggestive of increased BST-2–mediated selection pressure. These data suggest that host restriction factors play a critical role in the antiretroviral capacity of IFN-α in vivo, and warrant investigation into therapeutic strategies that specifically enhance the expression of these intrinsic immune factors in HIV-1–infected individuals.
Emerging Infectious Diseases | 2011
Alain Kenfak-Foguena; Franziska Schöni-Affolter; Philippe Bürgisser; Andrea Witteck; Katharine Darling; Helen Kovari; Laurent Kaiser; John Evison; Luigia Elzi; Vanina Gurtner De La Fuente; Josef Jost; Darius Moradpour; Florence Abravanel; Jacques Izopet; Matthias Cavassini
We screened 735 HIV-infected patients in Switzerland with unexplained alanine aminotransferase elevation for hepatitis E virus (HEV) immunoglobulin G. Although HEV seroprevalence in this population is low (2.6%), HEV RNA can persist in patients with low CD4 cell counts. Findings suggest chronic HEV infection should be considered as a cause of persistent alanine aminotransferase elevation.
Clinical Infectious Diseases | 2010
Helen Kovari; Bruno Ledergerber; Manuel Battegay; Andri Rauch; Bernard Hirschel; Alain Kenfak Foguena; Pietro Vernazza; Enos Bernasconi; Nicolas J. Mueller; Rainer Weber
BACKGROUND Chronic liver disease in human immunodeficiency virus (HIV)-infected patients is mostly caused by hepatitis virus co-infection. Other reasons for chronic alanine aminotransferase (ALT) elevation are more difficult to diagnose. METHODS We studied the incidence of and risk factors for chronic elevation of ALT levels (greater than the upper limit of normal at 2 consecutive semi-annual visits) in participants of the Swiss HIV Cohort Study without hepatitis B virus (HBV) or hepatitis C virus (HCV) infection who were seen during the period 2002-2008. Poisson regression analysis was used. RESULTS A total of 2365 participants were followed up for 9972 person-years (median age, 38 years; male sex, 66%; median CD4+ cell count, 426/microL; receipt of antiretroviral therapy [ART], 56%). A total of 385 participants (16%) developed chronic elevated ALT levels, with an incidence of 3.9 cases per 100 person-years (95% confidence interval [CI], 3.5-4.3 cases per 100 person-years). In multivariable analysis, chronic elevated ALT levels were associated with HIV RNA level >100,000 copies/mL (incidence rate ratio [IRR], 2.23; 95% CI, 1.45-3.43), increased body mass index (BMI, defined as weight in kilograms divided by the square of height in meters) (BMI of 25-29.9 was associated with an IRR of 1.56 [95% CI, 1.24-1.96]; a BMI 30 was associated with an IRR of 1.70 [95% CI, 1.16-2.51]), severe alcohol use (1.83 [1.19-2.80]), exposure to stavudine (IRR per year exposure, 1.12 [95% CI, 1.07-1.17]) and zidovudine (IRR per years of exposure, 1.04 [95% CI, 1.00-1.08]). Associations with cumulative exposure to combination ART, nucleoside reverse-transcriptase inhibitors, and unboosted protease inhibitors did not remain statistically significant after adjustment for exposure to stavudine. Black ethnicity was inversely correlated (IRR, 0.52 [95% CI, 0.33-0.82]). Treatment outcome and mortality did not differ between groups with and groups without elevated ALT levels. CONCLUSIONS Among patients without hepatitis virus co-infection, the incidence of chronic elevated ALT levels was 3.9 cases per 100 person-years, which was associated with high HIV RNA levels, increased BMI, severe alcohol use, and prolonged stavudine and zidovudine exposure. Long-term follow-up is needed to assess whether chronic elevation of ALT levels will result in increased morbidity or mortality.
American Journal of Epidemiology | 2013
Barbara Bertisch; Silvia Franceschi; Mauro Lise; Pietro Vernazza; Olivia Keiser; Franziska Schöni-Affolter; Christine Bouchardy; Silvia Dehler; Fabio Levi; Gernot Jundt; Silvia Ess; Michael Pawlita; Helen Kovari; Gilles Wandeler; Alexandra Calmy; Matthias Cavassini; Marcel Stöckle; Gary M. Clifford
Although persons infected with human immunodeficiency virus (HIV), particularly men who have sex with men, are at excess risk for anal cancer, it has been difficult to disentangle the influences of anal exposure to human papillomavirus (HPV) infection, immunodeficiency, and combined antiretroviral therapy. A case-control study that included 59 anal cancer cases and 295 individually matched controls was nested in the Swiss HIV Cohort Study (1988-2011). In a subset of 41 cases and 114 controls, HPV antibodies were tested. A majority of anal cancer cases (73%) were men who have sex with men. Current smoking was significantly associated with anal cancer (odds ratio (OR) = 2.59, 95% confidence interval (CI): 1.25, 5.34), as were antibodies against L1 (OR = 4.52, 95% CI: 2.00, 10.20) and E6 (OR = ∞, 95% CI: 4.64, ∞) of HPV16, as well as low CD4+ cell counts, whether measured at nadir (OR per 100-cell/μL decrease = 1.53, 95% CI: 1.18, 2.00) or at cancer diagnosis (OR per 100-cell/μL decrease = 1.24, 95% CI: 1.08, 1.42). However, the influence of CD4+ cell counts appeared to be strongest 6-7 years prior to anal cancer diagnosis (OR for <200 vs. ≥500 cells/μL = 14.0, 95% CI: 3.85, 50.9). Smoking cessation and avoidance of even moderate levels of immunosuppression appear to be important in reducing long-term anal cancer risks.
Clinical Infectious Diseases | 2014
Sara M. Drescher; Viktor von Wyl; Wan-Lin Yang; Jürg Böni; Sabine Yerly; Cyril Shah; Vincent Aubert; Thomas Klimkait; Patrick Taffé; Hansjakob Furrer; Manuel Battegay; Juan Ambrosioni; Matthias Cavassini; Enos Bernasconi; Pietro Vernazza; Bruno Ledergerber; Huldrych F. Günthard; Roger D. Kouyos; V. Aubert; J. Barth; M. Battegay; E Bernasconi; J Böni; H C Bucher; C. Burton-Jeangros; A Calmy; Matthias Egger; L Elzi; Jan Fehr; Jacques Fellay
BACKGROUND Human immunodeficiency virus type 1 (HIV-1) transmitted drug resistance (TDR) can compromise antiretroviral therapy (ART) and thus represents an important public health concern. Typically, sources of TDR remain unknown, but they can be characterized with molecular epidemiologic approaches. We used the highly representative Swiss HIV Cohort Study (SHCS) and linked drug resistance database (SHCS-DRDB) to analyze sources of TDR. METHODS ART-naive men who have sex with men with infection date estimates between 1996 and 2009 were chosen for surveillance of TDR in HIV-1 subtype B (N = 1674), as the SHCS-DRDB contains pre-ART genotypic resistance tests for >69% of this surveillance population. A phylogeny was inferred using pol sequences from surveillance patients and all subtype B sequences from the SHCS-DRDB (6934 additional patients). Potential sources of TDR were identified based on phylogenetic clustering, shared resistance mutations, genetic distance, and estimated infection dates. RESULTS One hundred forty of 1674 (8.4%) surveillance patients carried virus with TDR; 86 of 140 (61.4%) were assigned to clusters. Potential sources of TDR were found for 50 of 86 (58.1%) of these patients. ART-naive patients constitute 56 of 66 (84.8%) potential sources and were significantly overrepresented among sources (odds ratio, 6.43 [95% confidence interval, 3.22-12.82]; P < .001). Particularly large transmission clusters were observed for the L90M mutation, and the spread of L90M continued even after the near cessation of antiretroviral use selecting for that mutation. Three clusters showed evidence of reversion of K103N or T215Y/F. CONCLUSIONS Many individuals harboring viral TDR belonged to transmission clusters with other Swiss patients, indicating substantial domestic transmission of TDR in Switzerland. Most TDR in clusters could be linked to sources, indicating good surveillance of TDR in the SHCS-DRDB. Most TDR sources were ART naive. This, and the presence of long TDR transmission chains, suggests that resistance mutations are frequently transmitted among untreated individuals, highlighting the importance of early diagnosis and treatment.
Clinical Infectious Diseases | 2013
Helen Kovari; Caroline Sabin; Bruno Ledergerber; Lene Ryom; Signe Westring Worm; Colette Smith; Andrew N. Phillips; Peter Reiss; Eric Fontas; Kathy Petoumenos; Stéphane De Wit; Philippe Morlat; Jens D. Lundgren; Rainer Weber
BACKGROUND Liver diseases are the leading causes of death in human immunodeficiency virus (HIV)-positive persons since the widespread use of combination antiretroviral treatment (cART). Most of these deaths are due to hepatitis C (HCV) or B (HBV) virus coinfections. Little is known about other causes. Prolonged exposure to some antiretroviral drugs might increase hepatic mortality. METHODS All patients in the Data Collection on Adverse Events of Anti-HIV Drugs study without HCV or HBV coinfection were prospectively followed from date of entry until death or last follow-up. In patients with liver-related death, clinical charts were reviewed using a structured questionnaire. RESULTS We followed 22 910 participants without hepatitis virus coinfection for 114 478 person-years. There were 12 liver-related deaths (incidence, 0.10/1000 person-years); 7 due to severe alcohol use and 5 due to established ART-related toxicity. The rate of ART-related deaths in treatment-experienced persons was 0.04/1000 person-years (95% confidence interval, .01, .10). CONCLUSIONS We found a low incidence of liver-related deaths in HIV-infected persons without HCV or HBV coinfection. Liver-related mortality because of ART-related toxicity was rare.
The Journal of Infectious Diseases | 2013
Gilles Wandeler; Thomas Gsponer; Florian Bihl; Enos Bernasconi; Matthias Cavassini; Helen Kovari; Patrick Schmid; Manuel Battegay; Alexandra Calmy; Matthias Egger; Hansjakob Furrer; Andri Rauch
Hepatitis B virus (HBV) infection is a major cause of morbidity and mortality in human immunodeficiency virus (HIV)-infected patients worldwide. It is unclear whether HIV-related outcomes are affected by HBV coinfection. We compared virological suppression and immunological recovery during antiretroviral therapy (ART) of patients of different HBV serological status in the Swiss HIV Cohort Study. CD4 cell recovery during ART was significantly impaired in hepatitis B surface antigen-positive patients and in those with anti-hepatitis B core antigen alone compared with HBV-uninfected patients, despite similar virological efficacy of ART. CD4 increase in patients with resolved HBV infection was similar to that in HBV-uninfected individuals.
Clinical Infectious Diseases | 2009
Thanh Dang; Katia Jaton-Ogay; Markus Flepp; Helen Kovari; J Evison; Jan Fehr; Patrick Schmid; Emmanuelle Boffi El Amari; Matthias Cavassini; Massimo Odorico; Philip E. Tarr; Gilbert Greub
Human immunodeficiency virus (HIV)-infected men who have sex with men (MSM) were enrolled in an anorectal Chlamydia trachomatis screening study. Anorectal Chlamydia DNA was detected in 16 (10.9%) of 147 men, mainly among asymptomatic patients and patients having >20 sexual partners. These results support routine anorectal Chlamydia screening in HIV-infected MSM who report unprotected anal intercourse.