title: Low Bone Mineral Density in Vertically HIV-infected Children and Adolescents: Risk Factors and the Role of T-cell Activation and Senescence.
abstract: Our aim was to determine the prevalence and risk factors associated with low bone mineral density (BMD) in vertically HIV-infected patients and to investigate whether low BMD is related to immune activation and senescence induced by HIV infection.
  
  
  
  A cross-sectional study was performed in 98 vertically HIV-infected patients. BMD was measured by dual-energy radiograph absorptiometry at lumbar spine. Height adjustment of BMD Z score was performed using height-for-age Z score. T-cell immune activation and senescence were analyzed in a subgroup of 54 patients by flow cytometry.
  
  
  
  Median age was 15.9 years, 71.4% were Caucasian, 99% received antiretroviral therapy and 80.6% had undetectable viral load. Low BMD (BMD Z score ≤ -2) was present in 15.3% of cases, but after height adjustment in 4.1% of cases. Height-adjusted BMD Z score was positively correlated with body mass index Z score, CD4/CD8 ratio and nadir CD4, and inversely with duration of severe immunosuppression and parathyroid hormone values. In the multivariate model including age, gender, ethnicity, encephalopathy, Tanner stage, nadir CD4, duration of viral suppression, CD4 count, CD4/CD8 ratio, body mass index, cumulative duration of antiretroviral therapy, tenofovir and protease inhibitors exposure, nadir CD4 was independently associated to height-adjusted BMD Z score. No association was found between height-adjusted BMD Z score and T-cell activation or senescence.
  
  
  
  The prevalence of low BMD in vertically HIV-infected patients was low after height adjustment. Nadir CD4, but not T-cell activation or senescence, was an independent predictor for low BMD. Larger and prospective studies are needed to achieve better knowledge of the pathogenesis of low BMD in vertical HIV infection.
authors.affiliation: From the *Department of Pediatrics, Health Research Institute San Carlos (IdISSC) and Facultad de Medicina, Hospital Universitario Clínico San Carlos, Madrid, Spain; †Department of Immunology, Laboratorio InmunoBiología Molecular, Hospital General Universitario Gregorio Marañón, Madrid, Spain; ‡Spanish HIV HGM BioBank; Health Research Institute Gregorio Marañón, Madrid, Spain; §Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain; ¶Department of Pediatrics, Infectious and Tropical Diseases, Hospital Universitario La Paz and IdiPaz, Madrid, Spain; ‖Pediatric Infectious Diseases Unit, Department of Pediatrics, Hospital General Universitario Gregorio Marañón, Madrid, Spain; **Pediatric Infectious Diseases and Immunodeficiencies Unit, Hospital Universitario 12 de Octubre, Madrid, Spain; ††Department of Pediatrics, Hospital Universitario de Getafe, Getafe, Spain; and ‡‡Department of Pediatrics, Hospital Universitario Niño Jesús, Madrid, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Jiménez
authors.forename: Talía
authors.initials: T
authors.lastname: Sainz
authors.forename: Laura
authors.initials: L
authors.lastname: Díaz
authors.forename: María José
authors.initials: MJ
authors.lastname: Mellado
authors.forename: María Luisa
authors.initials: ML
authors.lastname: Navarro
authors.forename: Pablo
authors.initials: P
authors.lastname: Rojo
authors.forename: María Isabel
authors.initials: MI
authors.lastname: González-Tomé
authors.forename: Luis
authors.initials: L
authors.lastname: Prieto
authors.forename: Jorge
authors.initials: J
authors.lastname: Martínez
authors.forename: María Isabel
authors.initials: MI
authors.lastname: de José
authors.forename: José Tomás
authors.initials: JT
authors.lastname: Ramos
authors.forename: María Ángeles
authors.initials: MÁ
authors.lastname: Muñoz-Fernandez
mesh_terms: D000293:Adolescent; D000375:Aging / Q000276:immunology; D001827:Body Height; D015519:Bone Density / Q000276:immunology*; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D015658:HIV Infections / Q000453:epidemiology / Q000276:immunology* / Q000503:physiopathology* / Q000635:transmission; D006801:Humans; D018445:Infectious Disease Transmission, Vertical; D008297:Male; D012307:Risk Factors; D018709:Statistics, Nonparametric