THTodd Hulgan

Todd Hulgan

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Todd Hulgan has a total of 178 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Self-reported Cannabis Use and Changes in Body Mass Index, CD4 T-Cell Counts, and HIV-1 RNA Suppression in Treated Persons with HIV

    by James T. Lee, Lauren A. Saag, Aaron M. Kipp, James Logan, Bryan E. Shepherd, John R. Koethe, Megan Turner, Sally Bebawy, Timothy R. Sterling, Todd Hulgan

    Cannabis use is prevalent among HIV-positive persons, but evidence regarding the impact of cannabis in HIV-positive persons is limited. We conducted a retrospective cohort study of HIV-positive adults initiating their first antiretroviral therapy (ART) regimen. A dedicated intake form assessed self-reported cannabis use in the preceding 7 days at each visit. The relationships between time-varying cannabis use and body mass index (BMI), CD4+ T-cell count, and HIV-1 RNA levels were assessed using random effects models adjusted for age, sex, race, and other reported substance use. 4290 patient-visits from 2008 to 2011 were available from 1010 patients. Overall, there were no statistically significant differences in CD4+ T-cell count and BMI across multiple adjusted models using different measures of cannabis use (ever use during the study period, any use, and number of times used in the preceding 7 days). Cannabis use by all three measures was associated with greater odds of having a detectable viral load at a given visit than no reported use (OR 2.02, 1.72, and 1.08, respectively; all adjusted p < 0.05). Self-reported cannabis use was not associated with changes in BMI or CD4+ T-cell count in ART-naïve HIV-positive persons starting treatment. However, reported cannabis use by multiple categories was associated with having a detectable HIV-1 RNA during the study period. Associations between cannabis use, adherence, and HIV-related outcomes merit further study.


  • Factors Associated With Insulin Resistance in Adults With HIV Receiving Contemporary Antiretroviral Therapy: a Brief Update

    by Todd Hulgan

    Purpose of Review This narrative review summarizes recent data on factors associated with insulin resistance (IR) in adults with HIV, including contemporary antiretroviral therapy (ART). Recent Findings IR remains common in persons with HIV, even those receiving contemporary ART. Generalized and abdominal obesity and ectopic fat are correlates of IR, and emerging data have identified associations with biomarkers of inflammation and immune activation. Small studies suggest associations between mitochondria and IR. In ART-naïve individuals, IR increased within 4 weeks of starting ART in persons receiving contemporary boosted protease inhibitors or an integrase inhibitor. Summary The importance of IR in non-diabetic persons with HIV will continue to grow as the population ages and obesity increases. Non-invasive estimates of IR appear to perform well in persons with HIV, but clinically relevant cutoffs are uncertain. Unexpected metabolic effects of newer HIV integrase inhibitors have been reported; thus, careful observation for and studies of IR are still warranted.


  • Open Access

    Cerebrospinal fluid (CSF) biomarkers of iron status are associated with CSF viral load, antiretroviral therapy, and demographic factors in HIV-infected adults

    by Stephanie M. Patton, Quan Wang, Todd Hulgan, James R. Connor, Peilin Jia, Zhongming Zhao, Scott L. Letendre, Ronald J. Ellis, William S. Bush, David C. Samuels, et al.

    HIV-associated neurocognitive disorder (HAND) remains common, despite antiretroviral therapy (ART). HIV dysregulates iron metabolism, but cerebrospinal fluid (CSF) levels of iron and iron-transport proteins in HIV-infected (HIV+) persons are largely unknown. The objectives of this study were to characterize CSF iron-related biomarkers in HIV+ adults and explore their relationships to known predictors of HAND. We quantified total iron, transferrin and heavy-chain (H)-ferritin by immunoassay in CSF sampled by lumbar puncture in 403 HIV+ participants in a multi-center, observational study and evaluated biomarker associations with demographic and HIV-related correlates of HAND [e.g., age, sex, self-reported race/ethnicity, ART, and detectable plasma virus and CSF viral load (VL)] by multivariable regression. In a subset (N = 110) with existing CSF: serum albumin (QAlb) measurements, QAlb and comorbidity severity were also included as covariates to account for variability in the blood–CSF-barrier. Among 403 individuals (median age 43 years, 19% women, 56% non-Whites, median nadir CD4+ T cell count 180 cells/µL, 46% with undetectable plasma virus), men had 25% higher CSF transferrin (median 18.1 vs. 14.5 µg/mL), and 71% higher H-ferritin (median 2.9 vs. 1.7 ng/mL) than women (both p-values ≤0.01). CSF iron was 41% higher in self-reported Hispanics and 27% higher in (non-Hispanic) Whites than in (non-Hispanic) Blacks (median 5.2 and 4.7 µg/dL in Hispanics and Whites, respectively, vs. 3.7 µg/dL in Blacks, both p ≤ 0.01); these findings persisted after adjustment for age, sex, and HIV-specific factors. Median H-ferritin was 25% higher (p < 0.05), and transferrin 14% higher (p = 0.06), in Whites than Blacks. Transferrin and H-ferritin were 33 and 50% higher, respectively, in older (age > 50 years) than in younger persons (age ≤ 35 years; both p < 0.01), but these findings lost statistical significance in subset analyses that adjusted for QAlb and comorbidity. After these additional adjustments, associations were observed for CSF iron and transferrin with race/ethnicity as well as CSF VL, for transferrin with sex and ART, and for H-ferritin with plasma virus detectability and significant comorbidity (all p < 0.05). CSF iron biomarkers are associated with demographic factors, ART, and CSF VL in HIV+ adults. Future studies should investigate a role for CNS iron dysregulation, to which an altered blood-CSF barrier may contribute, in HAND.


  • Open Access

    Cerebrospinal fluid cell-free mitochondrial DNA is associated with HIV replication, iron transport, and mild HIV-associated neurocognitive impairment

    by Sanjay R. Mehta, Josué Pérez-Santiago, Todd Hulgan, Tyler R. C. Day, Jill Barnholtz-Sloan, Haley Gittleman, Scott Letendre, Ronald Ellis, Robert Heaton, Stephanie Patton, et al.

    Mitochondria are abundant organelles critical for energy metabolism and brain function. Mitochondrial DNA (mtDNA), released during cellular injury and as part of the innate immune response to viral pathogens, contains CpG motifs that act as TLR-9 ligands. We investigated relationships between cerebrospinal fluid (CSF) cell-free mtDNA levels and HIV viral load (VL), biomarkers of inflammation and iron transport, and neurocognitive (NC) function in the CNS HIV Antiretroviral Therapy Effects Research (CHARTER) cohort. We quantified cell-free mtDNA in CSF by droplet digital PCR in 332 CHARTER participants who underwent comprehensive neuropsychiatric evaluation. NC performance was assessed using the global deficit score (GDS) as either a continuous or a binary measure (GDS ≥ 0.5, impaired vs. GDS < 0.5, unimpaired). CSF, clinical, and biomarker data from the earliest available time point were analyzed. Cell-free mtDNA associations with CSF inflammation and iron-related biomarkers [CXCL10, IL-6, IL-8, TNF-a, transferrin (TF), ceruloplasmin (CP), and vascular endothelial growth factor (VEGF)], VL, and GDS were evaluated by multivariable regression. CSF cell-free mtDNA levels were significantly lower in participants with undetectable (vs. detectable) VL in either plasma (p < 0.001) or CSF (p < 0.001) and in those on antiretroviral therapy (ART; p < 0.001). Participants on ART with undetectable VL in both CSF and plasma had lower mtDNA levels than those with detectable VL in both compartments (p = 0.001). Higher mtDNA levels were observed in participants in the highest vs. lowest tertile (T3 vs. T1) of CSF CXCL10 (T3 vs. T1, p < 0.001) and TNF-a (T3 vs. T1, p < 0.05) in unadjusted analyses. MtDNA levels also correlated with CSF leukocyte count. After adjusting for CSF leukocyte count and VL, mtDNA levels were also associated with other inflammation- and iron-related biomarkers in CSF, including TF (T3 vs. T1, p < 0.05) and CP (T3 vs. T1, p < 0.05). With additional correction for ART use, mtDNA was also negatively associated with CSF VEGF (p < 0.05) and IL-6 (p = 0.05). We observed no associations of CSF mtDNA levels with age or GDS-defined NC impairment. CSF cell-free mtDNA levels were associated with HIV RNA and ART status, as well as with biomarkers of iron transport and VEGF, a growth factor with known effects on mitochondrial integrity and autophagy. CSF mtDNA may be a biomarker of iron dysregulation and/or neuroinflammation during HIV infection.


  • Open Access

    Mitochondrial DNA Haplogroups and Neurocognitive Impairment During HIV Infection

    by Todd Hulgan, David C. Samuels, William Bush, Ronald J. Ellis, Scott L. Letendre, Robert K. Heaton, Donald R. Franklin, Peter Straub, Deborah G. Murdock, David B. Clifford, et al.

    Background. Neurocognitive impairment (NCI) remains an important complication in persons infected with human immunodeficiency virus (HIV). Ancestry-related mitochondrial DNA (mtDNA) haplogroups have been associated with outcomes of HIV infection and combination antiretroviral therapy (CART), and with neurodegenerative diseases. We hypothesize that mtDNA haplogroups are associated with NCI in HIV-infected adults and performed a genetic association study in the CNS HIV Antiretroviral Therapy Effects Research (CHARTER) cohort. Methods. CHARTER is an observational study of ambulatory HIV-infected adults. Haplogroups were assigned using mtDNA sequence, and principal components were derived from ancestry-informative nuclear DNA variants. Outcomes were cross-sectional global deficit score (GDS) as a continuous measure, GDS impairment (GDS ≥ 0.50), and HIV-associated neurocognitive disorder (HAND) using international criteria. Multivariable models were adjusted for comorbidity status (incidental vs contributing), current CART, plasma HIV RNA, reading ability, and CD4 cell nadir. Results. Haplogroups were available from 1027 persons; median age 43 years, median CD4 nadir 178 cells/mm3, 72% on CART, and 46% with HAND. The 102 (9.9%) persons of genetically determined admixed Hispanic ancestry had more impairment by GDS or HAND than persons of European or African ancestry (P < .001 for all). In multivariate models including persons of admixed Hispanic ancestry, those with haplogroup B had lower GDS (β = −0.34; P = .008) and less GDS impairment (odds ratio = 0.16; 95% confidence interval, .04, .63; P = .009) than other haplogroups. There were no significant haplogroup associations among persons of European or African ancestry. Conclusions. In these mostly CART-treated persons, mtDNA haplogroup B was associated with less NCI among persons of genetically determined Hispanic ancestry. mtDNA variation may represent an ancestry-specific factor influencing NCI in HIV-infected persons.


  • Open Access

    Current drug use and lack of HIV virologic suppression: point-of-care urine drug screen versus self-report

    by Han-Zhu Qian, Valerie J Mitchell, Sally Bebawy, Holly Cassell, Gina Perez, Catherine C McGowan, Timothy R Sterling, Sten H Vermund, Richard D’Aquila, Todd Hulgan


  • Epidermal nerve fiber density, oxidative stress, and mitochondrial haplogroups in HIV-infected Thais initiating therapy

    by Todd Hulgan, Rebecca T. Levinson, Mariana Gerschenson, Nittaya Phanuphak, Jintanat Ananworanich, Nipat Teeratakulpisarm, Tanate Jadwattanakul, Daniel E. LiButti, Heidi Fink, Justin C. McArthur, et al.

    Objective: We explored associations between mitochondrial DNA (mtDNA) haplogroups, epidermal nerve fiber density (ENFD), and HIV-associated sensory neuropathy (HIV-SN) in a randomized trial of Thai patients initiating antiretroviral therapy (ART). Design: The South East Asia Research Collaboration with Hawaii 003 study evaluated toxicity of nucleoside reverse transcriptase inhibitors (stavudine vs. zidovudine vs. tenofovir). We present secondary analyses of mtDNA haplogroups and ENFD changes. Methods: ENFD, peripheral blood mononuclear cell mitochondrial complex I and IV, and 8-oxo-deoxyguanine (8-oxo-dG) were quantified. Peripheral blood mononuclear cell mtDNA sequences were obtained for haplogroup determination. Multivariate regression of ENFD change was performed. Results: Paired ENFD was available from 118 patients. Median age, CD4+ cell count, and height at entry were 34 years, 172 cells/μl, and 162 cm, respectively. Major haplogroups included M (42%), F (21%), and B (16%). Baseline ENFD, CD4+ cell count, randomized ART, and biomarkers did not differ by haplogroup. Haplogroup B patients were older (P = 0.02) at baseline, and had an increase in median ENFD (+1.5 vs. −2.9 fibers/mm; P = 0.03) and 8-oxo-dG break frequency (+0.05 vs. 0.00; P = 0.05) compared to other haplogroups. In a multivariate model, haplogroup B was associated with increased ENFD (β = 3.5, P = 0.009) at week 24, whereas older age (P = 0.02), higher baseline CD4+ cell count, (P = 0.03), higher complex I level (P = 0.03), and higher ENFD (P < 0.001) at baseline were all associated with decreased ENFD. Three of the six HIV-SN cases were haplogroup B (P = 0.05). Conclusions: Thai persons belonging to mtDNA haplogroup B had increased ENFD and 8-oxo-dG on ART, and were more likely to develop HIV-SN. These results suggest that mtDNA variation influences early oxidative damage and ENFD changes.


    • 1 October 2013
      • Vol. 15  (4) , 213-220

    The Other Genome: A Systematic Review of Studies of Mitochondrial DNA Haplogroups and Outcomes of HIV Infection and Antiretroviral Therapy

    by Anna B. Hart, David C. Samuels, Todd Hulgan

    Mitochondrial toxicity is implicated in some treatment-limiting antiretroviral therapy complications, and reports of mitochondrial dysfunction in untreated HIV infection suggest antiretroviral therapy independent effects of NW Several studies have explored associations between mtDNA haplogroups (patterns of mtDNA polymorphisms) and outcomes of HIV infection and/or antiretroviral therapy, but findings have been inconsistent. We systematically reviewed published studies examining mtDNA haplogroups in HIV-infected persons to summarize reported outcome associations, and to highlight potential future research directions. We identified 21 articles published from 2005-2013. Multiple different phenotypes were studied; most were antiretroviral therapy associated metabolic outcomes (e.g. lipodystrophy, insulin resistance, and dyslipidemia). Haplogroup H was associated with the most outcomes, including AIDS progression, CD4 T-cell recovery, cirrhosis (in hepatitis C coinfection), and metabolic outcomes. This review is the first to focus on the emerging area of mtDNA haplogroups in HIV and summarizes the published literature on associations between mtDNA haplogroups and clinical outcomes in populations of European and African descent. Several reported associations require replication and ideally biological verification before definitive conclusions can be drawn, but research in this area has the potential to explain outcome disparities and impact clinical management of patients.


  • Mitochondrial DNA Variation and Changes in Adiponectin and Endothelial Function in HIV-Infected Adults After Antiretroviral Therapy Initiation

    by Todd Hulgan, James H. Stein, Bruno R. Cotter, Deborah G. Murdock, Marylyn D. Ritchie, Michael P. Dube, Mariana Gerschenson, David W. Haas, Francesca J. Torriani

    Studies in persons of European descent have suggested that mitochondrial DNA (mtDNA) haplogroups influence antiretroviral therapy (ART) toxicity. We explored associations between mtDNA variants and changes in endothelial function and biomarkers among non-Hispanic white, ART-naive subjects starting ART. A5152s was a substudy of A5142, a randomized trial of initial class-sparing ART regimens that included efavirenz or lopinavir/ritonavir with nucleoside reverse transcriptase inhibitors (NRTIs), or both without NRTIs. Brachial artery flow-mediated dilation (FMD) and cardiovascular biomarker assessments were performed at baseline and at weeks 4 and 24. Ten haplogroup-defining mtDNA polymorphisms were determined. FMD and biomarker changes from baseline to week 24 by mtDNA variant were assessed using Wilcoxon rank-sum tests. Thirty-nine non-Hispanic white participants had DNA and 24-week data. The nonsynonymous m.10398A>G mtDNA polymorphism ( N =8) was associated with higher median baseline adiponectin (5.0 vs. 4.2 μg/ml; p =0.003), greater absolute (−1.9 vs. −0.2 μg/ml) and relative (−33% vs. −3%) adiponectin decreases ( p p =0.04). Individual mtDNA haplogroups, including haplogroups H ( N =13) and U ( N =6), were not associated with adiponectin or FMD changes. In this small pilot study, adiponectin and brachial artery FMD on ART differed in non-Hispanic whites with a nonsynonymous mtDNA variant associated with several human diseases. These preliminary findings support the hypothesis that mtDNA variation influences metabolic ART effects. Validation studies in larger populations and in different racial/ethnic groups that include m.10398G carriers are needed.


  • Mitochondrial DNA variation and HIV-associated sensory neuropathy in CHARTER

    by for the CHARTER Group, Emily R. Holzinger, Todd Hulgan, Ronald J. Ellis, David C. Samuels, Marylyn D. Ritchie, David W. Haas, Asha R. Kallianpur, Cinnamon S. Bloss, David B. Clifford, et al.

    HIV-associated sensory neuropathy remains an important complication of combination antiretroviral therapy and HIV infection. Mitochondrial DNA haplogroups and single nucleotide polymorphisms (SNPs) have previously been associated with symptomatic neuropathy in clinical trial participants. We examined associations between mitochondrial DNA variation and HIV-associated sensory neuropathy in CNS HIV Antiretroviral Therapy Effects Research (CHARTER). CHARTER is a USA-based longitudinal observational study of HIV-infected adults who underwent a structured interview and standardized examination. HIV-associated sensory neuropathy was determined by trained examiners as ≥1 sign (diminished vibratory and sharp–dull discrimination or ankle reflexes) bilaterally. Mitochondrial DNA sequencing was performed and haplogroups were assigned by published algorithms. Multivariable logistic regression of associations between mitochondrial DNA SNPs, haplogroups, and HIV-associated sensory neuropathy were performed. In analyses of associations of each mitochondrial DNA SNP with HIV-associated sensory neuropathy, the two most significant SNPs were at positions A12810G [odds ratio (95 % confidence interval) = 0.27 (0.11–0.65); p = 0.004] and T489C [odds ratio (95 % confidence interval) = 0.41 (0.21–0.80); p = 0.009]. These synonymous changes are known to define African haplogroup L1c and European haplogroup J, respectively. Both haplogroups were associated with decreased prevalence of HIV-associated sensory neuropathy compared with all other haplogroups [odds ratio (95 % confidence interval) = 0.29 (0.12–0.71); p = 0.007 and odds ratio (95 % confidence interval) = 0.42 (0.18–1.0); p = 0.05, respectively]. In conclusion, in this cohort of mostly combination antiretroviral therapy-treated subjects, two common mitochondrial DNA SNPs and their corresponding haplogroups were associated with a markedly decreased prevalence of HIV-associated sensory neuropathy.