Publications

HIV RNA levels are influenced by genetic characteristics of both the host and the virus. Here we applied machine learning techniques to determine if plasma-derived HIV-1 amino acid sequences can be used to predict spontaneous virologic control. We studied the relationship between HIV-1 env genotype and viral load in 20 chronically infected patients undergoing treatment interruptions (SSITT, Swiss-Spanish Intermittent Treatment Trial) and in 104 primary HIV infected (PHI) patients before antiretroviral therapy (cART) and where applicable also after treatment stop. Extensive longitudinal sampling during the interruptions was performed in nine SSITT patients. Sequences obtained from these nine patients during the first virus rebound were used as a training data set and revealed a strong genetic signature (accuracy 98.6% in cross-validation) associated with control of viremia at levels below 5000copies/mL of viral RNA maintained for at least 2 months after the final cART stop. The simple sequence pattern at gp120 positions 268E/358T was confirmed to be predictive of control in the clonal sequences originating from these patients during all subsequent rebounds. Sequences from the remaining 11 SSITT patients with less frequent sampling and from the PHI patients were used for external validation. High sensitivities (71-100%) and negative predictive values (80-100%) but low positive predictive values (12-40%) were achieved in the patient-wise analysis which was based on presence of the genetic pattern in all clones. These results suggest that presence of virus lacking the amino acid pattern 268E/358T is associated with VL >5000 at baseline of PHI and with low probability of spontaneous virologic control after treatment stop. Conversely, however, presence of 268E/358T does not predict control of viremia. These residues in HIV gp120 might affect in vivo HIV-1 fitness either at the level of Env function or influence susceptibility to adaptive or innate immune response.

Expression of HLA-B57 is associated with restricted replication of human immunodeficiency virus (HIV), but the mechanism for its protective effect remains unknown. If this advantage depends upon CD8 T-cell recognition of B57-restricted epitopes, mother-to-child transmission of escape mutations within these epitopes could nullify its protective effect. However, if the B57 advantage is largely mediated by selection for fitness-attenuating viral mutations within B57-restricted epitopes, such as T242N in TW10-Gag, then the transmission of such mutations could facilitate viral control in the haploidentical infant. We assessed the consequences of B57-associated mutations on replication capacity, viral control, and clinical outcome after vertical transmission in 13 mother-child pairs. We found that expression of HLA-B57 was associated with exceptional control of HIV during infancy, even when mutations within TW10 and most other B57-restricted epitopes were transmitted, subverting the natural immunodominance of HLA-B57. In contrast, most B57-negative infants born to B57-positive mothers progressed rapidly to AIDS. The presence of T242N led to a reproducible reduction in viral fitness, as demonstrated by in vitro assays using NL4-3 constructs encoding p24 sequences from individual mothers and infants. Associated compensatory mutations within p24-Gag were observed to reverse this impairment and to influence the propensity of T242N to revert after transmission to B57-negative hosts. Moreover, primary failure to control viremia was observed in one infant to whom multiple compensatory mutations were transmitted along with T242N. These parallel in vivo and in vitro data suggest that HLA-B57 confers its advantage primarily by driving and maintaining a fitness-attenuating mutation in p24-Gag.

We report the case of an adult patient with pineoblastoma (PBL) who had a complete radiographic response following treatment with vorinostat and retinoic acid. This regimen was used to treat bulky residual tumor that persisted despite radiation therapy (RT) and two cycles of cytotoxic chemotherapy. Vorinostat and retinoic acid were chosen as an alternative to cytotoxic chemotherapy, which our patient was unable to tolerate, based on preclinical data suggesting efficacy of this combination. MRI demonstrated a complete response to this regimen, which continues to remain stable without evidence of recurrence.

OBJECTIVES

This study sought to define the relationship between oxidative biomarkers, cardiovascular disease (CVD) risk factors, and inflammatory and thrombosis biomarkers.

BACKGROUND

Elevated levels of oxidized phospholipids (OxPL) on apolipoprotein B particles (apoB) represent a novel biomarker of CVD. Previous studies suggest that an increase in OxPL/apoB reflects a positive response to statins and a low-fat diet.

METHODS

This study measured OxPL/apoB, lipoprotein (a) [Lp(a)], and oxidized low-density lipoprotein (OxLDL) biomarkers, consisting of immunoglobulin (Ig)G and IgM autoantibodies to malondialdehyde (MDA)-low-density lipoprotein (LDL) and IgG and IgM apoB-100 immune complexes (IC/apoB), at baseline and after 16 weeks of treatment with atorvastatin 80 mg/day or placebo in 2,342 patients with acute coronary syndromes (ACS) enrolled in the MIRACL (Myocardial Ischemia Reduction With Aggressive Cholesterol Lowering) trial.

RESULTS

At baseline, potentially atheroprotective IgM autoantibodies and IgM IC/apoB were lower in male patients, diabetic patients, and patients >65 years of age. Patients with an LDL level greater than the median (122 mg/dl) had higher levels of OxPL/apoB, Lp(a), and OxLDL biomarkers compared with those who had an LDL level less than the median. Atorvastatin resulted in significantly larger changes in all biomarkers in female patients, patients age <65 years, patients with LDL cholesterol <122 mg/dl, nonsmokers, and nondiabetic patients (p < 0.0001 for all). In particular, a significant increase in OxPL/apoB in response to atorvastatin was noted in all 20 subgroups evaluated. Weak or no significant correlations were noted between all OxLDL biomarkers and C-reactive protein, serum amyloid A, tissue plasminogen activator, interleukin-6, intercellular adhesion molecule, vascular cell adhesion molecule, P-selectin, and E-selectin at randomization and 16 weeks.

CONCLUSIONS

In patients with ACS, baseline levels of oxidative biomarkers varied according to specific CVD risk factors and were largely independent of inflammatory biomarkers. Atorvastatin uniformly increased OxPL/apoB levels in all subgroups studied. Future studies are warranted to assess whether the increase in OxPL/apoB levels reflects the benefit of effective therapeutic interventions and prediction of new CVD events.

BACKGROUND AND AIM

The endoscopic landmark of esophagogastric junction (EGJ) for diagnosis of Barrett's esophagus (BE) differs between Japan and Western countries. Japanese endoscopists use the distal end of the lower esophageal palisade vessels to localize EGJ. In the West, endoscopists use the proximal gastric folds because of concerns that palisade vessels may be difficult to recognize. We evaluated whether there were differences between American and Japanese endoscopists in the recognition of palisade vessels.

METHOD

A total of 82 patients were enrolled in this study. Patients were referred for diagnostic esophagogastroduodenoendoscopy (EGD) at the Veterans Affairs Palo Alto Health Care System, from May to July 2008. American and Japanese endoscopists evaluated the EGJ of patients undergoing diagnostic EGD. We analyzed the differences in the recognition of the distal end of palisade vessels. We calculated the kappa statistic to measure interobserver variability.

RESULTS

Based on localization using the distal end of the palisade vessels, American and Japanese endoscopists identified the EGJ in 87.8% (72/82) and 89.0% (73/82) of cases, respectively. The kappa statistic for visualization of EGJ was 0.88 [95% confidence interval (CI): 0.73-1.00].

CONCLUSION

American and Japanese endoscopists similarly recognized the distal end of palisade vessels as EGJ.