Abstract
Medicare Expands Coverage to Include HIV Screening Tests
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Under the recently passed Medicare Improvements for Patients and Providers Act of 2008 (MIPPA), CMS now has the flexibility of adding to Medicare's list of covered preventive services, if certain requirements are met. Prior to this law, Medicare could only cover additional preventive screening tests when Congress authorized it to do so.
Under MIPPA, CMS can consider whether Medicare should cover preventive services that Congress has not already deemed as covered or non-covered by law. Among other requirements, the new services must have been “strongly recommended” or “recommended” by the U.S. Preventive Services Task Force. For instance, the Task Force graded HIV screening as “strongly recommended” for certain groups. More information about the Task Force is available online (
CMS uses the national coverage determination (NCD) process to make decisions on these types of preventive services. This process provides transparency about the evidence that CMS considers when making its decisions and allows opportunity for the public to comment on CMS' proposals.
Memory Loss Linked to Alzheimer's Protein
More than half of HIV patients experience memory problems and other cognitive impairments as they age. Researchers from Washington University School of Medicine in St. Louis have found that HIV-related cognitive deficits share a common link with Alzheimer's-related dementia. There are low levels of the protein amyloid beta in the spinal fluid.
By analyzing biomarkers in the fluid surrounding the brain and spinal cord, the researchers could distinguish patients with HIV-related cognitive impairments from patients with mild Alzheimer's disease. As patients with HIV age, some will develop cognitive deficits related to HIV and others to Alzheimer's. New treatments in the pipeline to improve memory and thinking may not work for both conditions.
The researchers looked at the spinal fluid of 49 HIV patients with cognitive impairments, 21 HIV patients with normal cognitive function, 68 patients with mild Alzheimer's, and 50 normal, healthy controls. The Alzheimer's patients were older (average age 74) than the controls (average age 50), impaired HIV patients (average age 48) and cognitively normal HIV patients (average age 43). Almost all HIV patients in the study were taking anti-retroviral therapy.
They tested the spinal fluid for the presence of amyloid beta. This is the protein that folds and accumulates in the brains of Alzheimer's patients. It is thought to play a key role in driving the brain damage that characterizes the disease. They also looked at other biomarkers associated with Alzheimer's, including tau, a protein found in tangled nerve fibers in Alzheimer's patients. When amyloid beta accumulates in the brains of Alzheimer's patients, levels decrease in the spinal fluid. The researchers expected to find low levels of the protein in samples of the Alzheimer's patients they studied.
However, they were surprised to find the same low levels in the spinal fluid of HIV patients with cognitive dysfunction. Both groups of patients had significantly lower amyloid beta levels than HIV patients without cognitive impairments and the normal controls. The lower levels are an indicator that amyloid beta in the brain alters the normal turnover of the protein in the body. Patients with mild Alzheimer's had significantly higher levels of tau than either group of HIV patients or normal controls. This finding strongly suggests that Alzheimer's and HIV cognitive dysfunction are not one and the same. HIV-related cognitive impairment may be due to low levels of the virus that hide out in the brain, beyond the reach of drugs that can't easily cross the blood-brain barrier. Another cause may be low-grade inflammation in the brain that is driven by the virus.
The study was published in the December 8th, 2009 issue of Neurology 2009;73(23):1982–1987.
New Drug Shows Promise as HCV Therapy
A new drug for HCV infection that targets liver cells has shown a substantial drop in viremia in chimpanzees and continued to be effective several months after treatment. The drug, SPC3649, was developed by the biopharmaceutical firm Santaris Pharma A/S in Denmark using their proprietary nucleic acid chemistry called “locked nucleic acid” or LNA. SPC3649 is a nucleic acid, or DNA-based drug, that captures a small RNA molecule in the liver (microRNA122) required for HCV replication. Researchers at the Southwest Foundation for Biomedical Research (SFBR) in San Antonio are investigating the compound.
SPC3649 also showed a high barrier to resistance, a major problem with therapies that directly target the virus. Moreover, this proof of concept study suggests that the technology might also prove useful in treating many other diseases such as HIV, cancer, and inflammatory diseases.
The new therapy could potentially replace interferon in the future, since it provides a high barrier to resistance. According to the researchers, the compound could be used as monotherapy to treat disease progression. In addition, it may be able to convert interferon non-responders to responders. Non-responders could be treated with the combination of SPC3649 with interferon. In addition, the compound might be used after transplant in order to suppress HCV in the new liver. SPC3649 has no toxic or adverse reactions.
For this study, four HCV chronically infected chimpanzees were treated with SPC3649. The two chimps that received the higher dose had a drop in viral levels in the blood and liver of 2.5 orders of magnitude or approximately 350-fold. There was a lack of antiviral resistant mutants. The therapy continued to work for several months after dosing stopped.
According to the researchers, the study was a critical proof of concept that the LNA technology could work for HCV. It proved that miR-122 was truly required for HCV replication in an animal infected with HCV. Previously, the role of miR-122 in HCV replication had only been shown in tissue culture. A second finding is that LNA therapy could work against an important disease model, suggesting that the new technology can be applied to other diseases.
More details about the study can be found in the January 8th, 2010 issue of Science 2010;327:198–201.
Barriers Prevent HPV Vaccination in Low-Income Populations
Results of two separate studies show lower rates of HPV vaccination in low-income populations. In addition, there are striking disparities in knowledge and awareness of HPV vaccines in different low-income minority groups. According to researchers at the University of California, Los Angeles (UCLA), several barriers have been identified that can be addressed to help increase HPV vaccine uptake rates.
In the first study, researchers surveyed 390 mothers of girls aged 9 to 18 years who were registered with the Los Angeles County Office of Women's Health. Fifty-four percent of the participants were Latina, 20% were Chinese, 13% were Korean, 8% were black, and 6% were of other ethnic origin.
Vaccination rates were comparable to that of state and national estimates. However, there were significant gaps in the level of knowledge and awareness of HPV vaccine between ethnic groups. While 64% of respondents reported having heard of the HPV vaccine, among Koreans the rate was only 42%. Only 28% of participants said they had enough information to make an informed decision about HPV vaccination. Koreans (14%) and Chinese (17%) had the lowest rates compared with Latinas (31%) and blacks (56%).
Twenty-eight percent of the participating mothers reported knowing where to take their daughters to get the vaccine. This knowledge differed by ethnicity, with the lowest rates among Koreans (16%) and Chinese (19%) compared with blacks (29%) and Latinas (35%). According to mothers of unvaccinated girls, barriers of HPV vaccination included concern over side effects, medical cost, and insufficient information to make an informed decision.
Results of another study showed that a lack of health care provider recommendation and poor uptake of the three-dose HPV vaccine series results in below average vaccination in low-income populations where the vaccine is readily available. Researchers at the University of Texas Southwestern Medical Center, Dallas colleagues conducted the study at two neighborhood-based safety net clinics. They examined the medical records of 353 female patients aged 11 to 18 years old. Results showed that 39.7% of eligible patients received a recommendation by their health care provider to receive the HPV vaccine. Of those patients, 24.3% refused the vaccine. Overall, 30% of patients received the first dose of the vaccine in the series. Only 6.5% completed all three doses required in the HPV vaccine series.
Based on the results of this study, the Parkland Health & Hospital System has adopted a new electronic medical records system that alerts their health care professionals if a patient is eligible for the HPV vaccine. Also, an automatic telephone system reminds the patient to keep clinic appointments and to receive their second and third HPV vaccine doses.
The findings from both studies were presented at the American Association for Cancer Research Frontiers in Cancer Prevention Research Conference, held in Houston, Texas, December 6–9, 2009.
Unacculturated Hispanics in U.S. at Higher Risk for HIV
Researchers from the University of California Los Angeles (UCLA) have found that Hispanics with low levels of acculturation — meaning adaptation to American culture — had fewer HIV tests and no hepatitis C tests. They were also more likely to test positive for HIV and have low levels of access to health care.
In this study, the UCLA team surveyed 600 Hispanics recruited from Los Angeles County sexually transmitted disease clinics, community-based organizations, and needle-exchange programs.
According to the researchers, interventions must be developed that address the cultural and behavioral differences among Hispanics, who are disproportionately affected by HIV/AIDS. U.S Centers for Disease Control statistics from 2006 show that while Hispanics constitute approximately 14% of the nation's population, they account for 22% of new HIV and AIDS cases. The rate of HIV/AIDS among Hispanics continues to rise.
More information about the study can be found in the November 2009 issue of the Journal of Health Care for the Poor and Underserved 2009;20(4):996–1011.
Obesity May Adversely Affect HIV Treatment
The immune systems of HIV patients who are obese don't respond to antiretroviral therapy as well as do those of people of normal weight, according to researchers from the Uniformed Services University of the Health Sciences (USU). Specifically, patients who are obese have lower increases in CD4+ cells after initiating antiretroviral therapy compared to normal weight patients.
The study was based on data collected by the USU's Infectious Disease Clinical Research Program (IDCRP) from participants in the U.S. Military Natural History Study, which includes 1,119 people with documented dates of HIV seroconversion between 1986 and 2008.
According to the researchers, lower CD4+ cell counts may be another negative consequence of being obese. They recommend that patients with HIV infection pay attention to maintaining a healthy weight. One reason for the findings may be that current antiretroviral dosing may not be adequate enough for obese patients. Excess pounds may also have an adverse effect on the efficacy of these medications.
The study was presented at the 47th Annual Meeting of the Infectious Diseases Society of America, Philadelphia, PA, October 29–November 1.