Monday, 5 November 2018

HPV blood test shows promise for tracking head and neck cancer after treatment


A new blood test developed by University of North Carolina Lineberger Comprehensive Cancer Center researchers shows promise for tracking HPV-linked head and neck cancer patients to ensure they remain cancer-free after treatment.


Researchers will present preliminary findings at the 60th Annual Meeting of the American Society for Radiation Oncology in San Antonio on Tuesday, Oct. 23. Their study evaluated a blood test for HPV-linked oropharyngeal squamous cell carcinoma, which is a cancer of the back of the throat. The findings demonstrated the test could be an effective and less costly alternative for monitoring for cancer recurrence after radiation treatment.
"The goal of this study was to evaluate whether this test can be used to track patients who are completely asymptomatic, and thought to have no active cancer," said UNC Lineberger's Gaorav P. Gupta, MD, PhD, assistant professor in the UNC School of Medicine Department of Radiation Oncology. "We already knew that our test was very sensitive and specific, but we did not know the degree to which it would be useful in early detection of disease recurrence in patients who are otherwise thought to be disease-free."
HPV, or the human papillomavirus, is the most common cause of sexually transmitted infection in the United States, according to the U.S. Centers for Disease Control and Prevention. Infection with certain strains of HPV can cause cervical cancer in women, genital cancers in both men and women, and cancer of the oropharynx, which is the back of the throat, including the base of the tongue and tonsils. The CDC estimates that approximately 70 percent of oropharyngeal cancer cases diagnosed in the United States are probably caused by HPV, which accounts for nearly 13,000 cases per year.
Gupta and his colleagues developed a blood test that can detect fragments of HPV's genetic material that have been released into the blood by dying cancer cells.
"We realized it is important to distinguish HPV DNA that's being released by dying tumor cells from the natural HPV DNA that is present during a viral infection," Gupta said. "Our method accomplishes this feat, thus making it a more sensitive and specific test for cancer."
For their study, the researchers followed 89 patients with HPV-associated oropharyngeal squamous cell carcinoma who received chemotherapy and radiation treatment. They administered the blood test before and during treatment, and then during follow-up visits. The patients received scans three months after treatment, and then came back for clinical exams every two to four months during the first two years, and then every six months in years three through five. Patients received X-rays or CT scans every six months, and again if they had positive HPV results.
"We are detecting subclinical disease with this blood test, and the imaging patients received confirmed those findings," said UNC Lineberger's Bhishamjit S. Chera, MD, associate professor in the UNC School of Medicine Department of Radiation Oncology and the study's co-corresponding author. Chera presented the findings from the study at the ASTRO meeting.
Of the 70 patients whose blood tests were negative three months after treatment, none developed recurrence. Nineteen patients had positive blood tests, and eight of those patients developed recurrence. Physicians are continuing to monitor the remaining eleven who had positive blood tests but no evidence of recurrence.
"The most striking finding of our study is that of the patients who did not have any signal using our blood test, none of them developed disease recurrence," Chera said. "That raises the question: Do we need to be scanning these patients? Scans come with a lot of cost, and because of the cost, we're not able to do it as frequently. Patients end up having a lot of anxiety from one scan to the next, wondering if their cancer has come back. This blood test could spare patients the need for additional imaging and potentially alleviate some anxiety."
The researchers say the next steps will involve investigating whether the test can be used prospectively to monitor patients and to make decisions that could avoid unnecessary imaging, thereby reducing costs. They also see additional applications for the blood test, including monitoring for other HPV-linked cancers, including cervical cancer.
"We are confident this blood test will be translatable to other cancers driven by HPV, and as a monitoring tool for cancer diagnosis," Chera said. "We strongly believe that this test may also have a role in screening, not just for oropharyngeal cancer, but also cervical or anal cancers, possibly in a general population setting, or at least in patients who may be at higher risk of developing these conditions."
In addition to Chera and Gupta, other authors include Sunil Kumar, PhD; Colette Shen, MD, PhD; Robert Amdur, MD; Roi Dagan, MD; Jared Weiss, MD; Juneko Grilley-Olson, MD; Adam Zanation, MD; Trevor Hackman, MD; Jeff Blumberg, MD; Samip Patel, MD; Brian Thorp, MD; Mark Weissler, MD; Nathan Sheets, MD; and William Mendenhall, MD.
The study was supported by the University Cancer Research Fund, Burroughs Wellcome Fund, the University of North Carolina School of Medicine Department of Radiation Oncology, UNC Lineberger and the University of Florida School of Medicine Department of Radiation Oncology.
Intellectual property related to the test and held by the University of North Carolina at Chapel Hill has been licensed to Naveris, a company in which Chera and Gupta hold equity stakes.

Wednesday, 31 October 2018

No 'reservoir': Detectable HIV-1 in treated human liver cells found to be inert

Novel study suggests HIV-1 still detectable in human liver macrophages unlikely to stay infectious after long-term antiretroviral therapy. In a proof-of-principle study, researchers at Johns Hopkins report that a certain liver immune cell called a macrophage contains only defective or inert HIV-1 copies and aren't likely to restart infection on their own in HIV-1-infected people on long-term antiretroviral therapy (ART).

The study, the investigators say, strongly suggest that defective or inert HIV-1 can remain in the liver macrophages for up to ten years without functioning as an HIV-1 "reservoir" that can replicate the virus at high levels.

But the finding, they say, also suggests that HIV-1 treatment strategies that only or mostly focus on these macrophages in a search for a cure might need to shift more heavily to other cell types more likely to serve as active reservoirs of the virus.

A report of the findings was published online on Sept. 10 and in the Oct. issue of the Journal of Clinical Investigation.

"Our study was the first, to our knowledge, in which purified liver tissue macrophages from HIV-1 infected people taking ART directly tested the idea that tissue macrophages are a long-lived active HIV-1 reservoir," says Ashwin Balagopal, M.D., an associate professor in the Division of Infectious Diseases at the Johns Hopkins University School of Medicine.

According to the U.S. Centers for Disease Control and Prevention (CDC), 36.7 million people worldwide and 1.1 million people in the U.S. are infected with HIV-1. Commonly, ART is successfully used to suppress the replication of HIV-1 and stop or control the progression of acquired immunodeficiency syndrome (AIDS) in humans. The virus infects the body's immune system cells, commonly forming a persistent, and reservoir in humans in so-called resting memory CD4+ T white blood cells. Macrophages work with T cells normally to envelop and clear tissues of microbes and debris.

The inability to completely wipe out pools of infectious HIV-1 has for decades frustrated efforts to completely cure the infection. And it means that the interruption or discontinuation of ART at any time re-activates HIV-1 replication, spreading the virus to new cells.
As a result, Balagopal says, investigators are increasingly focused more specifically on the location and biology of these HIV-1 reservoirs.

To determine if liver macrophages were a true source of infection-capable HIV-1 reservoir after ART, liver tissue samples were taken from nine HIV-1 infected persons, seven of whom underwent liver transplantation at the Johns Hopkins Hospital and would have otherwise had their livers discarded. Eight of the nine persons were on ART for periods ranging from eight to 140 months.

The sample group included only adults whose demographic information is considered exempt from human subject research because all samples were obtained strictly for scientific reasons or post-mortem and would otherwise have been discarded. The Johns Hopkins School of Medicine institutional review approved this study protocol.

Using lab techniques that both measure HIV-1 containing T cells and separate out the liver macrophages, the researchers found HIV-1 to be present in the macrophages even after exposure to longstanding virus-suppressing ART.

However, Balagopal said that when his team tried to simulate virus "rebound" from the liver macrophages in the laboratory, they found only "fragments of HIV-1 in small quantities, without robust growth of full-length, infectious virus."

The researchers found that HIV-1 was in the liver macrophages of one subject who took ART for 11.7 years. They concluded that while liver macrophages might harbor HIV-1 for a long time, it's unlikely these viruses could continue an infection on their own, unlikely to function as a reservoir, because the viruses were not able to replicate.

Balagopal cautioned that their study results still affirm the need to address liver macrophage infection, because even if inert, these cells may be able to produce portions of viral proteins that can misdirect the immune system.

"These results contribute an important piece in our efforts to understand the role of non-T cells, such as macrophages, as HIV-1 cellular reservoirs in individuals on long-term ART, but also may help the research community focus on additional cure strategies," Abraham Kandathil, Ph.D., a research associate in the Division of Infectious Diseases at Johns Hopkins University School of Medicine who performed all of the key experiments.

In the future, Kandathil says, more research is needed to determine if the inert HIV-1 infected liver macrophages have any functional significance in people taking ART because expression of defective HIV-1 proteins can confuse the immune system and cause tissue inflammation.

"To find a comprehensive HIV-1 cure, it's important to identify all of the relevant HIV-1 reservoirs in the body, since it's possible that the virus hides in the DNA of numerous cell types and each may require different strategies to get a cure," says Balagopal.

Balagopal noted that their study was limited by the small number of liver macrophages and human samples studied, as well as the small number of CD4+ T cells in the liver cell cultures that may have prevented the researchers' ability to detect them.


Source: https://www.sciencedaily.com/releases/2018/10/181001110210.htm

Saturday, 27 October 2018

Standard treatment for common STD doesn't eliminate parasite in some women

A new study led by an infectious disease epidemiologist at Tulane University School of Public Health and Tropical Medicine could change the way doctors treat a common sexually transmitted disease.

Professor Patricia Kissinger and a team of researchers found the recommended single dose of medication isn't enough to eliminate trichomoniasis, the most common curable STD, which can cause serious birth complications and make people more susceptible to HIV. Results of the research are published in Lancet Infectious Diseases.

Globally, an estimated 143 million new cases of trichomoniasis among women occur each year and most do not have symptoms, yet the infection is causing unseen problems. The recommended treatment for more than three decades has been a single dose of the antibiotics metronidazole or tinidazole.

The researchers recruited more than 600 women for the randomized trial in New Orleans; Jackson, Mississippi; and Birmingham, Alabama. Half the women took a single dose of metronidazole and the other half received treatment over seven days.

Kissinger and her team found the women who received multiple doses of the treatment were half as likely to still have the infection after taking all the medication compared to women who only took a single dose.

"There about 3.7 million new cases of trichomoniasis each year in the United States," Kissinger said. "That means a lot of women have not been getting inadequate treatment for many decades."

Trichomoniasis can cause preterm delivery in pregnant women and babies born to infected mothers are more likely to have low birth weight. The parasite can also increase the risk of getting or spreading HIV.

Kissinger believes the CDC will change its treatment recommendations because of the results of this study.

"We need evidence-based interventions to improve health," Kissinger says. "We can no longer do something because it's what we've always done. I hope that this study will help to change the recommendations so that women can get the proper treatment for this common curable STD."

Source: https://www.sciencedaily.com/releases/2018/10/181007084044.htm

Wednesday, 17 October 2018

During HIV infection, antibody can block B cells from fighting pathogens

For the first time, scientists have shown that in certain people living with HIV, a type of antibody called immunoglobulin G3 (IgG3) stops the immune system's B cells from doing their normal job of fighting pathogens. This phenomenon appears to be one way the body tries to reduce the potentially damaging effects of immune-system hyperactivity caused by the presence of HIV, according to the investigators, but in so doing, it also impairs normal immune function.

The research was led by scientists in the Laboratory of Immunoregulation and the Laboratory of Immunogenetics at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health.

The investigators made their discovery by analyzing blood samples from 83 HIV-uninfected, anonymous donors and 108 people who were living with HIV at various stages of infection. The people living with HIV came from a variety of racial and ethnic backgrounds. Some of these people were being treated for their infection, while others had not yet begun therapy.

The scientists observed that IgG3 appeared on the surface of B cells only under certain conditions. It appeared in people living with HIV, but not in HIV-uninfected people. Also, IgG3 predominantly appeared on B cells of people of African American or black African decent during the chronic phase of untreated HIV infection when the virus was not adequately controlled.

A site on B cells called the B-cell receptor normally binds to foreign entities such as pathogens. This binding stimulates the B cell to produce many copies of the antibody form of the receptor, which can trap a pathogen and mark it for destruction. The scientists found that IgG3 short-circuits this process in certain people living with HIV by docking on the B-cell receptor, blocking it from adequately responding to the pathogen or other intended target. The researchers also demonstrated how other components of the immune system contribute to IgG3 interference with normal B-cell function during HIV infection. Finally, they showed that IgG3 stops binding to B-cell receptors when a chronically infected person starts treatment that controls the virus, illustrating that the IgG3 activity is directly linked to the presence of HIV during chronic infection.

Source: https://www.sciencedaily.com/releases/2018/08/180813125236.htm

Monday, 8 October 2018

HIV RNA expression inhibitors may restore immune function in HIV-infected individuals

Immune activation and inflammation persist in most treated HIV-infected individuals and is associated with excess risk of mortality and morbidity. A new study by Boston University School of Medicine (BUSM) researchers suggests that use of HIV RNA expression inhibitors as adjunct therapy might diminish atypical inflammation and restore immune function in HIV-infected individuals on combination antiretroviral therapy (cART).

HIV-1-infected individuals have excess risk of developing non-AIDS complications such as cardiovascular atherosclerosis, neurocognitive dysfunctions, non-AIDS cancers, osteoporosis, and renal disorders. Systemic chronic immune activation has been postulated to lead to these non-AIDS complications.


Despite long-term viral suppression by cART, it has remained unclear how chronic inflammation is induced in HIV-infected individuals. In this study, BUSM researchers identified a mechanism of HIV-1-induced chronic immune activation and T cell dysfunction. In studies performed with primary human macrophages and T cells, they found that persistent infection of macrophages with HIV-1 and expression of intron-containing HIV-1 RNA alone even in the absence of infectious virus production lead to induction of type I interferon (IFN-I)-dependent pro-inflammatory responses and immune exhaustion of co-cultured T cells. They believe that these findings might provide an explanation for the observed chronic inflammation-associated morbidities in HIV-infected individuals who are on cART.

"We hope our study will broaden knowledge of host-HIV interactions and might help to reduce inflammation-associated disorders caused by chronic viral infections," said Rahm Gummuluru, PhD, corresponding author and associate professor of microbiology.

Source: https://www.sciencedaily.com/releases/2018/08/180827102648.htm

Submit your abstract here: https://std-hiv-aids.cmesociety.com/abstract-submission and join us at STD 2018 event taking place at Toronto, Canada on December 03-04, 2018.