Day: January 15, 2021

Itching in Severe Eczema Uses a Different Pathway

A study shows that there are two molecular pathways for conveying sensations of itching, with the itching of severe eczema following an unexpected route.

In normal eczema, cells in the skin convey the itching sensation, releasing histamines. This can be blocked with antihistamines.

“Years ago, we used to think that itch and pain were carried along the same subway lines in the nerves to the brain, but it turned out they weren’t, and these new findings show there’s another pathway entirely that’s causing these episodes of acute itching in eczema patients,” said principal investigator Brian S Kim, MD, Washington University School of Medicine. “The itch can be maddening. Patients may rate their chronic itch at around a 5 on a scale of 10, but that goes up to 10 during acute itch flares. Now that we know those acute flares are being transmitted in an entirely different way, we can target that pathway, and maybe we can help those patients.”

With severe itching in eczema, different cells in the blood are activated, transmitting great quantities of non-histamine molecules which also convey the itching sensation. This renders antihistamines usesles in trying to control the itch. The discovery of this new pathway offers new possibilities for treating other conditions as well. Recent studies have tried to block Immunoglobulin E (IgE) in response to allergies.

“We’ve connected acute itching in eczema to allergic reactions transmitted by an entirely different population of cells,” explained Kim. “In patients who experience episodes of acute itching, their bodies react in the same way as in people with acute allergy. If we can block this pathway with drugs, it might represent a strategy for treating not only itch but other problems, including perhaps hay fever and asthma.”

The team found that when mice with eczema made IgE in response to environmental allergens, they began to itch. However, instead of activating mast cells which produced histamine, the IgE activated basophils (a kind of white blood cell), activating a different nerve pathway to normal itching.

The discovery that eczema is exacerbated by allergens may help people avoid severe itching episodes, as well has helping the development of new targets for treatment.

Source: News-Medical.Net

Journal information: Wang, F., et al, A basophil-neuronal axis promotes itch. Cell, 2021 doi.org/10.1016/j.cell.2020.12.033.

Stellenbosch Doctors Urge Patience on Ivermectin

The South African public should be patient and wait for data on Ivermectin’s effectiveness against COVID, according to Stellenbosch doctors, who urge patience. The doctors wrote an article published in the South African Medical Journal explaining that further studies need to be completed before ivermectin can be authorised for use.

A veterinarian parasiticide that may have relevant antiviral and anti-inflammatory properties, ivermectin has gathered considerable attention for possible use in COVID prophylaxis and treatment since a number of small trials appeared to show effectiveness. However, close examination shows that they are very weak. Doubts have been raised over whether the necessary concentrations used in vitro can be achieved in vivo.

In their article, the doctors noted that several large randomised controlled trials are underway, and the results of these will allow the possible effectiveness of ivermectin to be gauged. “Data for Ivermectin from larger RCTs are expected in early 2021,” the doctors wrote. “These data are very promising, showing large treatment effects and acceptable adverse effect profiles for ivermectin against Covid-19, especially when combined in meta-analyses.”

They pointed out that the hoped-for effectiveness of other medications had not been borne out. “As a recent example, the widely proclaimed benefits of hydroxychloroquine and chloroquine from observational studies proved to be unfounded in larger RCTs,” they wrote.

Ivermectin use has been banned by the government, to considerable resistance. A number of organisations have already demanded that ivermectin be administered as a COVID treatment, including Black First Land First, the New Economic Rights Alliance and AfriForum. Afriforum is contemplating legal action to have ivermectin authorised. These calls have come despite the South African Health Products Regulatory Authority (SAHPRA) repeatedly counselled against the use of ivermectin.

The doctors cautioned that although the data trends indicated a possible efficacy for ivermectin, the optimal dosage if effective still needed to be determined: “Higher than standard Ivermectin doses appear to be safe in humans, but at the time of writing there is still much uncertainty regarding the human dose required to achieve antiviral activity and a favourable benefit-to-risk balance.”

Source: IOL

Johnson & Johnson is Behind on Vaccine Production

Despite releasing promising data on its COVID vaccine, Johnson & Johnson may fall up to two months behind on its vaccine production schedule, Politico reported. The company is still committed to releasing the trial data on its 45 000 participants by the end of January to pave the way for approval.

If approved, as seems likely, the vaccine would be extremely beneficial for vaccination efforts as it would only require a single dose to confer protection and also would not require sub zero refrigeration, greatly simplifying vaccination efforts.

The company’s effort is part of the Operation Warp Speed initiative to vaccinate the US population as fast as possible, with a goal of vaccinating 80% of the country’s 330.7 million population by the end of June. The previous goal to distribute 20 million doses by the end of 2020 had already fallen short owing to insufficient production.

The co-director of Operation Warp Speed, Moncef Slaoui, hinted at a production slowdown, telling the media that the company was expecting to produce “single-digit million” doses by the second half of February. “We’re trying to make that number get as close to a double-digit number as possible, and then a larger number in March and a much larger number in April,” he added.

Johnson & Johnson had previously made a pledge to deliver 12 million doses by the end of February and as many as 100 million by June.

Despite the delay, there is good news in that initial data from 400 participants shows that the vaccine is safe and has a 90% efficacy in establishing antibodies, with immunity for most subjects established 29 days after the shot and lasting at least 57 days. Adverse reactions were reported to be be mild, and younger subjects were more likely to report them, with one subject experiencing a brief, mild fever.

Source: Politico