Medical scientists step up search for allergy treatment

Domestic pets are one of the causes of allergic reactions. PHOTO | FOTOSEARCH
Domestic pets are one of the causes of allergic reactions. PHOTO | FOTOSEARCH 

It took Racheal Atieno three years to discover why her two-year-old daughter always sneezed each time she placed her on a couch in the sitting room.

She would clean and dust all the seats because the sneezing only occurred when her daughter was in the sitting room.

“My daughter would sneeze and afterwards her nose would block and she would experience difficulty in breathing,” says Ms Atieno.

She says every week she would be in hospital or chemist buying allergy drugs. She visited many paediatricians, but the problem persisted.
Little did she know that her daughter was allergic to cat fur.

She stopped taking her daughter to the sitting room. One day, she left the baby on the bed and the girl started sneezing. “I noticed that our cat had moved next to her. This took me time to realise,” she says.

According to Dr Walter Otieno, cat allergy is caused by a type of protein present in the fur. The allergens are airborne and are easily inhaled by humans. After inhaling the allergens, people react and experience a variety of symptoms.

“For children, the symptoms are worse because after sneezing their noses are blocked and breathing becomes very difficult,” says Dr Otieno.
Cat allergy is very dangerous because it causes shortness of breath and wheezing.

“We normally prescribe drugs for people who suffer from allergies. Unfortunately, you probably can’t stop cat allergies or cure them if the cat is still in the house,” says Dr Otieno.

However, he says, there are many cat allergy solutions that reduce allergy symptoms. “Brush and bathe your cat to lose fur so that you can throw it in the garbage rather than have the fur flying around your house. There are special brushes that you can buy that pull the loose fur,” recommends Dr Otieno.

He also advised that cats should be kept out of the bedroom and sitting rooms for eight hours a day.

“The best remedy was to keep away the cat but most people cannot because they have made with the cats,” he said.

Experts say that allergies — including a number of food-related ones — have increased in recent years with people suffering brain damage or near death situations after experiencing severe allergic attacks. Just a few weeks ago, a UK TV producer suffered brain damage and she is still being treated for it.

“The problem of allergies is growing worldwide, and symptoms range from an inconvenient rash to severe toxic reaction. Allergens can range from cats and dogs, to pollen and even nuts and metals,” said one BBC report some years back.

Researchers are seeking a cure for allergies. Recently, medical records have shown that people can tolerate peanuts if treated with certain probiotic —medicine containing peanut protein — for a while. The probiotic used is called lactobacillus rhamnosus, which has been key to preventing certain allergic symptoms.

In the case of frequent sneezing, according to scientists, there is a particular part of people’s immune system that should be blamed.

A new study on a specific group of cells that cause allergic reactions has been launched. This will also help the scientists determine not only why some people have allergies but also how to block them.

“It’s exciting for those of us who are looking at potential ways to treat allergic diseases,” says Thomas Casale, an allergist and immunologist at the University of South Florida in Tampa.

Allergies stem from mistaken identity when some of our immune cells respond to some substances.

The allergies could be as a result of inhaling pollen, mould spores, cat fur, perfumes and certain foods.

Researchers have identified culprits that cause allergies. It belongs to a group of T-cells known as TH2 cells — though not all are responsible.

Some of the cells guard us against parasites and other invaders. However, sorting the beneficial TH2 cells from the rogue ones has proved difficult.

In the study, researchers led by T-cell biologist Erik Wambre and immunologist William Kwok of the Benaroya Research Institute in Seattle, Washington DC, obtained blood samples from patients who were sensitive to pollen from alder trees — a common cause of winter and spring allergies.

An allergic patient’s TH2 cells recognise and respond to an allergen because they carry receptors, proteins that match allergen molecules.

Along with receptors, TH2 cells are dotted with marker proteins. Like sports fans wearing their favourite team’s jersey, immune cells proclaim their identity with these marker proteins.

The researchers analysed the tagged cells to determine their combination of markers. Compared with other TH2 cells, one group spotted more copies of two marker proteins and fewer copies of four others.

The researchers found that TH2A cells remained distinct, even after several cellular generations.

“When these cells are born, they are born to be pathogenic,” Wambre says.

The findings were reported in Science Translational Medicine.

According to the findings, the cells were abundant in the blood of patients with allergies to a variety of triggers, including cat fur, grass, pollen and house dust mites. But they were absent from the blood of people who weren’t sensitive.

The researchers also tested patients undergoing an experimental treatment called oral immunotherapy to alleviate their peanut allergies.

“Over about 20 weeks, the participants receive larger and larger doses of allergy-inducing peanut proteins, and this repeated exposure eventually allows them to tolerate peanuts. We saw a dramatic decrease in TH2A cells after the success of the treatment,” Wambre says.

The number of these cells in the patients that reacted to peanuts fell by about 90 per cent.

“People with allergies make this specific separation of T cells that probably lead to allergic symptoms.”

“The work could ultimately benefit patients through new treatments and better ways to monitor the disease, says immunologist Andrew Luster of Massachusetts General Hospital in Charlestown.

He said the scientists could assess trials of oral immunotherapy which attempts to quell patients’ allergies with edible doses of food allergens by tracking which treatments were eliminating TH2A cells.

“We could still determine what molecular signals steer certain T cells to become TH2A cells, then we may be able to develop ways to prevent formation of the cells,” he says

By this treatment, we will also prevent allergies that entail sniffling and scratching.

“This would be like break through, many children are allergic to so many things, once the formation of the cell is determined, then we are safe,” said Dr Otieno.