Author: microbiologybymadeline

If you or anyone you know has asthma, you may have heard of the drug Xolair (Omalizumab). Xolair is what is known as a monoclonal antibody drug. To explain how the drug works, understanding what a monoclonal antibody is is important. A monoclonal antibody is an antibody produced in vitro that only recognizes a single epitope on an antigen. Conversely, polyclonal antibodies recognize multiple epitopes of an antigen. Both are useful in various immunoassays; however, monoclonal antibodies also have great therapeutic use due to their specificity.  

Xolair is an injectable monoclonal antibody drug used against severe asthma that cannot be well managed by common medications such as inhaled corticosteroids. Most asthma results from an allergic reaction in the lower respiratory tract. Allergic reactions occur when a person has an antibody response to a harmless substance. When a person encounters an allergen, their body begins to produce IgE antibodies against that substance. The next time a person is exposed, the IgE antibodies on mast cells and basophils bind to the allergen and stimulate the release of proinflammatory mediators causing the allergic reaction. In this case, that inflammation occurs in the airways, causing what we know as asthma. Xolair is a monoclonal antibody that binds to free IgE, preventing it from attaching itself to mast cells and basophils, thus preventing immune response that causes an allergic reaction. 

This drug can be very beneficial to people who suffer from asthma. However, there are many possible side effects. 

Possible side effects include:

• Anaphylaxis
• Cancer
• Heart and circulation problems
• Parasitic infections
• Pain in arms and legs
• Dizziness
• Skin rash
• Bone fractures
• Pain or discomfort in ears
• Tiredness
• Headache
• Fever
• Sore throat
• Nausea and/or vomiting
• Nose bleeds

One of the biggest risks is severe allergic reaction leading to anaphylaxis. Due to this people who are given Xolair are monitored by their healthcare provider during and after they receive the injection. Another important side effect is that risk of parasitic infection is significantly increased while taking Xolair as IgE, which is used to fight off parasitic infections, is inactivated. Most of the side effects that occur when taken Xolair are thought to be a result of reduction of oral corticosteroids. It is thought increased risk of cancer may be due to the drug’s immunosuppressive activity.

We’ve all heard a lot about the COVID-19 tests in the news. But have you wondered how these tests are conducted and what exactly they are testing for? I know I was curious. After looking into it, I found that there are 2 major types of tests being used: polymerase chain reaction (PCR) and antibody testing. Let’s talk about some of the differences between the two.

As of now, the majority of tests being conducted are done by PCR. PCR allows for the detection of the RNA genome of the virus. Because this directly tests for the presence of the antigen, it indicates a current infection. The viral RNA will be present before symptoms even occur, allowing for very early detection. This is a benefit over antibody testing, as you don’t have to wait for the body to mount an immune response. However, PCR is labor intensive and there is a chance of receiving a false negative. 

Alternatively, an antibody test can be done by taking blood. The downside to antibody testing is that it takes some time for the body to make these antibodies after encountering the virus. When initially exposed, after a few days the body will begin to produce IgM antibodies; a week or so after that the body begins to make IgG antibodies instead. If a person were to test positive for only IgM, it means they were very recently infected and IgG has not yet been produced. IgM has a relatively short half life, so if a person tests positive for IgM AND IgG it means they recently started making IgG and were infected not too long ago. If a person tests positive for only IgG it means they were infected in the past and have probably recovered. However, we don’t currently know if a past infection indicates this person will be immune to reinfection in the future or how long that immunity might last. 

Clearly, both of these tests have their pros and cons. However, both are beneficial in letting people know that they need to self isolate to prevent further spread of the disease. Anyone testing positive with PCR, should self isolate even if they are asymptomatic as they can still spread the disease before symptoms begin to show. Detectable levels of IgM antibodies against COVID-19 also indicate active or recent infection with the potential to be contagious. With testing becoming more and more accessible in the United States, hopefully the spread of the disease will slow as more people are able to know if they have contracted it.

Every day I am amazed by how far medicine has come. Diseases that were once a death sentence are now able to be treated, giving so many people a second chance at life. One area of medicine I’ve always found particularly interesting is oncology. All of the therapies that have emerged in recent years really show how amazing modern medicine and technology are. Two treatments that showcase this include T-cell and dendritic cell therapy. 

Sometimes, T-cells are unable to recognize and destroy cancer cells. T-cell therapy involves removing T-cells from the patient’s blood. The T-cells are there alters to express chimeric antigen receptors (CAR), to better allow the T-cells to recognize cancer cells. The new CAR T-cells are then returned to the patient. The CAR T-cells are now able to multiply and target the cancer cells. This therapy is used to treat lymphoma. Side effects can include anemia, cytokine release syndrome, and neurologic problems including confusion, aphasia, seizures and more. This treatment has an 80% success rate, as of recent data. According to Drugs.com, Yescarta, the CAR T-cell therapy used in adults with lymphoma isn’t cheap, in the US it costs $373,000. Kymriah, the treatment used in children, costs even more at $475,000.

Dendritic cell therapy is another form of cancer treatment that utilizes the body’s own immune cells. Dendritic cells are used to present antigens that activate the body’s T-cells. Several methods have been discovered that work to improve antigen presentation to elicit more powerful immune responses against cancer cells. Dendritic cell vaccinations are an emerging treatment, which consist of injections of dendritic cells combined with tumor associated antigens. Dendritic cell vaccinations have been the subject of numerous clinical trials over the past 20 years with one being approved by the FDA in 2010 for advanced stage prostate cancer. This treatment is called Sipuleucel-T also known as Provenge. Provenge has an expected cost of $93,000 with a median survival of 4.1 months longer than men who did take the drug. Common side effects include headache, fever, fatigue, and nausea lasting only one to two days.

These therapies use the patients own cells and have considerably less side effects that chemotherapy. They offer great promise to those suffering from cancer and their loved ones. I just hope that in the future, the cost of these therapies will decrease to make them more accessible to the average person.

I think it goes without saying, things have changed a lot in the past few weeks. We are living in unprecedented times. Universities, retailers, restaurants, all closed. Chapel Hill now feels like a ghost town. We’ve all had to make changes in our schedules and routines. As a person who finds comfort in routine, the past couple weeks have been tough. 

During a normal week, I spend countless hours working in various coffee shops around Chapel Hill and Carrboro. Normally, if I’m not sleeping, I’m not home. Learning to work from home has been a big challenge. It’s hard to stay focused when I’m always two feet away from Netflix and the fridge. Having a cat who like to sit on your computer doesn’t help either (pictured below). 

Figuring out how to do school work from home has definitely been difficult, but I’ve managed. For me the hardest part of the current situation is being out of a job. I work as a bartender, and the restaurant I work in closed a couple weeks ago for the foreseeable future. But knowing that staying home is quite literally saving peoples lives, I know I can get through this.

I hate to complain about my situation when I am safe and healthy and there are people out there still working every day, risking their own lives to help others. My family works in healthcare and they have been working around the clock to do everything they can to get through this. Seeing doctors and nurses put the lives of other people first is truly selfless and is part of what inspires me to go into medicine. I can only hope that everyone else is out there doing their part by staying home so life can go back to normal, sooner rather than later.

Sexually transmitted diseases are something most people don’t like to talk about, but the stigma needs to end and we need to get the conversation started. According to a press release by the CDC, cases of syphilis, gonorrhea, and chlamydia reached an all time high in 2018. Syphilis, gonorrhea, and chlamydia are all infections that are curable by antibiotics (for now). However, increasing antibiotic resistance makes the rising rates of these diseases especially concerning. 

Gonorrhea is caused by the bacteria Neisseria gonorrhoeae. Untreated gonorrhea can lead to pelvic inflammatory disease, infertility, and ectopic pregnancies, among other complications. Being able to successfully treat this disease is vital, and we are losing that ability. In the 1990’s ciprofloxacin, ceftriaxone, and cefixime were recommended to cure a gonorrhea infection. However, by the early 2000’s ciprofloxacin use was discontinued due to extensive resistance. Currently there is only one recommended first line treatment: ceftriaxone, taken with azithromycin. However, it is reported that in recent years Gonorrhea’s susceptibility to azithromycin has decreased as well.

If this doesn’t scare you, it should. The idea that these diseases may not be treatable in coming years, means it’s time we need to start taking protecting ourselves more seriously. If you grew up in North Carolina like I did, sexual eduction in school was pretty much nonexistent. It’s time to stop the stigma surrounding sexual health and have more conversations. Check out this link here, for some great information about how to best protect yourself and get all the facts you may have missed in school.

Everyone has been prescribed antibiotics at one point or another. But are people really educated about the drugs they are taking? Personally, I think the average American has a lot to learn. We all know people (or maybe you are one of those people) who run to the doctor as soon as they feel a cold coming on and beg for antibiotics. Let me tell you now, do not be this person! Through the incorrect and overuse of antibiotics, we as a society have created a major problem. These important life saving drugs are being taken for granted, and are now losing their effectiveness. 

You may have heard the term “superbug” thrown around in the news recently. Superbugs are disease causing bacteria that have become resistant to the drugs once used to kill them. As we continue to use antibiotics, the bacteria are adapting and finding ways to protect themselves from the drugs created to destroy them. When we take antibiotics for a bacterial infection, the “weak” bacteria die, but those able to resist the effects of the drug survive and multiply. These resistant bacteria are spreading, making more people sick, and we don’t have drugs that work against them anymore. The CDC estimates 35,000 die each year from antibiotic resistant bacteria. If we continue using antibiotics the way we do, this number will only grow. 

 It’s time to start taking antibiotic resistance seriously. This is a problem that is happening now. Anyone can be infected by an antibiotic resistant bacteria, even you or me. And there may not be anything we can do to fight it. Not only do health care providers need to become more responsible in their prescriptions, but we need to become more responsible as consumers. We need to educate our friends and family members about antibiotics and when and how we should be using them. For more information, check out this 2019 report by the CDC. 

Here are some things you can do to protect yourself for antibiotic resistant infections:

-Wash your hands often and carry hand sanitizer
-Do not take antibiotics for a virus (they will NOT work!)
-When you are prescribed antibiotics, make sure you take them for the directed amount of time, never quit early!
-Prepare food safely
-Practice safe sex (gonorrhea, a common STI, is becoming resistant to many drugs)
-Be cautious traveling abroad (make sure you are consuming safe foods and water and get any recommended vaccinations)
-Stay educated and aware!

If you didn’t read my previous post on the flu, I am a big advocate of vaccines. If you need yet another reason to be convinced vaccines are a good thing, consider the fact that you’ve never gotten polio (and probably can’t think of one person who has). Polio is a fantastic example of how effective vaccines can be. Polio is a highly contagious virus that attacks the nervous system and in severe cases can lead to paralysis. Thanks to two vaccinations and a global effort, polio has been nearly eradicated worldwide.

 Polio enters the body orally and infects the cells that line the throat and intestinal tract, from there it can invade the bloodstream. Once in the bloodstream, it can invade nerve cells and cause the disease poliomyelitis. 3 serotypes of polio exist, any of which can cause the disease. In the 1950s, the Salk vaccine was developed, a vaccine consisting of inactivated virus particles of all 3 types. This vaccine is called the inactivated polio vaccine (IPV). This vaccine successfully lowered the rate of disease, but unfortunately requires multiple injections. In 1961, a new vaccine called the Sabin vaccine became available, also known as the oral polio vaccine (OPV). This is an attenuated vaccine that replicates in cells that line the throat and respiratory tract. 

The OPV is predominately used today in the global effort to eradicate polio as it is cheap and does not require as much skill to administer, as no syringes are needed. It is more effective than the IPV at interrupting person to person transmission. Thanks to the Global Polio Eradication Initiative, polio has been nearly eradicated almost every country in the world. According to the Center for Infectious Disease Research and Policy, as of October 2019, Wild Poliovirus Type 3 has been completely eradicated worldwide. This means 2 out of the 3 types of polio are now completely eradicated. Wild Poliovirus Type 1 cases persist in a few countries, which can be tracked weekly here. As the global effort to fight polio continues, I am hopeful Type 1 can be eradicated as well. If this doesn’t speak to the benefits of vaccines, I don’t know what does.

In the past few years, the microbiome has become a hot topic. Even if you’re not an experienced scientist, I would bet you’ve read something or another about the bacteria growing in your gut. Unfortunately, we live in a day and age where lots of misinformation is spread online. Bad pop science articles and health conspiracy theories are shared on Facebook every day (we all have that one relative). That’s why I am here to share some recent and reliable facts about the microbiome!

It has been known that the bacteria that live inside us affect our health. Every day, more research is being done to demonstrate that these microbes may affect us more than we initially thought. The microbiome starts to develop as an infant passes through the birth canal and continues to develop until around the age of 3. These early years for a child are critical as the acquired composition of gut microbiota will persist into adulthood. Disruptions in the development of a healthy microbiome in early childhood can be linked to higher risk of obesity, diabetes, allergies, and asthma along with various other chronic conditions. This may be explained by what is called the “hygiene hypothesis” which suggests that exposure to various microorganisms protects children by contributing to their immune system; thus being overly clean may contribute to diseases such as asthma or allergies. (Disclaimer: Please do not use this hypothesis as an excuse to not wash your hands!)

Not only does your microbiota affect your immune system, new evidence shows that it may affect your behavior and mood as well. A study published in January 2020 demonstrated that a child’s gut microbiota can be linked to their behavior. Other studies conducted in the last year have shown that people with mental health disorders such as depression, bipolar disorder, and schizophrenia show significant differences in their gut microbiome. These are just a few of the ways our microbiota impacts our lives. We have come a long way in what we know about the microbiome and what it can do for us, with new research being published all the time. In coming years our knowledge will only grow, hopefully leading to the development of therapeutics for some of the health problems mentioned above.

In the midst of panic surrounding the coronavirus, people have seemingly forgotten about another deadly infectious disease that’s circulating the United States. The flu. Maybe it’s because the flu goes around every year and people are familiar with it, people tend to underestimate its danger. According to the CDC, this season alone, an estimated 10,000 to 25,000 deaths have occurred from the flu. It seems to me, this is what people need to be more worried about catching. 

Typical flu symptoms include fever, headache, muscle aches, chills, and a sore throat. Most people recover after a couple weeks. However, severe complications that may be life threatening can occur. Elderly people, children under 5, pregnant women, and people with chronic medical conditions are at high risk for developing complications. This is why getting vaccinated is so important. The exact effectiveness of this year’s flu shot is not known yet but studies show that the flu vaccine can reduce the risk of illness by 40 to 60%.

If you’re reading this and have yet to get a flu shot, you may be wondering, is there still time? Is it too late? It is recommended to get the flu vaccine by the end of October before flu season peaks. However, it is possible for flu season to last as late as May. As long as the virus is circulating getting vaccinated can be beneficial, even in February. But just know, it takes up to 2 weeks to become effective. If you have yet to get the flu shot, I recommended going as soon as possible. Its takes 5 minutes, its often free, and better to be safe than sorry. 

Bonus fact: All of the flu vaccines made this year are egg free and safe for people with egg allergies! Go get your flu shot!

At this point most people have heard someone say that vaccines cause autism. But have you ever wondered where this (very false) claim came from? In 1998, former doctor Andrew Wakefield published a study in the Lancet suggesting that the measles, mumps, and rubella (MMR) vaccine is linked to developmental disorders, including autism, in children. The study consisted of a small sample size of 11 boys and 1 girl, who had been referred to a pediatric gastroenterology unit for abdominal pain and diarrhea along with loss of acquired skills, including language. Wakefield reported an association between gastrointestinal diseases and developmental regression in these children, 8 of who had received the MMR vaccine. The study was uncontrolled and the claims made were merely speculations.

Despite the flawed science (read more here), this paper received wild publicity that led to a drop in MMR vaccination rates due to parents fear of their children developing autism as a result of the vaccine. It wasn’t long before multiple studies were published refuting the link between autism and the MMR vaccine. Soon after, 10 out of the 12 co-authors of the study retracted the interpretation of the data, claiming the data was insufficient. This came with a report a from the Lancet that Wakefield had failed to disclose financial interests. Wakefield had been funded by lawyers who were representing parents in lawsuits against vaccine producing companies. In 2010, the paper was retracted completely. Wakefield and his colleagues were found guilty of ethical violations and scientific misrepresentation. Wakefield was found guilty of deliberate fraud for financial gain, including falsifying facts and only picking data that suited the case.

Although this paper was retracted and multiple studies have proven no link between vaccines and autism, many parents are still wary of vaccinating their children and this paper is often still cited by members of the anti-vaxx movement. In the past few years, the anti-vaxx movement has lead to serious outbreaks of diseases that had been nearly eradicated in the United States.  According to the CDC, in 2019, the greatest number of measles cases were reported since 1992. The majority of these cases had occurred in unvaccinated people. The fear of vaccines has lead to illness and deaths have could have been easily prevented. Moral of the story: be wary of bad science and vaccinate your kids.