In one of the most significant moments in the history of xenotransplantation, Towana Looney, a 54-year-old woman from Alabama became the first human to live for 130 days with a gene-edited pig kidney. Her journey has now ended with the organ's removal, but it yet remains an essential landmark in the field of medicine, especially in the search for viable animal-to-human transplants.

What Actually Happened That Led To The Xenotransplantation?

Towana Looney underwent the groundbreaking surgery on November 25, 2023, at NYU Langone Health. She had been on dialysis since 2016 and was ineligible for a human kidney transplant due to her immune system being highly sensitized, meaning it would likely reject a human organ. As a result, she volunteered to participate in an experimental xenotransplant procedure using a genetically modified pig kidney.

The transplant initially worked well. Looney even referred to herself as “superwoman,” noting that she felt better than she had in years. However, on April 4, 2024, after more than four months, her body began rejecting the organ, and doctors decided to remove it. She is now back on dialysis and recovering at home in Gadsden, Alabama.

Why Was The Pig Kidney Removed?

The decision made to remove the kidney came from the safety concerns as she developed an infection, which had been tied to her earlier dialysis treatment. It required doctors to reduce her immune-suppressing medicines. Around the same time, her immune system began reactivating, possibly triggering the rejection. Rather than risking a stronger dose of anti-rejection drugs—which could have caused further complications—her doctors chose to remove the kidney.

“We did the safe thing,” said Dr. Robert Montgomery, Looney’s surgeon and a leading figure in xenotransplantation. He emphasized that Looney wasn’t worse off than she had been before the transplant and, in fact, had benefited from 130 days free of dialysis.

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What Is Xenotransplantation?

Xenotransplantation is the process of transplanting organs or tissues between different species—in this case, from pigs to humans. Scientists are modifying pigs so their organs resemble human ones more closely, in hopes of addressing the severe shortage of donor organs.

Currently, more than 100,000 people in the U.S. are waiting for organ transplants, the majority needing kidneys. Thousands die every year waiting. If successful, pig organs could help close this gap.

Looney’s case is part of a broader effort to test pig organ viability in people who are not terminally ill. Previously, four other U.S. patients had received pig organs—two hearts and two kidneys—but none of those organs lasted longer than two months, and all recipients eventually died due to pre-existing health issues.

What Is Going To Happen Next?

Despite the setback, researchers are hopeful. In fact, the news is that a man in New Hampshire who received a pig kidney in January is doing well. More clinical trials are also expected to begin this summer to give a better answer on where we stand with xenotransplantation. Chinese researchers have also reported success with a recent pig kidney transplant.

One of the major ongoing challenges is determining the right combination of immune-suppressing drugs to prevent different types of organ rejection without increasing infection risk. As Dr. Tatsuo Kawai from Massachusetts General Hospital noted, “When we have more experience, we’ll know what kind of immunosuppression is really necessary for xenotransplant.”

It is no surprise that when anyone looks for innovation and technology, the first name that comes to their mind is of Japan. In yet another breakthrough, Japan may be too close to invent artificial blood. Last year, it was declared that Japan will begin its clinical study of artificial red blood cells that can be stored for transfusion in times of emergency. This was released by Nara Medical University.

It is now in the process of developing artificial blood cells and aims to put these artificial cells into practical use by 2030. This would be world's first.

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Why Is This Happening?

Japan is battling a shrinking population, where the older population dominates the younger ones. In 2024, Japan had a record of high 36.25 million people aged 65 or older, representing 29.3% of the total population. This indicates a significantly larger proportion of elderly citizens as compared to the young population.

This has led to a shortage of blood supply, as older people cannot donate blood. As per the Red Cross Society, donors up to 65 years of age can donate blood. While there is no upper age limit, you must be in good health to meet other eligibility criteria.

A 1987 study published in JAMA titled Blood Donation by the Elderly: Clinical and Policy Considerations, notes that it is far more feasible for individuals within the age bracket of 66 to donate blood. Another comparative study from 2019, published in Biomedical Excellence for Safer Transfusion Collaborative (BEST) Investigators noted that while there is no exclusion for older donors, the limit is solely based on their safety.

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Another reason why this clinical study is being conducted is because white blood cells obtained form already donated blood can only be stored for less than a month at low temperatures. However, the artificial cells can be stored for two years at room temperature. As the artificial cells are also made from any blood type, they can be used without confirming a patients' blood type and could be administered even during transportation by ambulance, confirmed the researchers.

The university also said that if no side effects are confirmed with 400ml of administration, the trial will shift to examine the treatment's efficacy and safety.

Who Is Leading This Study?

A team led by Professor Hiromi Sakai of the Nara Medical University is leading this study. The approach involves extracting hemoglobin, which is the oxygen carrying molecule in the red blood cells from expired donor blood, and then encasing it in a protective shell to create stable, virus-free artificial red blood cells.

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How Artificial Blood is Different From Donated Blood?

The main difference lies in the absence of blood type, which further eliminates the need for compatibility testing. This is what makes it invaluable in the case of emergency.

Professor Teruyuki Komatsu of Chuo University is also leading the artificial oxygen carrier study. This uses albumin-encased hemoglobin to stabilize blood pressure and treat conditions like hemorrhage and stroke. For now, animal studies have shown promising results.

How Is Artificial Blood Made?

The process usually starts with stem cells. This is where special cells are that can in fact develop into different types of cell in your body. This includes red blood cells, platelets, or even skin cells.

Scientists use a specific type of cell called the haematopoietic stem cells, which can produce all types of blood cells, including the WBC, RBC, and platelets. They are then placed in a lab setting to turn these stem cells into blood cells.

Cedric Ghevaert, who is the professor of transfusion medicine at the University of Cambridge, explained that scientists are then able to "gene edit" the stem cells to boost blood production and remove blood group markers, as reported in Aljazeera.

Have Others Tried To Make Artificial Blood?

The United States military has invested $46m in developing ErythroMer, a synthetic blood substitute designed to be universally compatible and stable without refrigeration. The product is still under research.

In 2022, a clinical trial in the UK also marked a breakthrough where laboratory-grown red blood cells were transfused into human volunteers to assess their safety standards and longevity, as reports Aljazeera.

In 2013, the U.S. Defense Advanced Research Projects Agency (DARPA) estimated that producing a single unit of lab-grown blood cost over $90,000. Thanks to improvements in production techniques, that cost has now dropped to under $5,000 per unit. In contrast, hospitals in the U.S. paid an average of just $215 per unit for donated red blood cells in 2019.

In another news, a new device Tendyne transcatheter mitral valve replacement (TVMR) system has been approved by the US Food and Drug Administration (FDA) for the treatment for patients who are suffering from severe mitral annular calcification (MAC). The prominent player in this is Abbott Laboratories who earned the FDA approval for the device.

What Is the TVMR system?

The Tendyne system is designated for those who are at high risk for traditional open-heart surgery. It helps with those with mitral valve disease, as it can cause debilitating symptoms like chest pains, shortness of breath, and dizziness due to heart's impaired ability to pump blood effectively.

As per experts of valve diseases, the challenges that patients with mitral annular calcification face could be reduced with the help of Tendyne system.

It is also designed for its adaptability to various patient anatomies. Furthermore, the surgery is minimally invasive and involves only a small incision in the chest. The valve is also responsible for repositionable and retrievable during the implantation process, ensuring optimal placement.

What Is Mitral Annular Calcification?

As per a 2020 study published in the Indian Journal of Thoracic and Cardiovascular Surgery, titled Mitral annular calcification: challenges and future perspectives, MAC is a chronic degenerative process that implies calcification on the mitral support structure.

It was first described in 1908 by Bonninger, as associated with complete heart block. Dewitzky presented detailed pathologic descriptions of 36 cases and demonstrated the close resemblance to a similar process that had been described in the aortic valve in 1904 by Monckeberg. Yater and Cornell in 1935 histopathologically demonstrated extension of a calcific mass into the Bundle of His leading to heart block.

What exactly happens in this condition is that there is a buildup of calcium deposits, along the mitral annulus, the fibrous ring that supports the mitral valve. It is also common among older individuals and is often discovered incidentally during imaging for other reasons. While people with MAC may not have symptoms, it can progress to cause issues like mitral stenosis, which is narrowing of the valve or mitral regurgitation, which means leaking of the valve.

Why It Happens?

As it is a degenerative process, it is thus potentially linked to factors like aging, atherosclerosis, and other cardiovascular risk factors. It is also linked to conditions like hypertension, diabetes, and chronic kidney disease.

Severe MAC can often lead to serious complications like heart failure, stroke, or even death.

Diagnosis

It is typically diagnosed through imaging technique like echocardiography or cardiac CT. Echocardiography can show the calcifications as bright, reflective structures on the ultrasound.

Texas is experiencing the nation’s worst measles outbreak in over 20 years. More than 700 people have been infected so far, with dozens hospitalized and two unvaccinated children dying due to complications. This surge in a disease once declared eliminated in the U.S. has raised alarms among public health experts and lawmakers alike.

The outbreak began earlier this year in West Texas’ Mennonite communities, where vaccine hesitancy is common. It soon spread to other areas with low immunization rates, highlighting the vulnerability of unvaccinated populations. Despite existing vaccine requirements for schoolchildren in Texas, exemptions for religious, personal, or medical reasons remain legal and increasingly popular.

Controversial New Legislation

Even as the measles outbreak shows signs of slowing, Texas lawmakers have passed a bill that would make it significantly easier for parents to exempt their children from vaccinations required for school enrollment—vaccines that protect against diseases like measles, whooping cough, polio, and hepatitis A and B.

Under current law, parents must request exemption forms from the state health department by mail, a process that can take weeks. The new bill, now awaiting Republican Governor Greg Abbott’s signature, allows families to download the forms online, though they must still be notarized before being submitted to schools.

Supporters argue that the bill merely streamlines a process that is already legal. “This bill is not about whether vaccines are good or bad,” said Jackie Schlegel, founder of Texans for Medical Freedom. “It's about government efficiency and keeping kids in schools.”

Health Officials Push Back

Public health experts are sounding the alarm. Rekha Lakshmanan, chief strategy officer for the Immunization Partnership, warned lawmakers that simplifying exemption access could have deadly consequences. “If this bill becomes law, Texas is likely to see more illness, more death and higher health care costs for families and businesses,” she testified.

She also pointed to the outbreak itself as a warning. “It is the canary in the coal mine screaming at the top of its lungs.”

Texas’ vaccine exemption rates have surged in recent years. The Department of State Health Services received nearly 153,000 exemption requests for the 2023-24 school year, almost double the number from five years ago.

A Broader Trend

Texas is not alone. Across the country, conservative lawmakers have introduced hundreds of vaccine-related bills in 2025, many of which weaken vaccine mandates. Brent Ewig of the Association of Immunization Managers said the group is tracking nearly 600 such bills this year, the majority of which are not pro-vaccine.

This shift follows growing anti-vaccine sentiment sparked by the COVID-19 pandemic and amplified by figures like Robert F. Kennedy Jr., who was recently appointed U.S. Secretary of Health and Human Services.

Future Legal Challenges and Proposals

Another bill pending in the Texas Senate could allow lawsuits against vaccine makers if their products cause harm, provided they advertise in Texas. This bill has faced strong opposition from business groups, including the Texas Association of Manufacturers.

The proposal is led by Rep. Shelley Luther, known for defying COVID restrictions in 2020. Her push represents a broader movement questioning vaccine safety and government mandates.

As Texas continues to recover from its ongoing outbreak, critics fear that easing exemption rules may put even more children and communities at risk.