Sickle cell patients and others who need long-term blood transfusions provided by clinical laboratories and others would benefit most from successfully lab-grown blood
Administering lab-developed red blood cells in humans in a clinical study conducted in the United Kingdom (UK) is being hailed as a significant step forward in efforts to supplement the supply of whole blood through the development of synthetic blood products. Of interest to those clinical laboratory managers overseeing hospital blood banking services, researchers were able to create this new blood product from normal blood pints collected from donors.
What caused this clinical study to gain wider attention is the fact that previous attempts to create synthetic whole blood products have proved to be unsuccessful. For that reason, this new research has raised hopes that lab-grown blood may be just around the corner.
The initiative, known as RESTORE, is a joint research project conducted by scientists from the UK’s:
According to the researchers, it is the first such clinical trial performed in the world. Partial funding for this clinical study was provided by an NIHR grant, according to an NHS press release.
Most hospital laboratories also manage a blood bank. Thus, this breakthrough will be of interest to many clinical laboratory managers and blood bankers who are concerned about the shortage of blood products. Plus, blood products are quite expensive. This research could develop solutions that both ease the tight supply of blood and lower the cost of these critical products while improving patient care.
“This research, backed by government investment, represents a breakthrough for patients and means treatment could be transformed for those with diseases including sickle cell,” said Neil O’Brien (above), Minister of State for Health, in an NHS press release. “Once again this shows the UK is leading the world when it comes to scientific innovation and collaboration while delivering high quality care to those who need it the most,” he added. If the lab-grown products prove clinically viable, medical laboratories in the UK may soon suffer less from a shortage of available blood. (Photo copyright: UK Parliament.)
Manufacturing Blood from Stem Cells
“This world-leading research lays the groundwork for the manufacture of red blood cells that can safely be used to transfuse people with disorders like sickle cell,” hematologist Farrukh Shah, MD, Medical Director Transfusion, NHS Blood and Transplant, told BBC News. “The need for normal blood donations to provide the vast majority of blood will remain. But the potential for this work to benefit hard-to-transfuse patients is very significant.”
The process of manufacturing blood cells starts with a normal donation of a pint of blood. The researchers then use magnetic beads to single out flexible stem cells that can become red blood cells. Those flexible stem cells are grown in large quantities in the lab and then guided to transform into red blood cells.
“This challenging and exciting trial is a huge stepping stone for manufacturing blood from stem cells,” said Ashley Toye, PhD, Professor of Cell Biology at the University of Bristol in the NHS press release. “This is the first-time lab grown blood from an allogeneic donor has been transfused and we are excited to see how well the cells perform at the end of the clinical trial.”
The process to create the lab-grown blood cells takes about three weeks, and a pool of approximately half a million stem cells can result in 50 billion red blood cells. These cells are then clarified further to reap about 15 billion red blood cells that are at the optimum level to transplant into a human patient.
“Some blood groups are extremely rare, to the point that only 10 people in a country can donate blood,” Toye told BBC News. “We want to make as much blood as possible in the future, so the vision in my head is a room full of machines producing it continually from a normal blood donation.”
Transforming Care for Patients Who Need Long-term Blood Transfusions
To date, only two patients have taken part in the clinical trial. Next, the researchers plan to perform two mini transfusions on 10 volunteers at least four months apart. One transfusion will contain traditional donated red blood cells and the other will consist of the lab-grown cells. This experiment will show which blood cells last longer in the body. The findings could ultimately allow a patient to receive fewer transfusions and prevent iron overload, which can be a side effect of blood transfusions.
“We hope our lab-grown red blood cells will last longer than those that come from blood donors,” said Cédric Ghevaert, MD, Senior Lecturer in Transfusion Medicine at the University of Cambridge, in the NHS press release. “If our trial—the first such in the world—is successful, it will mean that patients who currently require regular long-term blood transfusions will need fewer transfusions in the future, helping transform their care.”
More research and clinical trials will be necessary to validate the efficacy and safety of these lab-grown blood products. However, such a breakthrough could potentially revolutionize treatments for patients with blood disorders, complex transfusion needs, and rare blood types, as well as reduce healthcare costs and curb blood shortages.
At the same time, this technology would also contribute to expanding the supply of useful blood products, a development that would be welcomed by those pathologists and clinical laboratory professionals overseeing the blood banks in their respective hospitals and integrated delivery networks (IDNs).
‘Prime editing’ is what researchers are calling the proof-of-concept research that promises improved diagnostics and more effective treatments for patients with genetic defects
Known as Prime Editing, the scientists developed this technique as a more accurate way to edit Deoxyribonucleic acid (DNA). In a paper published in Nature, the authors claim prime editing has the potential to correct up to 89% of disease-causing genetic variations. They also claim prime editing is more powerful, precise, and flexible than CRISPR.
The research paper describes prime editing as a “versatile and precise genome editing method that directly writes new genetic information into a specified DNA site using a catalytically impaired Cas9endonuclease fused to an engineered reverse transcriptase, programmed with a prime editing guide RNA (pegRNA) that both specifies the target site and encodes the desired edit.”
And a Harvard Gazette article states, “Prime editing differs from previous genome-editing systems in that it uses RNA to direct the insertion of new DNA sequences in human cells.”
Assuming further research and clinical studies confirm the
viability of this technology, clinical laboratories would have a new diagnostic
service line that could become a significant proportion of a lab’s specimen
volume and test mix.
In that e-briefing we wrote that Liu “has led a team of scientists in the development of a gene-editing protein delivery system that uses cationic lipids and works on animal and human cells. The new delivery method is as effective as protein delivery via DNA and has significantly higher specificity. If developed, this technology could open the door to routine use of genome analysis, worked up by the clinical laboratory, as one element in therapeutic decision-making.”
Now, Liu has taken that development even further.
“A major aspiration in the molecular life sciences is the ability to precisely make any change to the genome in any location. We think prime editing brings us closer to that goal,” David Liu, PhD (above), Director of the Merkin Institute of Transformative Technologies in Healthcare at the Broad Institute, told The Harvard Gazette. “We’re not aware of another editing technology in mammalian cells that offers this level of versatility and precision with so few byproducts.” (Photo copyright: Broad Institute.)
Cell Division Not Necessary
CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats. It is considered the most advanced gene editing technology available. However, it has one drawback not found in Prime Editing—CRISPR relies on a cell’s ability to divide to generate desired alterations in DNA—prime editing does not.
This means prime editing could be used to repair genetic mutations in cells that do not always divide, such as cells in the human nervous system. Another advantage of prime editing is that it does not cut both strands of the DNA double helix. This lowers the risk of making unintended, potentially dangerous changes to a patient’s DNA.
The researchers claim prime editing can eradicate long lengths of disease-causing DNA and insert curative DNA to repair dangerous mutations. These feats, they say, can be accomplished without triggering genome responses introduced by other forms of CRISPR that may be potentially harmful.
“Prime editors are more like word processors capable of
searching for targeted DNA sequences and precisely replacing them with edited
DNA strands,” Liu told NPR.
The scientists involved in the study have used prime editing to perform over 175 edits in human cells. In the test lab, they have succeeded in repairing genetic mutations that cause both Sickle Cell Anemia (SCA) and Tay-Sachs disease, NPR reported.
“Prime editing is really a step—and potentially a significant step—towards this long-term aspiration of the field in which we are trying to be able to make just about any kind of DNA change that anyone wants at just about any site in the human genome,” Liu told News Medical.
Additional Research Required, but Results are Promising
Prime editing is very new and warrants further
investigation. The researchers plan to continue their work on the technology by
performing additional testing and exploring delivery mechanisms that could lead
to human therapeutic applications.
“Prime editing should be tested and optimized in as many cell types as researchers are interested in editing. Our initial study showed prime editing in four human cancer cell lines, as well as in post-mitotic primary mouse cortical neurons,” Liu told STAT. “The efficiency of prime editing varied quite a bit across these cell types, so illuminating the cell-type and cell-state determinants of prime editing outcomes is one focus of our current efforts.”
Although further research and clinical studies are needed to
confirm the viability of prime editing, clinical laboratories could benefit
from this technology. It’s worth watching.
CRISPR-Cas9 connection to cancer prompts research to investigate different approaches to gene editing
Dark Daily has covered CRISPR-Cas9 many times in previous e-briefings. Since its discovery, CRISPR, or Clustered Regularly Interspaced Short Palindromic Repeats, has been at the root of astonishing breakthroughs in genetic research. It appears to fulfill precision medicine goals for patients with conditions caused by genetic mutations and has anatomic pathologists, along with the entire scientific world, abuzz with the possibilities such a tool could bring to diagnostic medicine.
All of this research has contributed to a deeper understanding of how cells function. However, as is often the case with new technologies, unforeseen and problematic questions also have arisen.
“Here we report significant on-target mutagenesis, such as large deletions and more complex genomic rearrangements at the targeted sites in mouse embryonic stem cells, mouse hematopoietic progenitors, and a human differentiated cell line,” wrote the authors in their introduction.
Another study, this one conducted by biomedical researches at Cambridge, Mass., and published in Nature, describes possible toxicity caused by Cas9.
“Our results indicate that Cas9 toxicity creates an obstacle to the high-throughput use of CRISPR-Cas9 for genome engineering and screening in hPSCs [human pluripotent stem cells]. Moreover, as hPSCs can acquire P53 mutations, cell replacement therapies using CRISPR-Cas9-enginereed hPSCs should proceed with caution, and such engineered hPSCs should be monitored for P53 function.”
Essentially what both groups of researchers found is that CRISPR-Cas9 cuts through the double helix of DNA, which the cell responds to as it would any injury. A gene called p53 then directs a cellular “first-aid kit” to the “injury” site that either initiates self-destruction of the cell or repairs the DNA.
Therefore, in some instances, CRISPR-Cas9 is inefficient because the repaired cells continue to function. And, the repair process involves the p53 gene. P53 mutations have been implicated in ovarian, colorectal, lung, pancreatic, stomach, liver, and breast cancers.
Though important, some experts are downplaying the significance of the findings.
Erik Sontheimer, PhD (above), Professor, RNA Therapeutics Institute, at the University of Massachusetts Medical School, told Scientific American that the two studies are important, but not show-stoppers. “This is something that bears paying attention to, but I don’t think it’s a deal-breaker,” he said. (Photo copyright: University of Massachusetts.)
“It’s something we need to pay attention to, especially as CRISPR expands to more diseases. We need to do the work and make sure edited cells returned to patients don’t become cancerous,” Sam Kulkarni, PhD, CEO of CRISPR Therapeutics, told Scientific American.
Both studies are preliminary. The implications, however, is in how genes that have become corrupted are used.
A team from the Salk Institute may have found a solution. They are investigating a different enzyme—Cas13d—which, in conjunction with CRISPR would target RNA rather than DNA. “DNA is constant, but what’s always changing are the RNA messages that are copied from the DNA. Being able to modulate those messages by directly controlling the RNA has important implications for influencing a cell’s fate,” Silvana Konermann, PhD, a Howard Hughes Medical Institute (HHMI) Hanna Gray Fellow and member of the research team at Salk, said in a news release.
The Salk team published their findings in the journal Cell. The paper describes how “scientists from the Salk Institute are reporting for the first time the detailed molecular structure of CRISPR-Cas13d, a promising enzyme for emerging RNA-editing technology. They were able to visualize the enzyme thanks to cryo-electron microscopy (cryo-EM), a cutting-edge technology that enables researchers to capture the structure of complex molecules in unprecedented detail.”
The researchers think that CRISPR-Cas13d may be a way to make the process of gene editing more effective and allow for new strategies to emerge. Much like how CRISPR-Cas9 led to research into recording a cell’s history and to tools like SHERLOCK (Specific High-sensitivity Enzymatic Reporter unLOCKing), a new diagnostic tool that works with CRISPR and changed clinical laboratory diagnostics in a foundational way.
Each discovery will lead to more branches of inquiry and, hopefully, someday it will be possible to cure conditions like sickle cell anemia, dementia, and cystic fibrosis. Given the high expectations that CRISPR and related technologies can eventually be used to treat patients, pathologists and medical laboratory professionals will want to stay informed about future developments.
Most insurers still determine coverage on a case-by-case basis, but two major payers now have coverage policies that are helpful to clinical labs that perform WES
This is due to two reasons. First, researchers are identifying new ways to use whole exome sequencing to improve patient care. Second, the cost of whole genome sequencing continues to fall at a steady rate, making it ever more affordable to use in clinical settings.
As recently as 2009, WES was prohibitively expensive and there was little possibility that insurers would cover the cost of the test, as it was considered experimental. Now, however, evidence is mounting that it is an effective diagnostic tool. Therefore, more payers are announcing coverage for WES for an expanding number of diagnostic purposes. (more…)
In a trial, the lens-free microscope invention from the UCLA California Nano Systems Institute enabled a board-certified pathologist to detect cancers and other cellular abnormalities at 99% accuracy
One of our favorite innovators is at it again, this time with a device that could eventually allow pathologists to use a device coupled with a smartphone to view cancer and other abnormalities at the cellular level.
At UCLA, Professor Aydogan Ozcan, Ph.D. is already well known for having invented attachments that use a smartphone’s camera to create a tiny, lens-free microscope. Now Ozcan, who is the Chancellor’s Professor of Electrical Engineering and Bioengineering at the UCLA Henry Samueli School of Engineering and Applied Science, has created an inexpensive smartphone device that produces holographic images of tissue samples that allow pathologists to view cancer and other abnormalities at the cellular level, according to a December 17, 2014, Science Translational Medicine (STM) article. (more…)
