News
Canadian cord-blood procedure passes key milestone in cancer trial
Researchers behind a made-in-Canada technology for multiplying the number of stem cells that can be derived from donated cord blood say they are ready to move on to the next phase in their effort to prove the technology can save lives.
Stem cells harvested from the umbilical cord blood of newborns are often favoured for transplants into adults because they can be more easily matched to recipients with less chance of complications. The problem is that there are often too few stem cells in a single cord-blood donation to help an adult patient.
But researchers have found a way to increase the stem cells from a single unit of cord blood by 35 times in a seven-day period. It’s this “expanded” form of cord blood that is now being tested in the Phase I/II clinical trial.
The overall survival rate after 12 months for patients who received the expanded cord transplant is currently 75 per cent, compared with 60 per cent for conventional cord transplants. Dr. Cohen and her collaborators now hope to launch a second clinical trial for high-risk leukemia patients who would otherwise have a very low chance of survival.
The basis of the technology is a small molecule, dubbed UM171, discovered by Guy Sauvageau and Anne Marinier at the University of Montreal. The molecule binds to cells and keeps new blood cells from specializing. Instead, they remain stem cells, and continue to proliferate until they are harvested from a laboratory medium. After they are injected into a patient, the stem cells take up residence and can generate all the cell types that are required to restore a healthy blood stream.
Finally, there’s a way to keep syphilis growing in the lab
For more than a century, scientists have tried to grow Treponema pallidum, the corkscrew-shaped bacterium that causes syphilis. But the stubborn spirochete has refused to thrive any place outside of a human or rabbit for more than 18 days. That doesn’t give researchers much time to study it.
“I’ve basically spent my entire career watching these organisms die,” says microbiologist Steven Norris, of the University of Texas Health Science Center at Houston. Until now. Norris and colleagues have cooked up a new recipe that keeps the bacteria alive for months, they report June 26 in mBio.
“We know very little about the organism,” Norris says. Being able to study it long-term in a dish could lead to better treatments for the millions infected worldwide and pave the way for the development of a vaccine to prevent the sexually transmitted disease.
First, the team tried “the kitchen sink approach,” testing between 10 and 20 mixes of nutrients and additives. No luck.
Then, inspiration — from the bacteria that causes Lyme disease — struck. Although Borrelia burgdorferi and T. pallidum behave differently and cause different diseases, the two have similar spiral structures. Maybe they would grow in the same medium. That logic paid off. CMRL 1066, a brothy complex of sugars and vitamins favored by the Lyme spirochete, has helped keep T. pallidum alive for almost eight months, Norris says.
Each week, he gets a thrill as he moves the multiplying bacteria to a fresh version of the medium. “It’s still a surprise to us that the organisms are growing,” he says.
$20 Blood Test Could Contribute to Global HBV Elimination
An international research team has devised a simple $20 blood test that could be used widely in low-income and middle-income countries (LMICs) to help determine which patients with hepatitis B require immediate treatment. The affordable test is based on measurements of hepatitis B virus e antigen (HBeAg), and levels of the liver enzyme alanine aminotransferase (ALT), to generate a diagnostic score, which the researchers say is as effective as existing, far more complicated, and expensive methods for assessing treatment eligibility.
The team, headed by scientists at the Pasteur Institute in Paris, Imperial College London, and the Medical Research Council (MRC) Unit The Gambia at the London School of Hygiene & Tropical Medicine, devised the score using data from more than 800 hepatitis B patients in The Gambia who were part of the PROLIFICA (Prevention of Liver Fibrosis and Cancer in Africa) study. They subsequently validated the diagnostic assay in cohorts of African patients in other countries.
“These results show that this simple and inexpensive test could be an accurate way to diagnose patients in need of hepatitis B treatment in countries with limited resources,” suggests Imperial's Maud Lemoine, Ph.D., who is co-author of the team’s study in the Journal of Hepatology, and who works with the MRC The Gambia Unit. “This could potentially help diagnose and subsequently treat thousands of people across Africa." Dr. Lemoine is also a member of the World Health Organization (WHO) guideline development group for the management of chronic hepatitis B/C.
The researchers, including colleagues in organizations and institutions in Africa and Europe, describe their results in a paper entitled “Development of a Simple Score Based on HBeAg and ALT for Selecting Patients for HBV Treatment in Africa.”
Clinical Chemistry
Emerging diabetes biomarkers offer new insights
Currently, blood glucose and hemoglobin A1c are the standard measures for the diagnosis and monitoring of diabetes. There has recently been increasing interest in nontraditional diabetes biomarkers, including fructosamine, glycated serum protein (GSP), glycated albumin (GA), and 1,5 anhydroglucitol (1,5 AG). Recent studies suggest that expanded use of these tests has the potential to improve diabetes care, as these assays overcome the limitations of HbA1c in some patients, while providing additional insight into shorter-term glycemic control and improving risk stratification for diabetes and its complications.
Glycated serum protein (glycated albumin)
Blood glucose also reacts with serum proteins via a slow, non-revisable Maillard reaction to form glycated serum protein (GSP). GSP is used for monitoring average blood glucose levels over the past two to three weeks, making it more useful for showing problems with control in the short term than HbA1c.
Fructosamine
In the literature, glycated serum protein (GSP) is also known as fructosamine. Fructosamine is traditionally measured by a non-specific chemical method using nitroblue tetrazolium (NBT) that is interfered with by various reducing substances in patient samples.
1,5 anhydroglucitol
1,5 anhydroglucitol (AG) correlates with post-meal hyperglycemia and reflects trends over a period of one to two weeks. Unlike the glycated hemoglobin and glycated serum proteins, 1,5 AG does not reflect an average blood glucose but rather reflects hyperglycemia and glycemic variability.
Be sure to click on the article title above to read more about these biomarkers.
Transfusion Medicine
The Re-emergence of Cold-Stored Platelets
WHY IS THE MEDICAL COMMUNITY (RE)-INTERESTED IN COLD-STORED PLATELETS?
A: In most healthcare settings, the treatment of choice for hypovolemic shock involves administering individual blood components—red cells, plasma, and platelets (PLTs)—proportionally to reflect their constitution in whole blood. In our practice, we previously abandoned using cold-stored PLTs (CS-PLTs) stored at 4°C, in part because studies show CS-PLTs are cleared from circulation faster than room temperature PLTs (RT-PLTs) stored at 22°C. However, although RT-PLTs may be more useful prophylactically in patients with thrombocytopenia, recent research has revealed that cold-induced storage lesions alter the metabolic and functional profile of PLTs such that they effectively curtail hemorrhage.
In light of these findings, healthcare institutions should tailor two different therapeutic strategies for CS-PLTs and RT-PLTs, respectively, based on specific clinical situations. This shift in transfusion practice could impact laboratory technologists cross-trained to work in both clinical labs and blood banks—a role that is becoming more common as many healthcare organizations move toward increased integration. A rise in CS-PLT usage will also have implications for labs that perform infectious diseases testing for blood banks.
WHAT IMPLICATIONS DOES CS-PLT TRANSFUSION HAVE FOR PATIENT TESTING?
A: Given the clinical indication for CS-PLTs, providers should perform a global analysis of acute traumatic coagulopathy when determining whether or not to transfuse a patient with CS-PLTs. The best test for this purpose is point-of-care thromboelastography, which interrogates the entire coagulation system and produces a tracing that identifies abnormal parameters that targeted blood component therapy could correct. The latter information is particularly important when making treatment decisions regarding CS-PLTs because PLTs play a central role in hemostasis after injury, yet are especially prone to acquiring both quantitative and qualitative defects in trauma. Thromboelastography could also be used to monitor resuscitation with CS-PLTs, which otherwise demonstrate a relatively normal functional profile.
Microbiology
New Findings on Bacteria in Female Bladders
Scientists and physicians at Loyola University Chicago and Loyola Medicine were the first to publish groundbreaking research that debunked the common belief that urine in healthy women is sterile.
Expanding on this finding, a new study published in Nature Communications has found that the bladder not only contains bacteria, but the microbes are similar to those found in the vagina. The new finding could lead to improved diagnostic tests and treatments for urinary tract infections and other urinary tract disorders.
It's not surprising the microbiota of the bladder and vagina are similar, since the organs are connected by the urethra. It appears that bacteria travel between the bladder and the vagina, effectively creating one microbiota niche. Urination provides an obvious way for bacteria to travel from the bladder to the vagina. But it's a mystery how bacteria could travel from the vagina to the bladder, especially since most of the bacteria examined in the study lack features such as flagella (whip-like structures) or pili (grappling hooks) that would enable them to move.
The new study found that the microbial sharing between the vaginal and bladder microbiota includes pathogens such as E. coli and S. anginosus as well as beneficial bacteria such as L. iners and L. crispatus.
Researchers suggested that beneficial bacteria residing in both the bladder and vagina could provide protection against urinary infections. This insight "should alter the way we view the bacteria of the female pelvic floor both by enabling further research and by providing new diagnostic and treatment options for urinary tract infections, urgency urinary incontinence and other associated urinary tract disorders," researchers wrote.
Anatomic Pathology
An examination of two critical IHC biomarkers
The detection of cervical intraepithelial neoplasia (CIN) is of increasing importance to cervical cancer screening, and has been fundamental to the overall decrease in the rate of cervical cancer incidence in the United States and around the world. The most common method for investigating CIN levels is immunohistochemistry (IHC). As has been shown in the literature, p16 and Ki-67 have been the leading biomarkers for high-risk HPV infections, which can lead to cancers of the cervix. Infections of HPV genotypes 16, 18, 31, 33, and 51 have been shown to be the leading causes of cervical cancer, and it has further been shown that there is a significant difference in diagnostic result when scoring between a CIN1 sample and a known negative. In this article, we will show how histologists and pathologists can help detect and identify CIN with these two critical biomarkers.
Since 1993, when p16 was first identified as a cyclin-dependent kinase inhibitor, this tumor suppressor protein has gained near-universal recognition among pathologists and oncologists alike. p16 was first implicated in human cancer cell lines through genomic analysis; researchers observed that p16 was frequently mutated, which suggested an important role in cancer development. Liggett and Sidrasky1 showed that in tumors, p16 can be inactivated by homozygous mutation, methylation of the promoter, or a point mutation. Furthermore, it has been suggested that the deletion of p16 is an early event in the progression of cancer, because the deletion of one copy of the gene is found in pre-cancerous cells. However, the expression of p16 is increased under abnormal situations, yet this increase doesn’t result in the suppression of cancer because p16 protein is inactive. Interestingly, under pre-cancerous conditions (CIN1-CIN3), p16 is upregulated and used as a biomarker for the detection of cervical cancer.
While p16 can suppress tumor progression, tumor growth and proliferation are dependent on another key transcription factor, Ki-67. During cellular interphase, Ki-67 is exclusively found in the nucleus, which gives the advantage of making it easy to “spot” in an IHC stain. Ki-67 is present during active phases of the cell cycle (G1, S, G2, and mitosis), but is absent from resting cells. During tumorigenesis and cell growth, Ki67 is unregulated, therefore mediating the uncontrolled cell growth. These facts make Ki-67 an antigen of choice when evaluating the growth fraction of a patient’s tissue section. The approximate fraction of Ki-67 positive cells has been shown to correlate with the clinical diagnostic result. A higher percentage of proliferating cells indicates a fast-growing tumor, while a low number of Ki-67 positive cells usually indicates a pre-cancerous lesion or an early-stage cancer.2
In a routine clinical lab, p16 and Ki-67 IHC tests are often run together, side-by-side, to allow pathologists to have a full understanding of the extent of a patient’s diagnostic and prognostic outcomes. While p16 scoring can commonly be used to identify the grade or progression of the cancerous tissue, Ki-67 is used to measure the rate of cell proliferation. Combining the two offers a superior diagnostic result when compared with p16 alone or Ki-67 alone. This is reflected very well in the literature, as Zhong et al found that p16 and Ki-67 expression significantly increased with disease progression (p16, P < 0.001; Ki-67, P < 0.001).3 Clearly, p16 and Ki-67 are useful in the evaluation of progression of cervical dysplasia. Together, they are a powerful tool for evaluating cancer progression.
Safety
Keeping the laboratory environment clean and safe
Lab directors should conduct audits of their department’s physical environment to identify safety hazards specific to their lab. Such audits typically do not need to interfere with the day-to-day lab processes, and they should be performed on a regular basis, at least monthly. Many changes can occur in a laboratory at any time, such as the movement of instruments, the placement of new equipment, or even the movement and stocking of lab supplies, and the implications of such changes for safety should be recognized.
When checking for physical environment safety, look to see that aisles are clear of boxes or other obstructions, especially if the pathway leads to a fire evacuation route. Loose wires from computers and keyboards need to be properly tied up. Make sure that lab floors are cleaned regularly; the U.S. Centers for Disease Control and Prevention (CDC) recommends that lab floors be wet-mopped at least daily in a biohazard area. Also, make sure anti-fatigue mats on the floor are replaced on a regular basis so that wear does not create slip or trip hazards. In histology areas, be sure to keep paraffin wax build-up from occurring on walkways in order to prevent dangerous falls. Use scrapers or other implements to remove any wax build-up as it occurs.
Ensure that laboratory safety equipment such as emergency eyewashes, showers, and fire extinguishers are unobstructed at all times. It is important to make sure there is easy access to bloodborne pathogen and chemical spill response kits. Electrical panels in the department should have three feet of clearance in front of them. Check all lab electric cords as well for fraying or other damage. Simple movement of equipment can easily damage a cord, and exposed wiring can be a cause of laboratory fires. Ensure that compressed gas tanks are secured to prevent tipping.
Cluttered lab work benches can also include hazards for workers. A messy workspace can contain hidden dangers such as contaminated sharps, infectious materials, and even unknown chemical hazards if there are unlabeled materials. Lab areas should be dusted regularly as well. Dust may contain molds and other air contaminants that can potentially interfere with laboratory testing, particularly in a microbiology laboratory. That is one reason why electric fans should not be used in a lab setting. Fans in the lab can circulate those air contaminants. Fans also interfere with safety airflow devices such as chemical fume hoods or biological safety cabinets, and they can even interfere with the lab room air flow that is maintained for staff protection.
Research
Autism blood test: One step closer
Following research published last year, a new paper outlines the further success of a diagnostic blood test for autism. The results could help to diagnose the condition at a younger age. Designing a reliable diagnostic test for Autism Spectrum Disorder (ASD) is a challenge that a number of institutions have taken up. One such institution is the Rensselaer Polytechnic Institute in Troy, NY.
Instead of looking for one single chemical to measure, the researchers — led by Prof. Juergen Hahn — used a big data approach and searched for patterns in metabolites.
In 2017, the researchers had their first success. They analyzed blood from 149 people with an ASD diagnosis, assessing each sample for levels of 24 metabolites. The chemicals were all related to two particular cellular pathways: the methionine cycle, and the transsulfuration pathway. Having done this, the scientists were able to create a test that could correctly identify more than 96 percent of ASD cases within the group that they had recruited. Recently, the same team set out to replicate its findings in a new dataset.
They assessed data from 154 children with ASD, taken by researchers from the Arkansas Children's Research Institute in Little Rock. This time, however, they only had access to information on 22 of the 24 metabolic markers they had used in the last trial.
Their results were published this month in the journal Bioengineering and Translational Medicine, and they are encouraging. When they applied the algorithm, it predicted ASD correctly in 88 percent of cases. While 88 percent is an impressive result, it is lower than the success rate from the previous studies. Prof. Hahn thinks that this is because the two missing metabolites were shown to be strong indicators in the last study. However, the results are still exciting.
Thank you!
We appreciate that you have taken the time to read LabBuzz. This is a CSMLS venture to provide relevant medical laboratory news to its members.
We need your help to grow this newsletter! Please pass along the subscription link to any colleague you think would benefit from hearing about med lab news.