In 1938, Louis K. Diamond, MD, and Kenneth Blackfan, MD, at Boston Children’s Hospital described a severe congenital anemia that they termed “hypoplastic” (literally, “underdeveloped”) because of the bone marrow’s inability to produce mature, functioning red blood cells. Eighty years later, the multiple genetic origins of this highly rare disease, now known as Diamond-Blackfan anemia, or DBA, are finally coming into view.
Hematopoietic stem cells (HSCs) have long been regarded as the granddaddy of all blood cells. After we’re born, these multipotent cells give rise to all our cell lineages: lymphoid, myeloid and erythroid cells. Hematologists have long focused on capturing HSCs’ emergence in the embryo, hoping to recreate the process in the lab to provide a source of therapeutic blood cells.
But in the embryo, oddly enough, blood development unfolds differently. The first blood cells to show up are already partly differentiated. These so-called “committed progenitors” give rise only to erythroid and myeloid cells — not lymphoid cells like the immune system’s B and T lymphocytes.
Researchers in the lab of George Q. Daley, MD, PhD, part of Boston Children’s Hospital’s Stem Cell Research program, wanted to know why. Does nature deliberately suppress blood cell multipotency in early embryonic development? And could this offer clues about how to reinstate multipotency and more readily generate different blood cell types? …
Genetic labels, or “barcodes,” are shedding new light on the natural process of blood development and immune-cell production, finds a study published in Nature this week. It was led by Fernando Camargo, PhD, and first author Alejo Rodriguez Fraticelli, PhD, at Boston Children’s Hospital’s Stem Cell Research Program, the Harvard Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute.
Most of what we know about blood production is through observing what happens when blood stem and progenitor cells are transplanted into an animal. To observe what happens “in the wild,” researchers went in and tagged the blood stem and progenitor cells of mice, using genetic elements called transposons. This allowed them to track how the cells differentiated into five kinds of blood cells (above: megakaryocytes, erythroid cells, granulocytes, monocytes and B-cell progenitors). …
When Brenden Whittaker of Columbus, Ohio, the first patient treated with gene therapy for chronic granulomatous disease (CGD), showed successful engraftment last winter, the gene therapy team lifted glasses for a celebratory toast. The wine they sipped was no ordinary wine. The 2012 Bordeaux blend came from an award-winning California vineyard owned and operated by Robert Baehner, MD, a pioneering pediatric hematologist with ties to Dana-Farber/Boston Children’s Cancer and Blood Disorders Center.
Decades before, Baehner had done fundamental research in CGD, an inherited immune system disorder that occurs when phagocytes, white blood cells that normally help the body fight infection, cannot kill the germs they ingest and thus cannot protect the body from bacterial and fungal infections.
Children with CGD are often healthy at birth, but develop severe infections in infancy and early childhood from bacteria that would cause mild disease or no illness at all in a healthy child. This was true for Whittaker. Diagnosed with CGD when he was 1, his disease became increasingly severe, forcing him to quit school several years ago. …
Peers describe David G. Nathan, MD, president emeritus of Dana-Farber Cancer Institute and physician-in-chief emeritus of Boston Children’s Hospital, as a “a once-in-a-generation leader,” a “giant” and a “proverbial triple threat” combining clinical care, research and teaching leadership.
Nathan, whose commitment to pediatric medicine spans nearly six decades, received a standing ovation when presented with Boston Children’s inaugural Lifetime Impact Award Friday afternoon at the hospital’s Global Pediatric Innovation Summit + Awards.
The Lifetime Impact Award recognizes a clinician and/or researcher who has devoted his or her career to accelerating innovation in pediatric medicine and who has made extraordinary and sustained leadership contributions. …
One thing that most people don’t realize about stem cell transplants (also called bone marrow or hematopoietic stem cell transplants) is that for patients, the transplant itself is probably the easiest part of the process. The grueling part is the preparation for a transplant, called conditioning.
I had to admit that I didn’t. I’ve always thought of sickle cell—a painful and debilitating disease caused by an inherited mutation that makes red blood cells stiffen into a characteristic sickled shape—as a chronic disease to be managed, not one that could be cured.
I’m not alone in that belief. Lehmann often asks this question when she give talks for medical students, residents and other physicians. Their reaction is puzzlement, then a shaking of heads.
If there’s one thing most patients with sickle cell disease will agree on, it’s that sickle cell hurts. A lot.
The characteristic rigid, sticky, C-shaped red blood cells of this inherited disease tend to get stuck in the small blood vessels of the body. If so many get stuck in a vessel that they cut off blood flow, the body sends out a warning signal in the form of searing pain that doctors call a pain or vaso-occlusive crisis (at least, that’s the historic view; more on that in a minute). The pain can happen anywhere in the body, but most often occurs in the bones of the arms, legs, chest and spine.
Preventing flare-ups—and stopping them when they happen—is a major part of the care plan for any patient with sickle cell. Right now doctors try to avoid pain crises largely by diluting a patient’s blood with fluids or transfusions, thereby keeping the numbers of sickled cells relatively low.
What these treatments don’t do is tackle the pain directly. Doctors can use pain medications, but over time, patients can become tolerant to painkillers, requiring ever-larger doses. What’s needed is something that can stop the complex cascade of events that ignite a pain crisis. …
Sickle-cell anemia was the first disease to have its genetic cause identified, in the 1950s — a milestone in human genetics. Yet today, there’s just one FDA-approved drug, hydroxyurea, developed 20 years ago at Children’s. Though it’s a mainstay of treatment, reducing the frequency of severe pain, acute chest syndrome and the need for blood transfusions, it can cause toxicity, and about half of patients aren’t helped by it. Only a hematopoietic stem-cell transplant is curative.
Research on sickle-cell disease has generally been underfunded compared with other genetic diseases like cystic fibrosis that aren’t as common. But Children’s has been exploring new treatment approaches for decades, and two exciting possibilities have emerged. …