Welcome to “This Week in Blood,” a weekly snapshot of the hottest
studies from each week’s issue of Blood,
the official journal of the American
Society of Hematology (ASH),
hand-picked by Blood Editor-in-Chief
Bob Löwenberg, MD, and Deputy Editor Nancy Berliner, MD. If you would like a
PDF copy of any of the manuscripts highlighted below or would like to request
an interview with the author, please email firstname.lastname@example.org.
Anti-protamine–heparin antibodies: incidence, clinical relevance and
pathogenesis, Bakchoul et al.
High incidence of antibodies to protamine and
protamine/heparin complexes in patients undergoing cardiopulmonary bypass,
Lee et al.
manuscripts in this week’s issue of Blood
report the unexpected finding that a significant proportion of patients
undergoing cardiopulmonary bypass develop antibodies to protamine. In the first
study, Bakchoul et al report that nearly 10 percent of patients had
anti-protamine antibodies at baseline, increasing to nearlay 27 percent within
10 days of bypass. Lee et al. report similar findings: 29 percent of
post-bypass patients developed antibodies within 30 days. Antibodies were more
common in patients with diabetes, and protamine heparin complexes cross-reacted
with protamine-containing insulin preparations. In most patients these antibodies
were clinically silent and declined over several months; however in a small
number of patients, the antibodies bound and activated platelets in the
presence of protamine. This may be a rare cause of unexplained thrombocytopenia
and thrombosis reminiscent of heparin-induced thrombocytopenia.
Perivascular support of human hematopoietic stem/progenitor cells,
Corselli et al.
It has been notoriously difficult to maintain and expand hematopoietic stem
cells (HSC) in vitro without the loss
of long-term repopulating capability. This loss of “stemness” has been
attributed to the absence of factors within the bone marrow niche that are
necessary for the support of these cells. In this week’s issue of Blood, Corselli and colleagues have
moved closer to overcoming this obstacle, reporting the isolation of a subset
of CD146+ perivascular cells that support HSCs in long-term culture, producing
cells that are consequently able to engraft in immunodeficient mice.
Remarkably, investigators report that CD146+ perivascular cells supporting HSCs
could also be isolated from non-hematopoietic adipose tissue.
Tumor promoting immune
suppressive myeloid derived suppressor cells in multiple myeloma
microenvironment, Görgün et al.
suppressor cells (MDSCs) are a myeloid subpopulation with an immunosuppressive
phenotype. In this week’s issue of Blood,
Görgün and colleagues report on studies characterizing MDSCs in multiple
myeloma. MDSCs were significantly increased in myeloma patients, where they
were demonstrated to induce myeloma cell growth and to suppress T-cell mediated
immune responses. Furthermore, myeloma cells could induce healthy donor blood
mononuclear cells to develop into MDSCs, providing a “feed-forward” loop
promoting tumor growth and protection from immune attack. This suggests that
manipulation of MDSCs may offer a novel therapeutic strategy of multiple
Reporters who wish to receive a copy of any of the manuscripts
highlighted above or would like to request an interview with the authors may
contact Andrea Slesinski at 202-552-4927 or email@example.com.
the most cited peer-reviewed publication in the field of hematology, is
available weekly in print and online. Blood is the official journal of
the American Society of Hematology (ASH) (www.hematology.org),
the world’s largest professional society concerned with the causes and
treatment of blood disorders.
ASH’s mission is to further the understanding, diagnosis, treatment, and
prevention of disorders affecting blood, bone marrow, and the immunologic,
hemostatic, and vascular systems by promoting research, clinical care,
education, training, and advocacy in hematology.
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