Occult alloimmunization to the D antigen (RhD) related to graft versus host disease and its treatment

Alloimmunization to red blood cell (RBC) antigens post-allogeneic stem cell transplantation (allo-SCT) appears to be quite rare. The D antigen (RhD) is considered the most immunogenic RBC antigen with possibly a third of RhD-negative individuals exposed to RhD-positive RBC transfusions becoming alloimmunized. Though variable, most are detectable within a year of exposure, and the median time between exposure and detection is estimated to be about a month. We report the detection of anti-D in an allogeneic bone marrow transplant (allo-BMT) recipient about five years following last exposure to RhD-positive RBC.

Planned Granulocyte Colony-Stimulating Factor Adversely Impacts Survival after Allogeneic Hematopoietic Cell Transplantation Performed with Thymoglobulin for Myeloid Malignancy

The in vivo depletion of recipient and donor T lymphocytes using antithymocyte globulin (ATG; Thymoglobulin) is widely adopted in allogeneic hematopoietic stem cell transplantation (HCT) to reduce the incidence of both graft failure and graft-versus-host disease (GVHD). However, excess toxicity to donor lymphocytes may hamper immune reconstitution, compromising antitumor effects and increasing infection. Granulocyte-colony stimulating factor (G-CSF) administered early after HCT may increase ATG-mediated lymphotoxicity. This study aimed to investigate the effect of an interaction between ATG and post-transplantation granulocyte colony-stimulating factor (G-CSF) on allogeneic HCT outcomes, using the Center for International Blood and Marrow Transplant Research (CIBMTR) registry. We studied patients age ≥18 years with acute myelogenous leukemia (AML) and myelodysplastic syndrome (MDS) who received Thymoglobulin-containing preparative regimens for HLA-matched sibling/unrelated or mismatched unrelated donor HCT between 2010 and 2018. The effect of planned G-CSF that was started between pretransplantation day 3 and post-transplantation day 12 was studied in comparison with transplantations that did not include G-CSF. Cox regression models were built to identify risk factors associated with outcomes at 1 year after transplantation. A total of 874 patients met the study eligibility criteria, of whom 459 (53%) received planned G-CSF. HCT with planned G-CSF was associated with a significantly increased risk for nonrelapse mortality (NRM) (hazard ratio [HR] 2.03; P <.0001; 21% versus 12%) compared to HCT without G-CSF. The 6-month incidence of viral infection was higher with G-CSF (56% versus 47%; P = .007), with a particular increase in Epstein-Barr virus infections (19% versus 11%; P = .002). The observed higher NRM with planned G-CSF led to lower overall survival (HR, 1.52; P = .0005; 61% versus 72%). There was no difference in GVHD risk between the treatment groups. We performed 2 subgroup analyses showing that our findings held true in patients age ≥50 years and in centers where G-CSF was used in some, but not all, patients. In allogeneic peripheral blood HCT performed with Thymoglobulin for AML and MDS, G-CSF administered early post-transplantation resulted in a 2-fold increase in NRM and a 10% absolute decrement in survival. The use of planned G-CSF in the early post-transplantation period should be carefully considered on an individual patient basis, weighing any perceived benefits against these risks.

Comparison of total body irradiation versus non-total body irradiation containing regimens for de novo acute myeloid leukemia in children

With limited data comparing hematopoietic cell transplant outcomes between myeloablative total body irradiation (TBI) containing and non-TBI regimens in children with de novo acute myeloid leukemia, the aim of this study was to compare transplant-outcomes between these regimens. Cox regression models were used to compare transplant-outcomes after TBI and non-TBI regimens in 624 children transplanted between 2008 and 2016. Thirty two percent (n=199) received TBI regimens whereas 68% (n=425) received non-TBI regimens. Five-year non-relapse mortality was higher with TBI regimens (22% vs. 11%, P<0.0001) but relapse was lower (23% vs. 37%, P<0.0001) compared to non-TBI regimens. Consequently, overall (62% vs. 60%, P=1.00) and leukemia-free survival (55% vs. 52%, P=0.42) did not differ between treatment groups. Grade 2-3 acute graft versus host disease was higher with TBI regimens (56% vs. 27%, P<0.0001) but not chronic graft versus host disease. The 3-year incidence of gonadal or growth hormone deficiency was higher with TBI regimens (24% vs. 8%, P<0.001) but there were no differences in late pulmonary, cardiac or renal impairment. In the absence of a survival advantage, the choice of TBI or non-TBI regimen merits careful consideration with the data favoring non-TBI regimens to limit the burden of morbidity associated with endocrine dysfunction.

Survival Trends in Infants Undergoing Allogeneic Hematopoietic Cell Transplant

IMPORTANCE

Studies demonstrating improved survival after allogeneic hematopoietic cell transplant generally exclude infants.

OBJECTIVE

To analyze overall survival trends and other outcomes among infants who undergo allogeneic hematopoietic cell transplant.

DESIGN, SETTING, AND PARTICIPANTS

In this cohort study, we used time-trend analysis to evaluate 3 periods: 2000 through 2004, 2005 through 2009, and 2010 through 2014. The study was conducted in a multicenter setting through the Center for International Blood and Marrow Transplant Research, which is made up of a voluntary working group of more than 450 transplant centers worldwide. Two groups of infants aged 1 year or younger in 2 cohorts were included: those with malignant conditions, such as leukemia, and those with nonmalignant disorders, including immunodeficiencies. Data analysis was conducted from July 2017 to December 2018.

EXPOSURES

Allogeneic hematopoietic cell transplant.

MAIN OUTCOMES AND MEASURES

Survival trends, disease relapse, and toxicity.

RESULTS

A total of 2498 infants with a median age of 7 months (range, <1-12 months) were included. In the nonmalignant cohort (n = 472), survival rates improved from the first to the second period (hazard ratio, 0.77 [95% CI, 0.63-0.93]; P = .007) but did not change after 2004. Compared with infants with nonmalignant diseases (n = 2026; 3-year overall survival: 2000-2004, 375/577 [65.0%]; 2005-2009, 503/699 [72.0%]; and 2010-2014, 555/750 [74.0%]), those with malignant conditions had poorer survival rates, without improvement over time (3-year overall survival: 2000-2004, 109/199 [54.8%]; 2005-2009, 104/161 [64.6%]; and 2010-2014, 66/112 [58.9%]). From 2000 through 2014, relapse rates increased in infants with malignant conditions (3-year relapse rate: 2000-2004, 19% [95% CI, 14%-25%]; 2005-2009, 23% [95% CI, 17%-30%]; 2010-2014, 36% [95% CI, 27%-46%]; P = .01). Sinusoidal obstruction syndrome was frequent, occurring with a cumulative incidence of 13% (95% CI, 11%-16%) of infants with nonmalignant diseases and 32% (95% CI, 22%-42%) of those with malignant diseases. Generally, recipients of human leukocyte antigen-identical sibling bone marrow grafts had the best outcomes.

CONCLUSIONS AND RELEVANCE

Survival rates have not improved for infants with malignant diseases over the 15-year study period. Infants with nonmalignant diseases had improved survival rates in the earlier but not the later study period. Higher relapses for the malignant cohort and toxicities for all infants remain significant challenges. Strategies to reduce relapse and toxicity and optimize donor and graft selection may improve outcomes in the future.

Survival in patients with malignancy and venous thromboembolism by tumour subtype and thrombus location

BACKGROUND

Although the association between malignancy and venous thromboembolism (VTE) is firmly established, less is known about the survival following VTE among different malignant subtypes.

AIMS

We sought to estimate survival from first VTE in consecutive patients with known malignancy receiving extended low molecular weight heparin therapy.

METHODS

Five hundred and fifty-nine consecutive patients presenting to the Thrombosis Unit Registry at Auckland City Hospital between January 1997 and October 2006 were observed. Events were confirmed by standard imaging procedures. The diagnosis date and site of VTE as well as the type of malignancy were recorded.

RESULTS

Mean follow up was 21.4 months. Overall median survival from VTE was 13.5 months. Six-month, one-, two- and five-year survivals were 64%, 53%, 43% and 33% respectively. Survival was longest for haematological malignancy at 44.4 months, followed by prostate, bowel, breast (metastatic breast), lung and pancreatic malignancy at 29.4, 27.4, 15.5 (6.2), 2.4 and 1.9 months respectively. Median survival varied with thrombotic location from 31.1 months for upper limb/jugular deep vein thrombosis reducing to only 10.1 months for iliocaval/abdominal deep vein thrombosis, but this did not reach statistical significance. Survival from cancer diagnosis was also determined.

DISCUSSION

The 1-year 53% survival in cancer patients with VTE treated using extended low molecular weight heparin is longer than that reported from large registry and population studies in which specific patient information and therapeutic regimens are unknown. Survival is critically determined by tumour type and correlates with tumour stage in women with breast cancer. There is also a trend towards differing survival by thrombus location.