Haploidentical donor stem cell transplantation had a lower incidence of bronchiolitis obliterans syndrome compared with HLA-matched sibling donor transplantation in patients with hematologic malignancies: Benefit from ATG?

Background: Haploidentical donor stem cell transplantation (HID-SCT) based on antithymocyte globulin (ATG) for graft-versus-host disease (GVHD) prophylaxis had achieved a similar incidence of chronic graft-versus-host disease (cGVHD) with human leukocyte antigen (HLA)-matched sibling donor stem cell transplantation (MSD-SCT). However, bronchiolitis obliterans syndrome (BOS), which serves as pulmonary cGVHD, was rarely compared between HID and MSD transplantation. Methods: One thousand four hundred five patients with hematologic malignancies who underwent allogeneic SCT were enrolled in this retrospective study. Based on donor type, we divided the patients into three groups: HID, MSD, and match unrelated donor (MUD) groups. The cumulative incidences and risk factors of BOS were analyzed. Results: The 5-year cumulative incidence of BOS was 7.2% in the whole population. HID transplantation had a lower 5-year cumulative incidence of BOS than MSD transplantation (4.1% vs. 10.0%, p < 0.001) and a similar incidence with MUD transplantation (4.1% vs. 6.2%, p = 0.224). The 5-year cumulative incidence of BOS was lower in the ATG group than that in the non-ATG group in both the whole and MSD populations (4.6% vs. 11.2%, p < 0.001, and 4.1% vs. 11.2%, p = 0.042, respectively). The 5-year incidence of BOS in mixed grafts [peripheral blood stem cell (PBSC) plus bone marrow] group was also lower than that in the PBSC group (4.2% vs. 9.1, p = 0.001). Multivariate analysis showed that HID, ATG, and mixed grafts were protective factors for BOS [odds ratio (OR) 0.3, 95% CI 0.2-0.6, p < 0.001; OR 0.3, 95% CI 0.2-0.7, p = 0.001; OR 0.3, 95% CI 0.1-0.8, p = 0.013], and acute graft-versus-host disease (aGVHD) and cGVHD were independent risk factors for BOS (OR 2.1, 95% 1.1-4.3, p = 0.035; OR 10.1, 95% CI 4.0-25.0, p < 0.001). Conclusions: HID transplantation had a lower incidence of BOS than MSD transplantation, which might be associated with ATG and mixed grafts.

Rabbit Hemorrhagic Disease Virus Isolated from Diseased Alpine Musk Deer (Moschussifanicus).

Rabbit hemorrhagic disease virus (RHDV) is the causative agent of rabbit hemorrhagic disease (RHD), and its infection results in mortality of 70-90% in farmed and wild rabbits. RHDV is thought to replicate strictly in rabbits. However, there are also reports showing that gene segments from the RHDV genome or antibodies against RHDV have been detected in other animals. Here, we report the detection and isolation of a RHDV from diseased Alpine musk deer (Moschussifanicus). The clinical manifestations in those deer were sudden death without clinical signs and hemorrhage in the internal organs. To identify the potential causative agents of the disease, we used sequence independent single primer amplification (SISPA) to detect gene segments from viruses in the tissue samples collected from the dead deer. From the obtained sequences, we identified some gene fragments showing very high nucleotide sequence similarity with RHDV genome. Furthermore, we identified caliciviral particles using an electron microscope in the samples. The new virus was designated as RHDV GS/YZ. We then designed primers based on the genome sequence of an RHDV strain CD/China to amplify and sequence the whole genome of the virus. The genome of the virus was determined to be 7437 nucleotides in length, sharing the highest genome sequence identity of 98.7% with a Chinese rabbit strain HB. The virus was assigned to the G2 genotype of RHDVs according to the phylogenetic analyses based on both the full-length genome and VP60 gene sequences. Animal experiments showed that GS/YZ infection in rabbits resulted in the macroscopic and microscopic lesions similar to that caused by the other RHDVs. This is the first report of RHDV isolated from Alpine musk deer, and our findings extended the epidemiology and host range of RHDV.