Alantolactone ameliorates graft versus host disease in mice

The anti-inflammatory and immunosuppressive drugs which are used in the treatment of Graft-versus-Host Disease (GVHD) have limited effects in controlling the severity of the disease. In this study, we aimed to investigate the prophylactic effect of Alantolactone (ALT) in a murine model of experimental GVHD. The study included 4 BALB/c groups as hosts: Naïve (n = 7), Control GVHD (n = 16), ALT-GVHD (n = 16), and Syngeneic transplantation (n = 10). Busulfan (20 mg/kg/day) for 4 days followed by cyclophosphamide (100 mg/kg/day) were administered for conditioning. Allogeneic transplantation was performed with cells collected from mismatched female C57BL/6, and GVHD development was monitored by histological and flow cytometric assays. Additionally, liver biopsies were taken from GVHD patient volunteers between ages 2-18 (n = 4) and non-GVHD patients between ages 2-50 (n = 5) and cultured ex vivo with ALT, and the supernatants were used for ELISA. ALT significantly ameliorated histopathological scores of the GVHD and improved GVHD clinical scores. CD8+ T cells were shown to be reduced after ALT treatment. More importantly, ALT treatment skewed T cells to a more naïve phenotype (CD62L+ CD44-). ALT did not alter Treg cell number or frequency. ALT treatment appears to suppress myeloid cell lineage (CD11c+). Consistent with reduced myeloid lineage, liver and small intestine levels of GM-CSF were reduced in ALT-treated mice. IL-6 gene expression was significantly reduced in the intestinal tissue. Ex vivo ALT-treated liver biopsy samples from GVHD patients showed a trend of decrease in pro-inflammatory cytokines but there was no statistical significance. Collectively, the data indicated that ALT may have immunomodulatory actions in a preclinical murine GVHD model.

Screening Chest CT Prior to Allogenic Hematopoietic Stem Cell Transplantation

Pulmonary complications constitute a major cause of morbidity and mortality in the post-allogenic hematopoietic stem cell transplantation (alloHSCT) period. Although chest X-ray (CXR) is customarily used for screening, we have used chest computed tomography (CT) scans. To characterize the prevalence of abnormalities and explore their impact on alloHSCT eligibility and outcomes post-transplantation, we conducted a retrospective analysis using real-world data collected at our center for adult patients who were evaluated for alloHSCT between January 2013 and December 2020 and identified 511 eligible patients. The most common primary disease was acute myeloid leukemia, in 49% of patients, followed by myelodysplastic syndrome (23%), lymphoma (11%), and acute lymphocytic leukemia (10%). Abnormal screening chest CT results were found in 199 patients (39%). The most frequent detected abnormality was pulmonary nodule, in 78 patients (35%), followed by consolidation in 42 (19%), ground-glass opacification in 33 (15%), bronchitis and bronchiolitis in 25 (11%), pleural effusions in 14 (6%), and new primary cancer in 7 (2%). CXR detected abnormalities in only approximately one-half of the patients (48%) with an abnormal chest CT scan. Among the 199 patients with an abnormal chest CT scan, 98 (49%) underwent further assessment and/or intervention before transplantation. The most common workup was pulmonary consultation in 32%, followed by infectious diseases consultation in 24%. Lung biopsy was obtained in 20%, and antimicrobial therapy was initiated after confirming an infection diagnosis in 20%. Patients with an abnormal chest CT scan demonstrated worse overall survival (P = .032), nonrelapse mortality (P = .015), and pulmonary-related mortality (P < .001) compared to those with a normal chest CT scan. Our study suggests that pretransplantation screening chest CT is beneficial in uncovering invasive infections and underlying malignancies and allows for appropriate interventions before alloHSCT to prevent potentially serious post-transplantation complications without causing a delay in alloHSCT. Nevertheless, abnormal CT findings prior to transplantation may be associated with overall worse prognosis.

Plasma cell leukemia - one in a million: A case report

BACKGROUND

Plasma cell leukemia (PCL) is diagnosed by the presence of an absolute plasma cell count of > 2 × 10⁹/L or 20% plasma cells in the peripheral blood. Because the incidence of PCL is relatively low, our case report study presents a rare opportunity to describe the clinical and pathological characteristics of this leukemia, as well as different modalities of treatment and outcomes of primary PCL (pPCL).

CASE SUMMARY

A 56-year-old male with a history of hypertension complained of pain in the left flank area which started four months prior to admission. On admission, his vital signs were stable, and physical examination was completely benign. Laboratory evaluation showed hemoglobin of 5.1 g/dL, white blood cell count of 6.6 cells per cubic millimeter with 16% atypical lymphocytes, and platelet count of 51000 per microliter. Peripheral smear showed more than 10%-15% of plasma cells (Figure 1), and flow cytometry of peripheral blood confirmed PCL with 24% plasma cells CD138+. Bone marrow biopsy demonstrated 80% plasma cells (38+, 138+, 117+, 10-, 19-, 20-, 56-) with 90% cellularity. The Oncology team was consulted, and VCD therapy was started. After completing therapy at 1, 4, 8, and 11 d, the patient was discharged home. The patient was being considered for a bone marrow transplant evaluation within two months of discharge.

CONCLUSION

PCL is a rare and aggressive form of leukemia with a poor prognosis. Multi-center studies and clinical trials should be conducted to develop accurate criteria for the initial diagnosis and prompt treatment of this disease.

Host-Derived Serine Protease Inhibitor 6 Provides Granzyme B-Independent Protection of Intestinal Epithelial Cells in Murine Graft-versus-Host Disease

Graft-versus-host disease (GVHD) is a serious complication after allogeneic hematopoietic cell transplantation (allo-HCT) that limits the therapeutic potential of this treatment. Host antigen-presenting cells (APCs) play a vital role in activating donor T cells that subsequently use granzyme B (GzmB) and other cytotoxic molecules to damage host normal tissues. Serine protease inhibitor 6 (Spi6), known as the sole endogenous inhibitor of GzmB, has been implicated in protecting T cells and APCs against GzmB-inflicted damage. In this study we used murine models to examine the previously unknown role of host-derived Spi6 in GVHD pathogenesis. Our results indicated that host Spi6 deficiency exacerbated GVHD as evidenced by significantly increased lethality and clinical and histopathologic scores. Using bone marrow chimera system, we found that Spi6 in nonhematopoietic tissue played a dominant role in protecting against GVHD and was significantly upregulated in intestinal epithelial cells after allo-HCT, whereas Spi6 in hematopoietic APCs surprisingly suppressed alloreactive T cell response. Interestingly, the protective effect of Spi6 and its expression in intestinal epithelial cells appeared to be independent of donor-derived GzmB. We used in silico modeling to explore potential targets of Spi6. Interaction tested in silico demonstrated that Spi6 could inhibit caspase-3 and caspase-8 with the same functional loop that inhibits GzmB but was not capable of forming stable interaction with caspase-1 or granzyme A. Using an in vitro co-culture system, we further identified that donor T cell-derived IFN-γ was important for inducing Spi6 expression in an intestinal epithelial cell line. Altogether, our data indicate that host Spi6 plays a novel, GzmB-independent role in regulating alloreactive T cell response and protecting intestinal epithelial cells. Therefore, enhancing host-derived Spi6 function has the potential to reduce GVHD.

Clinical Trials of Muse Cells

Among many kinds of somatic stem cells, hematopoietic stem cells are the cells that have been successfully applied to treating leukemia patients as forms of bone marrow and cord blood transplantation. Mesenchymal stem cells, collectable from several sources including the bone marrow and adipose tissue, are also widely applied to clinical trials for their easy accessibility and low risks of tumorigenesis, while their outcomes were shown to be not clinically relevant in several target diseases. The most important issue for the stem cells is whether the cells are safe and effective for curing diseases. In this chapter, the outline of the clinical trial in Muse cells is discussed.

Secular trends of bloodstream infections during neutropenia in 15 181 haematopoietic stem cell transplants: 13-year results from a European multicentre surveillance study (ONKO-KISS)

OBJECTIVES

Antibacterial resistance is emerging in patients undergoing haematopoietic stem cell transplantation (HSCT), and most data on the epidemiology of bloodstream infections (BSI)-causing pathogens come from retrospective single-centre studies. This study sought to investigate trends in the epidemiology of BSI in HSCT patients from a prospective multicentre cohort.

METHODS

We investigated changes in the incidence of causative organisms of BSI during neutropenia among adult HSCT patients for 2002-2014. The data were collected from a prospective cohort for infection surveillance in 20 haematologic cancer centres in Germany, Austria and Switzerland (ONKO-KISS).

RESULTS

A total of 2388 of 15 181 HSCT patients with neutropenia (1471 allogeneic (61.6%) and 917 autologous (38.4%) HSCT) developed BSI (incidence 15.8% per year). The incidence of Gram-negative BSI increased over time both in patients after allogeneic HSCT (allo-HSCT) and autologous HSCT (auto-HSCT). BSI caused by Escherichia coli in allo-HSCT patients increased from 1.1% in 2002 to 3.8% in 2014 (3/279 vs. 31/810 patients, p <0.001), and the incidence of BSI caused by enterococci increased from 1.8% to 3.3% (5 vs. 27 patients, p <0.001). In contrast, the incidence of BSI due to coagulase-negative staphylococci decreased in allo-HSCT patients from 8.2% to 5.1%, (23 vs. 40 patients, p <0.001) and in auto-HSCT patients from 7.7% to 2.0% (13/167 vs. 30/540 patients; p = 0.028 for period 2002-2011). No significant trends were observed for the incidence of BSI due to methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci or extended-spectrum β-lactamase-producing Enterobacteriaceae. The BSI case fatality remained unchanged over the study period (total of 477 fatalities, 3.1%).

CONCLUSIONS

The incidence of Gram-negative BSI significantly increased over time in this vulnerable patient population, providing evidence for reevaluating empiric therapy for neutropenic fever in HSCT patients.

Clinical implication of allogenic implantation of adipogenic differentiated adipose-derived stem cells

We recently reported that autologous adipogenic differentiated adipose-derived stem cells (ASCs) can potentially be used as an effective and safe therapy for soft-tissue regeneration. In the present study, we investigated whether adipogenic differentiated ASCs can be used for allogenic applications to enlarge their therapeutic use. The allogenic immune response of adipogenic differentiated ASCs was investigated by flow cytometry and mixed lymphocyte culture. To determine whether adipogenic differentiated ASCs can form new adipose tissue without immune rejection, these cells were implanted subcutaneously into allo- or xenogenic recipient mice. In addition, the safety of the allogenic implantation of adipogenic differentiated ASCs was explored in a phase I clinical study. Adipogenic differentiated ASCs do not express major histocompatibility complex (MHC) class II molecules and costimulatory molecules, and the expression levels of MHC class I decreased after differentiation. In addition, these cells do not elicit an immune response against MHC-mismatched allogenic lymphocytes and formed new adipose tissue without immune rejection in the subcutaneous region of MHC-mismatched mice. Moreover, these cells did not induce clinically significant local and systemic immune responses or adverse events in the subcutaneous region of donor-independent healthy subjects. These results suggest that adipogenic differentiated ASCs can be used as a "universal donor" for soft-tissue engineering in MHC-mismatched recipients.

Airway transplantation

No definitive solution has been discovered for replacing long segments or the entire trachea in humans. Most of this challenge stems from the specific function and mechanics that are almost impossible to replicate except in the setting of an allotransplantation, which requires lifelong immunosuppressive medication. Recently, tissue engineering provided significant evidence concerning the next promising therapeutic alternative for tracheal replacement. Underlying mechanism and pathways of cell-surface interactions, cell migration, and differentiation are essential to understand the complexity of tracheal tissue regeneration. Tracheal replacement remains challenging but initial steps toward an ideal therapeutic concept have been made.