Optimized flow cytometric detection of transient receptor potential vanilloid-1 (TRPV1) in human hematological malignancies.

The ectopic overexpression of transient receptor potential vanilloid-1 (TRPV1) has been detected in numerous solid cancers, including breast, prostate, pancreatic, and tongue epithelium cancer. However, the expression of TRPV1 in hematological malignancies remains unknown. Here we show through in silico analysis that elevated TRPV1 mRNA expression occurs in a range of hematological malignancies and presents an optimized flow cytometry method to rapidly assess TRPV1 protein expression for both cell lines and primary patient samples. Three anti-TRPV1 antibodies were evaluated for intracellular TRPV1 detection using flow cytometry resulting in an optimized protocol for the evaluation of TRPV1 in hematological malignant cell lines and patients' peripheral blood mononuclear cells (PBMC). Overexpression of TRPV1 was observed in THP-1 (acute monocytic leukemia) and U266B1 (multiple myeloma, MM), but not U937 (histiocytic lymphoma) compared to healthy PBMC. TRPV1 was also detected in all 49 patients including B-cell non-Hodgkin's lymphoma (B-NHL), MM, and others and 20 healthy controls. TRPV1 expression was increased in 8% of patients (MM = 2, B-NHL = 2). In conclusion, we provide an optimized flow cytometry method for routine expression analysis of clinical samples and show that TRPV1 is increased in a subset of patients with hematological malignancies.

Meeting the COVID challenge: Optimizing vCD34+ in cryopreserved HPC samples for implementation of an external QA Program.

BACKGROUND: The COVID-19 pandemic has forced a fundamental change in the global procurement of allogeneic hematopoietic progenitor cells (HPCs) for transplantation. To better meet the emergent challenges of transporting cryopreserved allogeneic HPC during pandemics, there is an urgent need for External Quality Assurance (EQA) programs to evaluate reproducibility and harmonization of viable CD34+ cell (vCD34+) HPC enumeration, as the current EQA programs are unsuitable for analysis of vCD34+. The cost-effective distribution of HPC cryopreserved reference samples (CRSs) with acceptable reproducibility and specificity is key to the success of a vCD34+ EQA program. METHODS: Cryopreserved HPC samples (n = 11) were either stored on dry ice for 1 to 4 days or for 1 day followed by liquid nitrogen (LN) storage for 1 to 3 days to assess optimal conditions for vCD34+ EQA. Flow cytometric enumeration of vCD34+ HPCs was performed using a single platform assay combined with 7-AAD viability dye exclusion. The optimum transportation condition was validated in pilot and multicenter national studies (n = 12). RESULTS: A combination of 1 day on dry ice followed by LN storage stabilized viability compared with continuous storage on dry ice. This study demonstrates that dispatch of CRSs on dry ice to recipient centers across a distance of ≤4000 km within 26 h, followed by LN storage, resulted in reproducible intercenter vCD34+ enumeration. The estimated cost of safer and more convenient dry ice delivery is >20-fold lower than that of LN. CONCLUSION: This approach can form the basis for economically and scientifically acceptable distribution of CRSs for external vCD34+ EQA.

Outpatient autologous stem cell transplantation in Royal Hobart Hospital, Tasmania: a single-centre, retrospective review in the Australian setting.

BACKGROUND: Several international centres have published their experiences with outpatient autologous stem cell transplantation (ASCT) as treatment of haematological malignancies. AIM: In this single-centre retrospective review, we aim to examine the outcomes of outpatient autograft and review healthcare resource utilisation in the pre-cytopenic period. METHODS: Patients undergoing ASCT in Royal Hobart Hospital, Tasmania between 2008 and 2018 had their records reviewed and key outcomes data collected based on whether they received inpatient/outpatient ASCT. An outpatient ASCT was defined as conditioning as an outpatient; patients could then be managed with an elective admission during the cytopenic period or admission only when clinically indicated. RESULTS: Of 231 ASCT performed, 135 (58%) were as outpatients: 59 used carmustine-etoposide-cytarabine-melphalan conditioning for lymphoma (BEAM-ASCT) and 76 used high-dose melphalan for myeloma and amyloidosis (MEL-ASCT). Approximately one-third of patients undergoing outpatient ASCT were admitted electively during nadir period; the majority of patients required minimal interventions prior to this time. The most common causes for unplanned hospitalisation (which occurred in 71 (80%) of the 89 planned outpatient transplants) were febrile neutropenia (39%) and mucositis (35%). Age was the only risk factor identified to increase risk of requiring unplanned hospitalisation. Use of oral antibiotic prophylaxis reduced febrile neutropenia rates among melphalan outpatient ASCT. Outpatient ASCT led to significantly reduced inpatient bed-days and overall cost (approximately A$13 000-A$16 000) compared with inpatient autografts, with no significant differences in engraftment, rates of febrile neutropenia, intensive care admissions or mortality. CONCLUSION: Outpatient autografts may save healthcare resources without compromising patient outcomes.

Standardization and Accreditation in Haemopoietic Stem Cell Transplantation - an Asia Pacific Perspective.

Standardization and formal accreditation of practices related to hematopoietic stem cell transplantation (HSCT) and therapies using hematopoietic-derived cellular products aim to promote quality in clinical and laboratory practice and provide knowledge to all stakeholders of centers. This article refers to three aspects of these processes starting with the importance of accurate viable CD 34 enumeration in HSCT. A highly accurate method of enumeration and a robust EQAS program is required, especially during the current COVID-19 pandemic. The second section shares experiences with FACT-JACIE accreditation at the Singapore General Hospital demonstrating how accreditation is part of continuous improvement and not only a destination. This journey can be difficult in many HSCT centers of low- and middle-income countries (LMICs) because of the intensive and rigorous requirements of the internationally accredited models. Hence, in LMICs, a staged movement toward establishing such standards must be considered. This approach is presented in the third section of the article with data on the current situation in countries reporting to the APBMT registry.

Cryopreserved human haematopoietic stem cells retain engraftment potential after extended (5-14 years) cryostorage.

Harvesting of stem cells during the early phases of treatment with no immediate intention to perform a stem cell transplant is becoming an increasingly common practice. Such "insurance" harvests are often stored for many years before being needed for transplant in a subsequent relapse. The effect of long-term cryostorage (5-14 years) on the viability and functional capacity of haematopoietic stem cells (HSCs) was investigated in 40 bone marrow and peripheral blood harvests using standard in vitro methods, the colony forming unit-granulocyte/macrophage (CFU-GM) assay and a single platform viable CD34(+) cell absolute count by flow cytometry. Forty percent of harvests had CD34(+) HSC counts of at least 0.7 x 10(6)/kg bodyweight and 85% had CFU-GM counts of at least 1.0 x 10(5)/kg bodyweight, these values representing our institutional minimum requirements for safe transplantation. Based on these results, it appears that HSC collections can remain adequate for safe transplantation after up to 14 years of cryostorage. However, as deterioration of HSC quality and viability may occur, some precautions may be warranted, namely harvesting higher than normal numbers of HSCs in collections intended for long-term storage and repeating in vitro assays on harvests after long-term storage prior to transplantation.