Identification of the novel HLA-B*58:138 allele in a Korean individual.

HLA-B*58:138 differs from HLA-B*58:01:01:01 by one nucleotide substitution in exon 3 at codon 145.

Relative immunogenicity of blood group antigens: First report in a Korean population.

BACKGROUND: The immunogenicity of a blood group antigen is a measure of its likelihood of inducing alloantibodies. Although the immunogenicity of blood group antigens has been analyzed in Caucasian populations, immunogenicity to date has not been analyzed in Asian subjects. The present study therefore evaluated the relative immunogenicity of blood group antigens in a Korean population. STUDY DESIGN AND METHODS: All available data of unexpected antibody identification tests performed at Asan Medical Center between 1997 and 2021 were analyzed. The relative immunogenicity of a blood group antigen relative to K antigen was calculated based on relative numbers of alloantibodies and the probabilities of antigen-negative recipients receiving antigen-positive RBC units. RESULTS: A total of 3898 antibody identification results were included, with 1632 (41.9 %) from male patients. The ranking of antigen immunogenicity was: E > c > e > C > K > Jk(a) > Lu(a) > S > Fy(a) > Fy(b) > Jk(b) > Di(b) > Di(a) in the total population and E > c > e > C > Jk(a) > Fy(a) > Fy(b) > S > K > Lu(a) > Jk(b) > Di(b) > Di(a) in male patients. DISCUSSION: The rank order of immunogenicity for blood group antigens in this study provides information about relative immunogenecity in Koreans. These findings also provide supporting evidence regarding antigen selection for extended antigen-matched transfusions in recipients of multiple transfusions.

A New Trial to Measure ABO Antibodies Using Complement-Dependent Cytotoxicity.

Background and objectives: The ABO antibody (Ab) titration tests are used in monitoring in ABO-incompatible (ABOi) solid organ transplantation (SOT). However, currently developed ABO Ab tests show Ab binding reactions. This study attempted to measure ABO Ab level using complement-dependent cytotoxicity (CDC). Materials and methods: We studied 93 blood group O serum samples from patients who underwent ABOi SOT from January 2019 to May 2021. Patients' sera were incubated with A1 or B cells and added to a human complement solution. Supernatants were collected after centrifugation, and free hemoglobin (Hb) was measured by spectrophotometry. We converted plasma Hb value to hemolysis (%), which were compared with ABO Ab titer. Results: We found a mild correlation between hemolysis and ABO Ab titers. In simple regression analysis, the correlation coefficients were within 0.3660−0.4968 (p < 0.0001) before transplantation. In multiple linear regression analysis, anti-A hemolysis (%) was higher in immunoglobulin M (IgM) (ß = 12.9) than in immunoglobulin G (IgG) (ß = −3.4) (R2 = 0.5216). Anti-B hemolysis was higher in IgM (ß = 8.7) than in IgG (ß = 0.0) (R2 = 0.5114). There was a large variation in hemolysis within the same Ab titer. Conclusions: CDC can be used in a new trial for ABO Ab measurement. Furthermore, IgM rather than IgG seems to play a significant role in vivo activity, consistent with previous knowledge. Thus, this study may help in the development of the ABO Ab titration supplement test for post-transplant treatment policy establishment and pre-transplant desensitization.

Evaluation and management of platelet transfusion refractoriness.

Platelet transfusion refractoriness (PTR), in which platelet counts do not increase after transfusion, occurs in many patients receiving platelet transfusions. PTR is a clinical condition that can harm patients. The causes of PTR can be divided into two types: immune and non-immune. Most cases of PTR are non-immune. Among immune causes, the most common is human leukocyte antigen (HLA) class I molecules. PTR caused by anti-HLA antibodies is usually managed by transfusing HLA-matched platelets. Therefore, it is important, especially for hemato-oncologists who frequently perform transfusion, to accurately diagnose whether the cause of platelet transfusion failure is alloimmune or non-immunological when determining the treatment direction for the patient. In this review, we discuss the definitions, causes, countermeasures, and prevention methods of PTR.

Detection of anti-B antibodies in a patient with A1B blood group: A case report and literature review.

ABO antibodies occur naturally and usually exist as alloantibodies. They are the most clinically significant in cases of transfusions. However, there are very few reports on auto-anti-A or B. A 58-year-old man visited our hospital for evaluation of an inguinal mass. Blood typing was performed, while preparing the patient for an excisional biopsy. Forward and reverse typing showed a typical AB and A pattern. Results of the direct antiglobulin and unexpected antibody screening tests were negative. The serum did not react with AB3 cells. The biopsy revealed a diffuse large B-cell lymphoma. After completing four cycles of R-CHOP chemotherapy, the patient achieved complete remission. There were no anti-B antibodies found on repeat ABO typing. This report shares our experience on unexpected anti-B antibody findings in a patient with an A1B blood type. To the best of our knowledge, this is the first report of anti-B antibodies in a patient with an A1B blood type in Korea.

Comparison of clinical and laboratory characteristics of nonsecretory multiple myeloma and secretory multiple myeloma in a tertiary care hospital.

INTRODUCTION: Nonsecretory multiple myeloma (NSM) is a rare variant of multiple myeloma, accounting for approximately 1%-5% of all reported cases. We compared the characteristics of NSM and secretory multiple myeloma (SM). METHODS: We examined clinical and laboratory characteristics of 17 patients diagnosed with NSM and 40 patients diagnosed with SM. NSM was diagnosed based on findings of bone marrow (BM) examination, serum-free light chain (sFLC) assay, flow cytometric (FCM) immunophenotyping, chromosomal analysis, and imaging studies. RESULTS: No patient with NSM had hypercalcemia or renal insufficiency at diagnosis. Patients with NSM were less anemic (p < .05) but had higher lactate dehydrogenase levels (p < .05) than patients with SM. In addition, patients with NSM had a lower percentage of plasma cells in the BM, confirmed by manual differential count (p < .05) and FCM immunophenotyping (p < .05). The sFLC ratio in patients with NSM was abnormal (15/17, 88.2%) and was lower than that in patients with SM (p < .05). Risk stratification in Revised International Staging System revealed a low-risk tendency in patients with NSM (p = .235). CONCLUSION: NSM patients showed different clinical and laboratory characteristics from SM patients. FCM immunophenotyping and sFLC assay particularly had differences between NSM patients and SM patients. Thus, they are essential for diagnosing NSM.

Valproic acid protects intestinal organoids against radiation via NOTCH signaling.

Radiotherapy is a leading treatment for various types of cancer. However, exposure to high-dose ionizing radiation causes acute gastrointestinal injury and gastrointestinal syndrome. This has significant implications for human health, and therefore, radioprotection is a major area of research. Radiation induces the loss of intestinal stem cells; hence, the protection of stem cells expressing LGR5 (a marker of intestinal epithelial stem cells) is a key strategy for the prevention of radiation-induced injury. In this study, we identified valproic acid (VPA) as a potent radioprotector using an intestinal organoid culture system. VPA treatment increased the number of LGR5+ stem cells and organoid regeneration after irradiation. N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester (DAPT, an inhibitor of NOTCH signaling) blocked the radioprotective effects of VPA, indicating that NOTCH signaling is a likely mechanism underlying the observed effects of VPA. In addition, VPA acted as a radiosensitizer via the inhibition of histone deacetylase (HDAC) in a colorectal cancer organoid. These results demonstrate that VPA exerts strong protective effects on LGR5+ stem cells via NOTCH signaling and that the inhibition of NOTCH signaling reduces these protective effects, providing a basis for the improved management of radiation injury.

Gonadotropin regulates NUCB2/nesfatin-1 expression in the mouse ovary and uterus.

NUCB2/nesfatin-1 is expressed in the hypothalamus and regulates food intake and energy metabolism. Recent studies showed that NUCB2/nesfatin-1 also plays a role in other organs. However, its expression pattern and function in female reproductive organs are unclear. Therefore, we investigated NUCB2/nesfatin-1 expression in the ovary and uterus of mice and determined whether it is regulated by gonadotropins and sex steroid hormones. NUCB2 mRNA and nesfatin-1 protein were detected in the ovary and uterus of mice. NUCB2/nesfatin-1 expression in both organs was highest in the estrus period of the estrus cycle. Administration of pregnant mare serum gonadotropin (PMSG) dose-dependently increased mRNA expression of NUCB2 in the ovary and uterus of mice. On the other hand, mRNA expression of NUCB2 in the uterus was dramatically decreased after ovariectomy and was not increased upon administration of PMSG. Injection of 17ß-estradiol upregulated mRNA expression of NUCB2 in the uterus of ovariectomized mice, whereas injection of progesterone did not. These results suggest that NUCB2/nesfatin-1 expression in the ovary and uterus of mice is regulated through the hypothalamus-pituitary-ovary axis and that NUCB2/nesfatin-1 is a local regulator of ovarian steroidogenesis and uterine function.

5-(4-chlorophenyl)-1-(4-methoxyphenyl)-3-trifluoromethylpyrazole acts in a reactive oxygen species-dependent manner to suppress human lung cancer growth.

PURPOSE: 5-(4-chlorophenyl)-1-(4-methoxyphenyl)-3-trifluoromethylpyrazole (SC-560) is a structural analog of celecoxib. Recent studies suggested that SC-560 inhibits the in vivo proliferation of colon and breast cancer cells to an extent similar to that observed in celecoxib, and that SC-560 exerts their growth inhibitory effects in a cyclooxygenase-independent manner. METHODS: In the current study, we sought to investigate the mechanism by which SC-560 inhibits the growth of human lung cancer cells. RESULTS: SC-560 more potently inhibited the growth of human A549, H460, and H358 lung cancer cell lines compared with that of human BEAS-2B normal bronchial epithelial cells. SC-560-induced growth inhibition was mainly due to the induction of cell-cycle arrest at the G1 phase without apoptosis induction. SC-560 rapidly and dose-dependently induced the generation of reactive oxygen species (ROS), followed by accumulation of cells at the G1 phase. Antioxidant pretreatment blocked the cell-cycle arrest and growth inhibition induced by SC-560. Combination treatment with other ROS-inducing agents such as alpha-tocopheryl succinate (TOS) augmented cellular response against SC-560, leading to synergistic apoptosis induction and growth suppression. Our data also showed that the apoptosis induced by combination treatment with SC-560 and TOS was mediated through ROS-dependent caspase activation. CONCLUSION: Collectively, our results demonstrate that SC-560 acts in a ROS-dependent manner to induce growth suppression in human lung cancer cells.

Enhanced anticancer efficacy of alpha-tocopheryl succinate by conjugation with polyethylene glycol.

Alpha-tocopheryl polyethylene glycol succinate (TPGS) has been used to enhance the bioavailability of poorly absorbed drugs and as a vehicle for drug delivery systems. In response to recent reports that alpha-tocopheryl succinate (TOS) acts as an anticancer agent, we investigated whether its polyethylene glycol (PEG) conjugate, TPGS, also possesses anticancer activity. TPGS inhibited the growth of human lung carcinoma cells implanted in nude mice, and in an in vitro cell culture, even more potently than TOS. The time-dependent uptake of TPGS into cells did not differ from that of TOS, indicating that the enhanced antitumor efficacy of TPGS was not due to its increased uptake into cells. Compared with TOS, TPGS was more effective at inducing apoptosis and the generation of reactive oxygen species, suggesting that the superior anticancer efficacy of TPGS is associated with its increased ability to induce apoptosis. Our data suggest that further studies assessing the potential usefulness of TPGS in cancer therapeutics are warranted, since its use as a vehicle in the formulation of anticancer drugs may provide an effective way to improve their therapeutic efficacy.

Potentiation by alpha-tocopheryl succinate of the etoposide response in multidrug resistance protein 1-expressing glioblastoma cells.

Multidrug resistance protein 1 (MRP1) is one of the representative members of the ATP-binding cassette superfamily of transporters that is involved in resistance to chemotherapeutic agents in cancer patients. MRP1 functions as an efflux pump of drugs, primarily those conjugated to glutathione (GSH). Decreases in the intracellular concentration of GSH have been shown to enhance the response of MRP1-overexpressing cells to MRP1-substrate drugs by limiting the available drug-GSH conjugates. We report here that alpha-tocopheryl succinate (TOS), a vitamin E analogue, decreased intracellular GSH concentration and blocked MRP1 function in glioblastoma cells. Functional blockade by TOS of MRP1 was confirmed by the enhanced accumulation of etoposide (VP-16), an MRP1-substrate drug. As a result, co-treatment of TOS with VP-16 or treatment with liposomes containing both TOS and VP-16 greatly enhanced the response of MRP1-expressing glioblastoma cells to VP-16. TOS may be a promising adjuvant for enhancing the therapeutic efficacy of VP-16 in patients with MRP1-expressing glioblastomas.