Outcomes in children with first-relapsed acute lymphoblastic leukemia in Japan: Results from JCCG Study JPLSG-ALL-R08.

BACKGROUND/OBJECTIVES: The Berlin-Frankfurt-Münster (BFM)-S classification is a crucial prognostic indicator in children experiencing first-relapsed acute lymphoblastic leukemia (ALL). Early molecular response to therapy, evaluated by measurable/minimal residual disease (MRD), has a significant impact on the survival of patients with childhood ALL. Applying risk stratification based on the BFM-S classification and MRD response after induction, the first nationwide prospective multicenter study, ALL-R08, was conducted in children with first-relapsed ALL in Japan. METHODS: The ALL-R08 study comprised two parts: ALL-R08-I, an observational study aimed at obtaining an overall picture of outcomes in first-relapsed childhood ALL, and ALL-R08-II, a clinical trial for the non-T-ALL S2 risk group. In ALL-R08-II, patients with an MRD level of ≥10-3 at the end of induction therapy were assigned to undergo allogeneic hematopoietic stem cell transplantation (allo-HCT), whereas those with an MRD level less than 10-3 and isolated extramedullary relapse continued to receive chemotherapy. RESULTS: In total, 163 patients were enrolled in the ALL-R08 study, and 82 and 81 patients were enrolled in the ALL-R08-I and the ALL-R08-II, respectively. In ALL-R08-I, the probability of 3-year event-free survival (EFS) for patients with S1, S2, S3, S4, and post-HCT groups was 83% ± 15%, 37% ± 11%, 28% ± 8%, 14% ± 7%, and 0%, respectively. In the ALL-R08-II trial, 3-year EFS in patients with post-induction MRD less than 10-3 and ≥10-3 was 70% ± 9% (n = 27) and 68% ± 8% (n = 31) (p = .591), respectively. CONCLUSIONS: ALL-REZ BFM-type treatment is equally effective for children with first-relapsed ALL treated according to the Japanese frontline protocols and for children with first-relapsed ALL treated according to the BFM-type frontline protocols.

Treatment of relapsed acute lymphoblastic leukemia in children: an observational study of the Japan Children's Cancer Group.

The Japan Children's Cancer Group Relapsed Acute Lymphoblastic Leukemia (ALL) Committee conducted a prospective observational study (ALL-R14) to explore promising reinduction therapy regimens for relapsed ALL to investigate in future trials. In Japan, clofarabine- and bortezomib-based regimens were of interest since they were newly introduced for ALL in the study period (2015-2018). Seventy-five pediatric patients were enrolled in total. The 2-year event-free/overall survival rates in patients with first (n = 59) or second (n = 11) relapse were 40.1% (95% confidence interval [CI]: 25.5-52.3%)/66.3% (95% CI 52.3-77.0%) and 34.1% (95% CI 9.1-61.6%)/62.3% (95% CI 27.7-84.0%), respectively. Clofarabine- or bortezomib-based regimens were used only in patients with high-risk disease. The first reinduction therapy used in the 41 patients with early or multiple relapsed B-cell precursor ALL was clofarabine in 7 patients and bortezomib in 9 patients. The odds ratio for reinduction failure risk with a clofarabine- or bortezomib-based regimen compared with other regimens was 9.0 (95% CI 0.9-86.4, P = 0.057) or 1.9 (95% CI 0.4-8.7, P = 0.42), respectively. Thus, clofarabine- or bortezomib-based regimens had no obvious advantage as reinduction therapy for relapsed ALL in children.

TBI, etoposide, and cyclophosphamide conditioning for intermediate-risk relapsed childhood acute lymphoblastic leukemia.

BACKGROUND: In children with intermediate-risk relapsed acute lymphoblastic leukemia (ALL), allogeneic hematopoietic stem cell transplantation (allo-HSCT) has markedly improved the outcome of patients with an unsatisfactory minimal residual disease (MRD) response. Total body irradiation (TBI), etoposide (ETP), and cyclophosphamide (CY) have been shown to be equivalent to or better than TBI + ETP for conditioning, so we hypothesized that even greater survival could be achieved due to recent advances in HSCT and supportive care. PROCEDURE: We prospectively analyzed the efficacy and safety of allo-HSCT with a unified conditioning regimen of TBI + ETP + CY in children with intermediate-risk relapsed ALL, based on MRD in the bone marrow after induction, from the Japanese Pediatric Leukemia/Lymphoma Study Group (JPLSG) ALL-R08-II nationwide cohort (UMIN000002025). RESULTS: Twenty patients with post-induction MRD ≥ 10-3 and two not evaluated for MRD underwent allo-HSCT. Engraftment was confirmed in all patients, and no transplantation-related mortality was observed. The 3-year event-free survival and overall survival rates after transplantation were 86.4% ± 7.3% and 95.5% ± 4.4%, respectively. CONCLUSION: Allo-HSCT based on post-induction MRD with TBI + ETP + CY conditioning was feasible in Japanese children with intermediate-risk relapsed ALL.

Eculizumab treatment in paediatric patients diagnosed with aHUS after haematopoietic stem cell transplantation: a HSCT-TMA case series from Japanese aHUS post-marketing surveillance.

Haematopoietic stem-cell transplantation (HSCT)-associated thrombotic microangiopathy (HSCT-TMA) is a serious complication with high mortality. Accumulating evidence suggests that complement dysregulation is potentially involved in the development of HSCT-TMA. We retrospectively analysed the clinical characteristics and outcomes of thirteen paediatric patients who were diagnosed with atypical haemolytic uremic syndrome and treated with eculizumab to manage HSCT-TMA during post-marketing surveillance in Japan. The median time from HSCT to TMA was 31 days (Interquartile range, IQR;21-58) and the median doses of eculizumab was three (IQR;2-5). Seven patients (54%) were alive at the last follow-up while six died due to complications related to HSCT. Six of seven survivors initiated eculizumab after insufficient response to plasma therapy. Following eculizumab treatment, median platelet counts and LDH levels in all survivors significantly improved and renal function improved in 4/7 patients. All survivors possessed potential risk factors of complement overactivation. During the follow-up period after eculizumab discontinuation (median;111.5 days, IQR;95-555), no TMA recurrence was observed. In this analysis, eculizumab showed benefit in over half of this paediatric patient population. Ongoing clinical studies are expected to optimize the treatment regimen of terminal complement pathway inhibitor, and it may become a therapeutic option for paediatric HSCT-TMA in the future.

The Novel Gabapentinoid Mirogabalin Prevents Upregulation of α2δ-1 Subunit of Voltage-Gated Calcium Channels in Spinal Dorsal Horn in a Rat Model of Spinal Nerve Ligation.

Gabapentinoids are specific ligands for the α2δ-1 subunit of voltage-gated calcium channels. This class of drugs, including gabapentin and pregabalin, exert various pharmacological effects and are widely used for the treatment of epilepsy, anxiety, and chronic pain. The mechanism of action of gabapentinoids involves both direct modulation of calcium channel kinetics and inhibition of channel trafficking and expression, which contribute to the above pharmacological effects. In the present study, we investigated the effects of mirogabalin, a novel potent gabapentinoid, on expression levels of the α2δ-1 subunit in the spinal dorsal horn in a rat model of spinal nerve ligation (SNL) as an experimental animal model for peripheral neuropathic pain. The neuropathic pain state was induced by SNL in male Sprague - Dawley rats. After the development of mechanical hypersensitivity, the animals received 10 mg/kg mirogabalin or vehicle orally for 5 consecutive days and were subjected to immunohistochemical analysis of α2δ-1 subunit expression in the spinal cord. In the SNL model rats, expression of the α2δ-1 subunit significantly increased in the spinal dorsal horn at the ipsilateral side of nerve injury, while mirogabalin inhibited this increase. In conclusion, the α2δ-1 subunit was upregulated in the spinal dorsal horn of SNL model rats, and repeated administration of mirogabalin inhibited this upregulation. The inhibitory effect of mirogabalin on upregulation of the α2δ-1 subunit after nerve injury is considered to contribute to its analgesic effects in peripheral neuropathic pain.

The impact of vitamin D on the onset and progress of Kawasaki disease.

BACKGROUND: The seasonal epidemic of Kawasaki disease (KD) in winter in Japan suggests that low vitamin D status may affect KD through the immune system. We aimed to evaluate the effect of vitamin D on the onset and clinical course of KD. METHODS: We conducted a case-control study to compare 25-hydroxyvitamin D (25(OH)D) levels in KD patients admitted to our hospital between March 2018 and June 2021, with those in healthy controls from published Japanese data. In patients with KD, we evaluated the association of 25(OH)D levels with intravenous immunoglobulin resistance and coronary artery lesions. RESULTS: We compared 290 controls and 86 age-group-adjusted patients with KD. The 25(OH)D levels in KD patients were lower than those in the controls (median: 17 vs. 29 ng/mL, P < 0.001). In winter, 25(OH)D levels in KD patients were lower than those in summer (median: 13 vs. 19 ng/mL). The adjusted odds ratios for the onset of KD were 4.9 (95% CI: 2.5-9.6) for vitamin D insufficiency (25(OH)D: 12-20 ng/mL) and 29.4 (95% CI: 12.5-78.2) for vitamin D deficiency (25(OH)D < 12 ng/mL). Among 110 KD patients, 25(OH)D levels at diagnosis of KD were not associated with intravenous immunoglobulin resistance or coronary artery lesions. CONCLUSIONS: The 25(OH)D levels in patients with KD were lower than those in the controls, especially in winter. Lower 25(OH)D levels in winter were associated with an increased risk of KD onset. It remains to be elucidated whether the observed association has a causal relationship.

Reversible Cerebral Vasoconstriction Syndrome Promptly Diagnosed with Magnetic Resonance Imaging Including Magnetic Resonance Angiography During Immunosuppressive Therapy in a 16-Year-Old Girl with Refractory Cytopenia of Childhood.

Reversible cerebral vasoconstriction syndrome (RCVS) is a syndrome characterized by severe headache with segmental vasoconstriction of the cerebral arteries that resolves within 12 weeks. A 16-year-old girl with refractory cytopenia of childhood, who was receiving the immunosuppressant cyclosporine, developed severe headache and was diagnosed with RCVS using magnetic resonance imaging, including magnetic resonance angiography (MRA). MRA is a non-invasive and very effective technique for diagnosing RCVS. MRA should be performed at the onset of severe headache during immunosuppressant administration for children with hematological disorders and may prevent sequelae such as posterior reversible encephalopathy syndrome or ischemic attack.

Evans syndrome after unrelated bone marrow transplantation for refractory cytopenia of childhood.

Post-transplant ES, which is often resistant to therapies, has seldom been described. This report describes a case of ES after UBMT for RCC. A five-yr-old boy developed RCC with no evidence of monosomy 7. Because no matching family donors were available for SCT and immunosuppressive therapy was ineffective, UBMT was performed when he was six yr old. The conditioning regimen included TAI (3 Gy) and administration of FLU, CY, and rabbit antithymocyte globulin. The recovery of blood cells was good. He displayed grade II acute GVHD involving only the skin. ES developed on day 66, with positive results for Epstein-Barr virus DNA and HHV 6. Cytopenia was resolved with treatment with RTX, GCV, an escalated dose of steroids, high-dose gammaglobulin, and romiplostim. No relapse has occurred since discontinuing steroids on day 177 and romiplostim on day 268. Post-SCT ES after UBMT is rare, and the risk factors and therapies are unclear. Prospective analysis and collection of cases from multiple centers are required for clarification.

A case of NUT midline carcinoma with complete response to gemcitabine following cisplatin and docetaxel.

BACKGROUND: NUT midline carcinoma (NMC) is recognized as a very rare tumor that most often occurs around the midline and shows NUT rearrangement. This tumor affects children and younger adults, progresses rapidly, and shows an extremely poor prognosis, even with intensive chemotherapy. Very few reports have described effective treatment for this tumor. METHODS: A 12-year-old girl with NMC was treated using cisplatin (CDDP), docetaxel, gemcitabine, pemetrexed, and vinorelbine. RESULTS: Imaging showed partial response with CDDP and docetaxel, and complete response with gemcitabine. After reexacerbation of the tumor, although partial response was achieved with vinorelbine, the patient died 89 weeks after onset because of reexacerbation. CONCLUSIONS: NMC is a very rare disease with poor prognosis. This study is the first to report response of NMC to gemcitabine and vinorelbine. The findings suggest that combination chemotherapies including CDDP, docetaxel, gemcitabine, and vinorelbine may be a choice in the treatment for NMC.

Osteosarcoma after bone marrow transplantation.

Three children treated with bone marrow transplantation for acute lymphoblastic leukemia, Diamond-Blackfan anemia, and congenital amegakaryocytic thrombocytopenia developed secondary osteosarcoma in the left tibia at the age of 13, 13, and 9 years, respectively, at 51, 117, and 106 months after transplantation, respectively. Through treatment with chemotherapy and surgery, all 3 patients are alive without disease. We surveyed the literature and reviewed 10 cases of osteosarcoma after hematopoietic stem cell transplantation (SCT), including our 3 cases. Eight of the patients had received myeloablative total body irradiation before SCT. The mean interval from SCT to the onset of osteosarcoma was 6 years and 4 months, and the mean age at the onset of osteosarcoma was 14 years and 5 months. The primary site of the post-SCT osteosarcoma was the tibia in 6 of 10 cases, in contrast to de novo osteosarcoma, in which the most common site is the femur. At least 7 of the 10 patients are alive without disease. Osteosarcoma should be one of the items for surveillance in the follow-up of patients who undergo SCT.

Pathology of canine oral malignant melanoma with cartilage and/or osteoid formation.

Of 197 cases of canine oral malignant melanoma, 29 cases with myxoid, cartilage, and osteoid formation were studied pathologically and immunohistochemically. Tumor tissues were classified into spindle cell type (13 cases), epithelioid cell type (1 case), and mixed type (15 cases). Myxoid matrixes (29 tumors) were formed mainly in the tissues of spindle cell type and were positive for Alcian blue (pH 2.5). Cartilaginous matrixes (12 tumors) were formed in the myxoid tumor tissues. The morphology of atrophied neoplastic cells, which were embedded in the cartilage cavities, significantly differed from that of spindle cells proliferating in surroundings. There were reticular areas in the process of transitioning from myxoid to cartilaginous matrixes. Osteoid matrixes were not continuous with myxoid or cartilaginous matrixes, and arose as eosinophilic trabeculae in the dense collagenous connective tissues. A calcified bone trabecula was present among the osteoid trabeculae in a case. Melanin-producing melanocytes were proliferating in the collagenous matrixes, while amelanotic cells were in the osteoid matrixes. Immunohistochemistry demonstrated proliferating neoplastic cells as melanocytes. All cells in/out of these three matrixes were positive for Melan-A, S-100 protein, NSE, and vimentin. From these results, it is suggested that cartilage and osteoid matrixes are produced by dedifferentiated melanocytes.

Pneumonia in horses induced by intrapulmonary inoculation of Streptococcus equi subsp. zooepidemicus.

To evaluate the possibility that Streptococcus equi subsp. zooepidemicus (S.z) the causative bacterial agent of equine shipping fever pneumonia (ESFP), as well as to investigate its pathogenesis, 10 horses (seven Thoroughbreds and three Anglo-Arab species, ranging from 2-4 years in age) were experimentally inoculated, via an endoscope, into bronchus of the lung lobe with a dose of 30 ml of 1-7 x 10(8) CFU/ml of S.z. After inoculation, autopsy and pathological examinations were sequentially conducted 30 min, 1, 2, 3, 4, 17, 20 hr and 2 weeks later. Pneumonia induced by the intrapulmonary inoculation of S.z was characterized by small purulent pneumonic foci in the inoculated areas. With the lapse of time, these foci developed into serous hemorrhagic pneumonia, hemorrhagic purulent pneumonia, and then purulent, coagulation necrotic pneumonia. These pathomorphological characteristics of experimental pneumonia closely resemble those naturally occurring ESFP. There is strong evidence that S.z. is implicated as a causal factor in ESFP. S.z. grew in the mucus, exudate, and pulmonary effusions. Further, the bacteria showed resistance against phagocytosis by pulmonary alveolar macrophages (PAM) and neutrophils. Inhibition of PAM and neutrophil function is considered to be important in the development of pneumonia. With the progression of the disease, the neutrophils often adhered to the endothelial surface of the alveolar capillary lumen and played a role in generating coagulation necrosis of lung tissues.

Prophylaxis and treatment of influenza encephalitis in an experimental mouse model.

A mouse model study using mouse brain-adapted influenza A virus was performed to establish the prophylaxis and treatment of influenza encephalitis and encephalopathy. All mice died after intranasal inoculation of the brain-adapted influenza A virus (H7N3), and the pathological findings indicated the presence of significant encephalitis. Viral antigen was also detected in the brain, both pathologically and virologically. By contrast, infected mice immunized with inactivated vaccine of the same strain did not lose weight, which is an indicator of the overall condition of the mice, and all of them survived. Similarly, antiserum treatment in the early period (0-1 day post-infection) resulted in 100% survival, and no pathological findings were observed in the brain. However, mice treated with antiserum 3 days post-infection showed encephalitis with viral antigens in both glial cells and neurocytes. Although amantadine treatment for 4 days delayed weight loss, it did not prevent death from encephalitis. These results show vaccination and early antiserum treatment to be highly effective, whereas 4-day treatment of amantadine was not very effective in treating or preventing influenza encephalitis. The life-prolonging effect of amantadine, however, suggests that use of amantadine together with other treatments may inhibit the progression of encephalitis.