Immunogenicity and safety of heterologous versus homologous prime-boost schedules with inactivated and adenoviral vectored SARS-CoV-2 vaccines - A prospective multi-center study.

Background: During the peak of Coronavirus disease (COVID-19) pandemic in Thailand when the emergence of delta variant reduced the efficacy of inactivated vaccine, Thailand had abundance of inactivated vaccine but mRNA vaccine was not available and the supply of adenoviral-vectored vaccine was limited. The heterologous vaccination using CoronaVac and ChAdOx1-nCoV-19 vaccines was applied. We aim to compare the immunogenicity of immune response of primary vaccination with homologous ChAdOx1 nCoV-19 and heterologous vaccination with CoronaVac and ChAdOx1 nCoV-19. Methods: A total of 430 adults, scheduled to receive ChAdOx1-nCoV-19 as their second dose of primary COVID-19 vaccination, were enrolled. Participants were classified into two groups based on the first dose vaccine as CoronaVac (heterologous group) or ChAdOx1 nCoV-19 (homologous group). The primary outcome was antibodies to the SARS-CoV-2 spike protein receptor binding domain (anti-RBD) titres at 28 days after the second dose of vaccination. Secondary outcomes were anti-RBD titres at 90 days, surrogate viral neutralizing test (sVNT) at 28 and 90 days, and adverse events. Findings: In 358 participants with correct vaccine interval, the anti-RBD geometric mean titre ratio for the heterologous versus homologous group was 0.55 (95%CI; 0.44-0.067); p < 0.001 at day 28, and 0.80 (95%CI; 0.65-1.00); P = 0.05 at day 90. Median sVNT neutralizing activity was not significantly different in the heterologous versus homologous group at 28 days (93.5 vs 92.7 %); p = 0.13, but significantly higher in the heterologous group at day 90 (82.9 vs 76.4 %); p = 0.01. Interpretation: The homologous vaccination resulted in higher anti-RBD titres at 28 days after vaccination, but titres in the homologous group showed more rapid decline at 90 days. In the sVNT assay, median neutralization was similar at 28 days, but was longer-lasting and higher in the heterologous group at 90 days. Funding: This research received funding from the Royal College of Physicians of Thailand special grant 2021 for research initiative during COVID-19 pandemic.

Exertional heatstroke: early recognition and outcome with aggressive combined cooling--a 12-year experience.

OBJECTIVE: To determine the clinical outcomes of an aggressive combined cooling technique for exertional heatstroke in Thailand. METHODS: We analyzed patients who were diagnosed with exertional heatstroke between 1995 and 2007. Outcomes were assessed both in hospital and at 3 months follow-up. RESULTS: Twenty-eight cases of exertional heatstroke presented to Phramongkutklao Army Hospital over 12 years. All patients developed multiorgan dysfunction and encephalopathy. Twenty-four cases had acute renal failure, 7 of whom required dialysis. Disseminated intravascular coagulation (DIC) was detected in 9 patients (32.1%). In-hospital mortality was 7.1%. Most survivors recovered with nearly normal organ function. However, 9 exhibited prolonged neurologic dysfunction and 2 had chronic renal dysfunction requiring hemodialysis. At 3-month follow-up, neurologic and renal dysfunction in those patients persisted. Higher serum prothrombin time and DIC correlated to fatality. The patients whose core body temperature achieved 38 degrees C within 3 hours revealed a significantly lower DIC and twice as low in the frequency of poor outcome than the patients cooled longer than 3 hours to reduce core body temperature to 38 degrees C. CONCLUSIONS: Despite early recognition and aggressive combined cooling, exertional heatstroke remains associated with multiorgan dysfunction. However, our 7.1% in-hospital mortality rate was low compared to previous studies. Early diagnosis and prompt treatment are critical.

Laboratory approach in Thai patients with venous thrombosis.

This retrospective study aimed to analyze laboratory findings in Thai patients with venous thrombosis in Phramongkutklao Hospital from August 1997 to October 2004. Blood samples obtained from 166 patients with ages ranging from 10 months to 87 years were tested for protein S (PS), protein C (PC), antithrombin (AT), factor V Leiden (FVL) and prothrombin G20210A. It was found that low levels of PS, PC, and AT were observed in 23 patients (13.9%), 21 patients (12.7%) and 11 patients (6.6%), respectively. The incidence of combined low levels of anticoagulant factors occurred in 23 patients (13.9%). Three patients (1.8%) were positive for FVL. All patients were negative for prothrombin G20210A. Additionally, 85 patients (51.2%) were negative for all tests. In conclusion, it is recommended that the screening tests for anticoagulant factors PS, PC and AT be used to investigate the causes of thrombosis in Asian populations due to their cost-effectiveness. However, the detection of gene mutations inducing thrombosis should be considered.

Successful treatment of retinoic acid syndrome with dexamethasone: a case report.

Retinoic acid syndrome (RAS) is the clinical syndrome that occurs after treatment of acute promyelocytic leukemia with all-trans-retinoic acid (ATRA). The patients experience fever, dyspnea, hypotension, respiratory distress, edema and weight gain. Chest x-ray will show pulmonary infiltrates and pleuropericardial effusion. The onset of this syndrome is usually 5-21 days after ATRA treatment when white blood cell counts are rising more than 10,000/cu.mm. The authors have reported a case of RAS. The patient was a 29-year-old man who had been working in a battery manufacturing factory for 7 years. He presented with easily bruising for one month. The initial blood test showed hematocrit of 36.2%, white blood cells count of 3,200/cu.mm with 28% neutrophils, 20% lymphocytes, 2% eosinophils and 50% promyelocytes and platelet of 20,000/cu.mm. Peripheral blood smear revealed numerous fragmented red blood cells. Bone marrow examination showed hypercellularity with abnormal promyelocytes of 95% and bone marrow cytogenetics was translocation of chromosome 15 and 17 [t (15;17)(q22;q12)]. The diagnosis was acute promyelocytic leukemia and the patient was treated with ATRA 45 mg/m2/day per oral starting on day 1 and intravenous idarubicin 10 mg/n2 on day 4, 5 and 6. On day 13, he had a body temperature of 39 degrees C and a dry cough. The white blood cells were rising to 7,400/cu.mm with 16% neutrophils. On day 18, he had oliguria, high grade fever, hypotension, cough with chest pain and white blood cells rose to 21,300/cu.mm with 65% neutrophils and rising of blood urea nitrogen and creatinine. Chest x-ray showed enlarged cardiac shadow with pleural effusion. Echocardiogram revealed moderate amount of pericardial effusion. The diagnosis of RAS was made and ATRA was withdrawn. Intravenous dexamethasone 4 mg every 6 hours and hemodialysis was started. The patient's symptoms improved dramatically and bone marrow examination was in complete remission. He was subsequently given cytarabine and idarubicin as consolidation. This patient had clinical manifestation consistent with RAS, which improved after prompt treatment.

Rapid screening of PNH red cell populations using the gel test.

Paroxysmal nocturnal hemoglobinuria (PNH), an acquired clonal hematopoietic stem cell defect is underdiagnosed because of its atypical symptoms in some patients and because available methods, which are time consuming and complicated, are not widely used. The purpose of this study is to compare the results of the detection of PNH red cell populations using the PNH gel test and the Ham test. Fifty-eight blood samples obtained from 35 patients and 23 healthy blood donors were tested for PNH by the PNH gel test and the Ham test. It was found that 7 (20%) of the patients were positive for PNH by both tests. Twenty-three blood samples from healthy donors were all negative for PNH by both tests. The overall sensitivity and specificity of the gel test were 100%. This study showed that the PNH gel test was simple and could replace the Ham test as a screening test for PNH. This test would be especially easy to introduce in laboratories that are already using this system for blood grouping and antibody detection.

Factor V Leiden and prothrombin G20210A mutations in Thai patients awaiting kidney transplant.

Renal transplantation provides the best long-term treatment for chronic renal failure, but thrombosis of the transplanted renal artery or renal vein is one of the causes of kidney failure in the early postoperative period. Factor V Leiden (FVL) and prothrombin G20210A mutation are the most frequent genetic abnormalities associated with venous thrombosis. We investigated the prevalence of FVL and prothrombin G20210A by polymerase chain reaction with restriction fragment length polymorphism in 75 Thai patients awaiting renal transplant, and a control group of 106 healthy blood donors. Of those awaiting renal transplant, none was found to carry FVL or prothrombin G20210A mutations. Neither the heterozygous nor the homozygous FVL mutation nor the prothrombin G20210A mutation was detected in the 106 healthy volunteers. Although we failed to detect FVL and prothrombin G20210A mutation among those waiting for a kidney transplant, the population size was small. Further studies need to be performed in order to ascertain if these coagulation mutations are of relevance in predicting patients at risk of early transplant failure.

Comparative study of low-dose oral granisetron plus dexamethasone and high-dose metoclopramide plus dexamethasone in prevention of nausea and vomiting induced by CHOP-therapy in young patients with non-Hodgkin's lymphoma.

Standard-dose (2 mg/day) oral granisetron seems to have more antiemetic efficacy than that of high-dose (0.5-1 mg/kg/dose) metoclopramide in moderately emetogenic chemotherapy. However, the cost of oral granisetron is much higher than that of metoclopramide so the authors tried to overcome this disadvantage by dose reduction and adding dexamethasone to enhance the antiemetic effect of oral granisetron. Twenty four young patients (aged < 50 years), with non-Hodgkin's lymphoma receiving CHOP-therapy were enrolled and evaluated in a randomized, double-blind, crossover study comparing the antiemetic efficacy, toxicity and patients' preference of a combination of low-dose oral granisetron plus intravenous dexamethasone (gran/dex) with a combination of high-dose metoclopramide plus intravenous dexamethasone (met/dex) on days 1-5 after chemotherapy. The acute, delayed (day 2-5) and 5-day total control of nausea and vomiting in the gran/dex group were significantly higher than those of the met/dex group (75.0% vs 25.0%; p-value = 0.004, 79.2% vs 33.3%; p-value = 0.007 and 75.0% vs 25.0%; p-value = 0.004, respectively). Except for extrapyramidal reactions in the met/dex group, the side effects in both groups were comparable. The mean total score of antiemetic preference in the gran/dex group was also significantly higher than that of the met/dex group (9.0 vs 7.5; p-value = 0.004). In conclusion, low-dose oral granisetron combined with intravenous dexamethasone had significantly higher protective effects against both acute and delayed nausea and vomiting induced by CHOP-therapy. Thus, this regimen may be considered as an alternative outpatient antiemetic treatment for young patients with non-Hodgkin's lymphoma.