Increase in antibody titer and change over time associated with severe acute respiratory syndrome coronavirus 2 infection after mRNA vaccination: Consideration of the significance of additional vaccination.

Key Clinical Message: Most Japanese patients naturally infected with COVID-19 were infected after mRNA vaccination, and many maintained high antibody titers due to hybrid immunity. The significance of additional vaccination in hybrid-immunized cases is highly questionable. Abstract: Spontaneous infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) after mRNA vaccination causes a marked increase in antibody titer because of the combined effect of vaccine and infection ("hybrid immunity"). In this study, we discuss the significance of the mRNA vaccine booster inoculation that has been repeatedly performed in Japan. We describe the temporal trends of antibody titers in cases in which antibody titers were markedly increased by hybrid immunization. The antibody titer increased with hybrid immunization and tended to decrease with time. However, several cases maintained high antibody titers for approximately 1 year after coronavirus disease 2019 (COVID-19) diagnosis, even without booster vaccination. Most Japanese patients naturally infected with COVID-19 were infected after mRNA vaccination, and many maintained high antibody titers due to hybrid immunity. The significance of additional vaccination in hybrid-immunized cases is highly questionable regarding cost-effectiveness and risk-benefit.

Longitudinal Changes in IgG-Type SARS-CoV-2 Antibody Titers after COVID-19 Vaccination and a Prominent Increase in Antibody Titers When Infected after Vaccination.

OBJECTIVE: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody titers level and duration of elevated levels are considered important indicators for confirming the efficacy of coronavirus disease 2019 (COVID-19) vaccines. The objective of this study was to demonstrate the changes in antibody titers after the second and third doses of the COVID-19 vaccine, and to determine the antibody titers in cases of spontaneous infection with SARS-CoV-2 after vaccination. MATERIALS AND METHODS: From June 2021 to February 2023, IgG-type SARS-CoV-2 antibody titers were measured in 127 participants, including 74 outpatients and 53 members of staff, at the Osaka Dental University Hospital (64 males and 63 females, mean age 52.3 ± 19.0 years). RESULTS: Consistent with previous reports, the SARS-CoV-2 antibody titer decreased with time, not only after the second dose but also after the third dose of the vaccine if there was no spontaneous COVID-19 infection. We also confirmed that the third booster vaccination was effective in increasing the antibody titer. A total of 21 cases of natural infections were observed after administering two or more doses of the vaccine. Thirteen of these patients had post-infection antibody titers exceeding 40,000 AU/mL, and some cases continued to maintain antibody titers in the tens of thousands of AU/mL even after more than 6 months had passed since infection. CONCLUSIONS: The rise in and duration of antibody titers against SARS-CoV-2 are considered important indicators for confirming the efficacy of novel COVID-19 vaccines. A longitudinal follow-up of antibody titers after vaccination in larger studies is warranted.

Trends in Antibody Titers after SARS-CoV-2 Vaccination-Insights from Self-Paid Tests at a General Internal Medicine Clinic.

Background: The rise in antibody titers against the novel coronavirus (SARS-CoV-2) and its duration are considered an important indicator for confirming the effect of a COVID-19 vaccine, and self-paid tests of antibody titer are conducted in many facilities nationwide. Methods: The relationship between the number of days after the second and third dose of vaccines, age, and antibody titer was determined from the medical records of general internal medicine clinics that conducted self-paid testing of the SARS-CoV-2 antibody titer using Elecsys Anti-SARS-CoV-2 S (Roche Diagnostics); the relationship between the number of days after two or more doses of vaccines and antibody titer was also determined. We also examined the antibody titers in cases of spontaneous infection with SARS-CoV-2 after two or more doses of the vaccine. Results: Log-transformed SARS-CoV-2 antibody titers measured within 1 month from the second or third dose of vaccine showed a negative correlation with age (p < 0.05). In addition, the log-transformed antibody titers also showed a negative correlation trend with the number of days after the second dose of vaccine (p = 0.055); however, there were no significant correlations between the log-transformed antibody titers and the number of days after the third dose of vaccine. The median antibody titer after the third vaccination was 18,300 U/mL, more than 10 times the median antibody titer after the second dose of vaccine, of 1185 U/mL. There were also some cases of infection after the third or fourth dose of vaccine, with antibody titers in the tens of thousands of U/ml after infection, but the patients still received further booster vaccinations after the infection. Conclusions: The antibody titers after the third vaccination did not attenuate after a short follow-up period of one month, while they tended to attenuate after the second vaccination. It is considered that many people in Japan received further booster vaccinations after spontaneous infection, even though they already had antibody titers in the tens of thousands of U/mL due to "hybrid immunity" after spontaneous infection following two or more doses of vaccine. The clinical significance of the booster vaccination in this population still needs to be thoroughly investigated and should be prioritized for those with low SARS-CoV-2 antibody titers.

Association between oral frailty and cystatin C-related indices-A questionnaire (OFI-8) study in general internal medicine practice.

BACKGROUND: Cystatin C-related indices such as the ratio of creatinine to cystatin C (Cr/CysC) and the ratio of estimated glomerular filtration rate by cystatin C (eGFRcys) to creatinine eGFRcre (eGFRcys/eGFRcre) levels have been shown to be associated with muscle mass and strength and can be markers of sarcopenia. Oral frailty is defined as an age-related gradual loss of oral functions, accompanied by a decline in cognitive and physical functions. It results in adverse health-related outcomes in older age, including mortality, physical frailty, functional disability, poor quality of life, and increased hospitalization and falls. Therefore, poor oral health among the elderly is an important health concern due to its association with the pathogenesis of systemic frailty, suggesting it to be a multidimensional geriatric syndrome. The Oral Frailty Index-8 (OFI-8) is a questionnaire that can be used for easy screening of oral frailty. This study aimed to investigate whether cystatin C- related indices are different between patients with low to moderate risk of oral frailty and those at high risk of oral frailty, using the OFI-8 in attending a general internal medicine outpatient clinic. MATERIALS AND METHODS: This is a cross-sectional study that included 251 patients with a mean age of 77.7±6.6 years and a median age of 77 years (128 men: mean age, 77.1±7.3 years; median age, 77 years and 123 women: mean age, 78.4±5.7 years; median age, 78 years) attending general internal medicine outpatient clinics. OFI-8 scores were tabulated by gender to determine whether there were differences between patients at low to moderate risk of oral frailty (OFI-8 score ≤3 points) and those at high risk (OFI-8 score ≥4 points) in Cr/CysC, eGFRcys/eGFRcre levels, height, weight, grip strength, etc. were examined. RESULTS: The OFI-8 score was higher in women than in men, suggesting that oral frailty is more common in women. Cr/CysC, eGFRcys/eGFRcre and grip strength were significantly lower in both men and women in the high-risk group for oral frailty (OFI-8 score ≥ 4). Height, hemoglobin level, red blood cell count, and serum albumin levels were significantly lower in men with an OFI-8 score ≥4. Receiver operating characteristic curve (ROC) analysis also showed that Cr/CysC and eGFRcys/eGFRcre were significantly associated with an OFI-8 score≥4 in both men and women. CONCLUSION: Cr/CysC and eGFRcys/eGFRcre were significantly lower in the high-risk group for oral frailty on the OFI-8in both men and women. A relationship exists among cystatin C-related indices, which can effectively screen systemic frailty. Similarly, the OFI-8 score can be used to effectively screen oral frailty. Thus, a collaboration that incorporates both systemic and oral frailty from medical and dental perspectives is required.

[An autopsy of a case of pulmonary hypertension secondary to pulmonary embolization of intrahepatic cholangiocarcinoma].

A 70-year-old woman was admitted to our hospital for one month because of progressive dyspnea. Her medical history included an operation for hepatolithiasis at age 47. She was a current smoker. Chest CT revealed emphysematous change and honeycombing in the lung and bilateral subpleural opacifications. Cardiac ultrasound examination showed pulmonary hypertension. Treatments with antibiotics, corticosteroids and heparin were unsuccessful. Despite mechanical ventilation, she died of respiratory failure. Autopsy revealed that intrahepatic cholangiocarcinoma had spread via the hematogeneous route, formed multiple emboli into the pulmonary small arteries, and led to severe pulmonary hypertension and lung infarction.

Effects of ghrelin treatment on exercise capacity in underweight COPD patients: a substudy of a multicenter, randomized, double-blind, placebo-controlled trial of ghrelin treatment.

BACKGROUND: The aim of this substudy of the ghrelin treatment, multicenter, randomized, double-blind, placebo-controlled trial was to investigate the effects of ghrelin administration on exercise capacity and the underlying mechanisms in underweight patients with chronic obstructive pulmonary disease (COPD) using cardiopulmonary exercise testing. METHODS: Twenty underweight COPD patients were randomized to pulmonary rehabilitation with intravenous ghrelin (2 µg/kg, n = 10) or placebo (n = 10) twice daily for 3 weeks in a double-blind fashion. The primary outcome was changes in peak oxygen uptake V•o2. Secondary outcomes included changes in exertional cardio-respiratory functions: O2-pulse, physiologic dead space/tidal volume-ratio (VD/VT), ventilatory equivalent for oxygen V•E/V•o2, and ventilatory equivalent for carbon dioxide V•E/V•co2. RESULTS: With incremental exercise, at peak exercise, there was a significant difference in the mean difference (ghrelin minus placebo), i.e., treatment effect in: i) peak V•o2 (1.2 mL/kg/min, 95% CI: 0.2-2.3 mL/kg/min, between-group p = 0.025); ii) V•E/V•o2 (-4.2, 95% CI: -7.9 to -0.5, between-group p = 0.030); iii) V•E/V•co2 (-4.1, 95% CI: -8.2 to -0.1, between-group p = 0.045); iv) VD/VT (-0.04, 95% CI: -0.08 to -0.00, between-group p = 0.041); and v) O2-pulse (0.7 mL/beat, 95% CI: 0.3 to 1.2 mL/beat, between-group p = 0.003). Additionally, repeated-measures analysis of variance (ANOVA) indicated a significant time-course effect of ghrelin versus placebo in the peak V•o2 (p = 0.025). CONCLUSION: Ghrelin administration was associated with improved exertional capacity and improvements in ventilatory-cardiac parameters. TRIAL REGISTRATION: UMIN (University Hospital Medical Information Network in Japan) C000000061.

[Susceptibility to rifabutin and novel fluoroquinolones in Mycobacterium avium complex isolates from patients with sputum culture-positive pulmonary disease who are undergoing standard chemotherapy].

We investigated the susceptibility to conventional and newer antimycobacterial agents including rifabutin (RBT) and novel fluoroquinolones (NFQs) among 48 clinical Mycobacterium avium complex (MAC) isolates from patients with sputum culture-positive MAC disease who were undergoing standard chemotherapy. RBT and NFQs were superior to conventional agents because of higher rates of susceptibility and lower minimum inhibitory concentration. NFQs showed cross-resistance among quinolones. In contrast, RBT did not show cross-resistance to RFP. Most clarithromycin-resistant or rifampicin-resistant cases were susceptible to RBT and NFQs. In conclusion, RBT and NFQs possess good in vitro antimicrobial activity among clinical isolates of culture-positive pulmonary MAC disease, which suggests that a combination of such microbiologically active agents may improve clinical effectiveness more than standard chemotherapy regimens.

Exertional dyspnea-related acidotic and sympathetic responses in patients with sequelae of pulmonary tuberculosis.

The objective of this study was to investigate whether exertional dyspnea correlates with exercise responses, especially arterial blood pH and plasma norepinephrine (NE) changes, in patients with sequelae of tuberculosis (TBsq). Cardiopulmonary exercise testings were performed in 49 TBsq patients and 9 controls. Each group had a break point in the dyspnea, plasma lactate, and plasma NE changes during exercise, all of which occurred at a similar exercise point. In TBsq patients in both exercise phases before and after the dyspnea break point, the dyspnea-slope (DeltaBorg scale/Deltaminute ventilation) correlated with the pH-slope (DeltapH/Deltaoxygen uptake) (r = -0.616, p < 0.0001; r = -0.629, p < 0.0001, respectively, before and after the break point) and with the NE-slope (DeltaNE/Deltaoxygen uptake) (r = 0.443, p = 0.0012; r = 0.643, p < 0.0001, respectively, before and after the break point). In TBsq patients during exercise, increases in circulating NE levels and exertional acidosis were correlated with exertional dyspnea.

Acidosis and raised norepinephrine levels are associated with exercise dyspnoea in idiopathic pulmonary fibrosis.

BACKGROUND AND OBJECTIVE: Exertional dyspnoea limits patients with IPF in their activities of daily living. The mechanism, however, has not been elucidated. This study tested the hypothesis in IPF that exertional dyspnoea correlates with cardiopulmonary exercise responses, specifically changes in arterial blood pH and plasma norepinephrine (NE). METHODS: Cardiopulmonary exercise testing with measurements of dyspnoea (Borg scale), plasma NE, plasma lactate and arterial blood gases were performed in 29 patients with IPF and in nine controls. RESULTS: Both groups showed obvious break points in dyspnoea changes during exercise. In IPF, an abrupt change in the Borg scale, pH, PaCO(2) and plasma NE occurred in the late exercise phase after the 'break point'. Compared with controls, patients with IPF had significantly higher HCO(3)(-) levels and physiologic dead space/tidal volume during exercise. In IPF, during both exercise phases, the dyspnoea slope (DeltaBorg scale/Deltaminute ventilation) correlated with the pH slope (DeltapH/Deltaoxygen uptake) (before the break point: r = -0.537, P = 0.0022; r = -0.886, P < 0.0001, after the break point) and the NE slope (DeltaNE/Deltaoxygen uptake) (before the break point: r = 0.481, P = 0.0075; R = 0.784, P < 0.0001, after the break point). CONCLUSIONS: In patients with IPF, exercise-induced acidosis and increases in circulating NE levels were associated with intensity of exertional dyspnoea.

The degree of exercise hypoxemia reflects pulmonary artery pressure during early exercise in chronic obstructive pulmonary disease patients.

The causes of both exertional pulmonary hypertension and pulmonary hypertension in general in chronic obstructive pulmonary disease (COPD) remain to be elucidated. To further understand the pathophysiology in COPD patients, it may be important to recognize the existence of exertional pulmonary hypertension and to determine the severity of exertional hypoxemia. However, little is known about their relationship. To investigate whether the severity of exertional hypoxemia, as evaluated by the Deltaartery oxygen tension/Deltaoxygen consumption (PaO(2)-slope) correlates with the mean pulmonary artery pressure (Ppa), cardiopulmonary exercise testing with haemodynamics was done in 10 patients with moderate to very severe COPD. The PaO(2)-slope was significantly correlated with the mean Ppa from 25% to 40% of the maximum Watts (Wmax), and was most significant at 30% Wmax (r = -0.904, P<0.0001). In this phase, all parameters, except for the mean Ppa and the mixed venous oxygen tension, were not markedly changed from resting levels. At 30% Wmax, the mean Ppa (mean, 27 mmHg) with no or mild hypoxemia was also significantly correlated with the Deltaartery oxygen saturation/Deltaoxygen consumption (SpO(2)-slope) (r = -0.789, P = 0.004). On stepwise multiple regression analysis, the PaO(2)-slope was the most significant predictor of mean Ppa at 30% Wmax. In conclusion, the PaO(2)-slope and the SpO(2)-slope reflect Ppa during the early exercise phase. Thus, assessment of these parameters could be useful to evaluate the cardiopulmonary haemodynamic pathophysiology of COPD patients.

[A case of spontaneous resolution of sarcoidosis with primary pulmonary cavitations].

On routine physical checkup, a 27-year-old man with productive cough was found to have multiple nodules with cavitation in the bilateral lung fields and mediastinal and hilar lymph adenopathy on chest X-ray film and CT scan. Serum levels of angiotensin converting enzyme and lysozyme were high. Tuberculin reaction was negative. Non-caseous epitheloid granulomas were confirmed in the bronchial wall specimens obtained by trans-bronchial biopsy. The number of lymphocytes and the CD4/CD8 ratio of lymphocytes in bronchoalveolar lavage fluid was increased. Therefore, pulmonary sarcoidosis was diagnosed, and the lung nodules with cavitation were considered due to sarcoidosis. The walls of the cavitations gradually thinned and had almost completely vanished after 6 months of careful observation without steroid therapy.

[A case of pneumonitis suspected to be induced by Oseltamivir].

A 33-year-old man had a high fever and was given Cefcapene and Oseltamivir without a definite diagnosis of influenza. Three days later an abnormal chest shadow was pointed out. Chest CT revealed ground-glass opacities and air-space consolidation in bilateral lung fields. Although he was given antibiotics, lung infiltrates increased and his symptoms worsened. Therefore, he was transferred to our hospital. Corticosteroid pulse-therapy resulted in prompt improvement of chest infiltrates and his symptoms. The drug-induced lymphocyte stimulating test results indicated 170% of oseltamivir and 150% of cefcapene. Considering the clinical course and laboratory data, this was probably drug-induced lung injury caused by oseltamivir.

Infective tricuspid valve endocarditis with pulmonary emboli caused by Campylobacter fetus after tooth extraction.

We describe a case of infective endocarditis caused by Campylobacter fetus accompanied by pulmonary emboli. A 52-year-old man was referred to our hospital due to febrile temperatures with a history of dental treatment followed by eating raw meat. Computed tomography revealed multiple infiltrations and a nodule with low attenuation area and feeding vessels. A mobile mass, possible vegetation, attached to the tricuspid valve was detected by transthoracic echocardiography. Two blood cultures disclosed Campylobacter fetus. Long-term antibiotic therapy was given, curing the infection with valvuloplasty. We presented the possibility that infective Campylobacter fetus endocarditis after dental treatment was caused by eating raw meat.

Association between hepatocyte growth factor gene polymorphism and essential hypertension.

Hepatocyte growth factor (HGF) is a growth factor which contributes to protection and/or repair of vascular endothelial cells. Serum HGF level is elevated in response to hypertensive organ damage, which suggests that blood pressure regulation may be affected by HGF gene polymorphisms via serum HGF. To examine the interaction between a HGF gene polymorphism and hypertension, we carried out a case-control study. The present study was conducted in outpatients of Osaka University Hospital. Subjects (n=654) who gave informed consent to the study protocol and genetic analysis were recruited. A C to A nucleotide substitution in intron 13 of the HGF gene was determined by the TaqMan polymerase chain reaction (PCR) method using an MGB (Minor Groove Binder) probe. The genotype distribution of the C/A polymorphism of the HGF gene in total subjects was as follows: CC, 83%; CA, 16%; and AA 1%. This distribution was not significantly different from the predicted by Hardy-Weinberg's equilibrium. The prevalence of hypertension was significantly higher in subjects with the CC genotype than in those with an A allele, and the positive association remained after adjustment for confounding factors, with the estimated odds ratio for hypertension (CC vs. CA+AA) being 1.71 (95% confidence interval: 1.02-2.93). A significant association with hypertension was observed in lean or female subjects but not in obese or male subjects. In conclusion, our data suggested that C/A polymorphism in intron 13 of the HGF gene is associated with susceptibility to essential hypertension in lean or female subjects.

Hypoadiponectinemia is an independent risk factor for hypertension.

Adiponectin is one of the key molecules in the metabolic syndrome, and its concentration is decreased in obesity, type-2 diabetes, and coronary artery disease. Genetic investigation has revealed that 2 polymorphisms (I164T and G276T) are related to adiponectin concentration and diabetes. To examine whether adiponectin affects hypertension genetically or biologically, we performed a case-control study. A total of 446 diagnosed cases of hypertension (HT) in men and 312 normotensive (NT) men were enrolled in this study. Plasma adiponectin concentration was measured using an enzyme-linked immunosorbent assay system. Single nucleotide polymorphisms were determined by TaqMan polymerase chain reaction method. After adjustment for confounding factors, adiponectin concentration was significantly lower in HT (HT: 5.2+/-0.2 microg/mL; NT: 6.1+/-0.2 microg/mL; P<0.001). Furthermore, multiple regression analysis indicated that hypoadiponectinemia was an independent risk factor for hypertension (P<0.001). Blood pressure was inversely associated with adiponectin concentration in normotensives regardless of insulin resistance. In subjects carrying the TC genotype of the I164T polymorphism, adiponectin concentration was significantly lower (TC: 2.6+/-0.9 microg/mL; TT: 5.5+/-0.1 microg/mL; P<0.01), and most of them had hypertension. In contrast, the G276T polymorphism was not associated with adiponectin concentration or hypertension. In conclusion, hypoadiponectinemia is a marker for predisposition to hypertension in men.

alpha-Adducin Gly460Trp polymorphism is associated with low renin hypertension in younger subjects in the Ohasama study.

BACKGROUND: The Gly460Trp polymorphism of the alpha-adducin gene (ADD-1 ) has been examined as a candidate gene for essential hypertension with salt sensitivity in the Caucasian population. However, we failed to detect a positive association between the Gly460Trp polymorphism of ADD-1 and hypertension in a small series of Japanese subjects. OBJECTIVE: To examine the precise association between the Gly460Trp polymorphism of ADD-1 and blood pressure (BP), we carried out an association study using a Japanese population: the Ohasama Study. DESIGN: Subjects (n = 1490) were recruited from participants in the Ohasama Study, which is a cohort in a rural community of northern Japan. METHODS: DNA was extracted from the buffy coat of the participants who gave informed consent for genetic analysis, and the Gly460Trp polymorphism of ADD-1 was determined by the TaqMan polymerase chain reaction method. Various BP values (casual BP, ambulatory BP and home BP) were measured in the Ohasama study. We used the mean values of these BP measurements for analysis. RESULTS: The frequencies of genotypes in the Ohasama population were 23% Gly/Gly, 49% Gly/Trp, and 28% Trp/Trp. In the baseline characteristics, age, sex, body mass index, frequency of diabetes and hyperlipidemia were significantly different between hypertensive or normotensive subjects. In total subjects, all BP values were not different among genotypes. In the younger subjects ( 60 years old) with low plasma renin activity (< 1.0 ng/ml per h), however, ambulatory BP and home BP were significantly higher in the subjects with the Gly/Trp or Trp/Trp genotypes of ADD-1 polymorphism than in those with the Gly/Gly genotype. In the same population, the frequency of the Gly/Trp or Trp/Trp genotypes of was significantly higher in hypertensives than in normotensives (83 versus 72%, chi1(2) = 4.04, P<0.05; odds ratio, 2.12; 95% confidence interval, 1.02-4.68). CONCLUSIONS: These findings suggest the possibility that the Gly460Trp polymorphism of ADD-1 is associated with low renin hypertension.