Published papers

PURPOSE: Invasive pulmonary aspergillosis (IPA) after liver transplantation (LT) is most often fatal. We analyzed the outcomes of IPA in a single center. METHODS: We reviewed, retrospectively, the medical records of recipients of living donor LT (LDLT) or deceased donor LT (DDLT) performed between 1995 and 2019 at our institute. We analyzed the incidence of IPA and assessed the treatment courses of patients treated successfully and those not treatment successfully. RESULTS: Among 326 recipients, IPA was diagnosed in 6 (1.8%). The incidence of IPA was significantly higher in patients with acute liver failure (ALF, 9.8%) than in those without ALF (0.4%), after DDLT (8.8%) than after LDLT (1.0%), and in recipients who received preoperative steroid pulse therapy (16.0%) than in those who did not (0.7%). Complete cure of IPA was achieved in the most recent three patients, by administering voriconazole immediately after the diagnosis of IPA and performing lung resection, while the IPA lesion was single and localized. CONCLUSIONS: Patients with risk factors for IPA must be monitored closely. Our three successfully treated cases demonstrate that initiating immediate voriconazole treatment and making a calculated decision about lung resection can contribute to a favorable outcome.

BACKGROUND: The risk factors for Mycobacterium avium complex lung disease (MAC-LD) are not well known. We hypothesized that low serum estradiol (E2) levels are related to MAC-LD as most patients with MAC-LD are postmenopausal women. METHODS: This cross-sectional study compared patients with MAC-LD and healthy controls. Study subjects were postmenopausal women aged 65 years or younger. Serum testosterone, dehydroepiandrosterone sulfate (DHEA-S), and E2 levels were measured and categorized as high or low based on median levels. We performed multivariate analysis, receiver operating characteristic (ROC) curve analysis, and age- and body mass index (BMI)-matched subgroup analysis to evaluate the association between low serum E2 levels and MAC-LD. Additionally, using blood samples obtained for other clinical studies, the levels of sex steroid hormones were compared between age- and BMI-matched MAC-LD and bronchiectasis female patients without non-tuberculosis mycobacterial infections (non-NTM BE). RESULTS: Forty-two patients with MAC-LD and 91 healthy controls were included. The median E2 (2.20 pg/mL vs. 15.0 pg/mL, p < 0.001), testosterone (0.230 ng/L vs. 0.250 ng/L, p = 0.005), and DHEA-S (82.5 μg/dL vs. 114.0 μg/dL, p < 0.001) levels were lower in the MAC-LD group than in the control group. Multivariate analysis revealed that low serum E2 (adjusted odds ratio = 34.62, 95% confidence interval = 6.02-199.14) was independently related to MAC-LD, whereas low DHEA-S and testosterone were not. ROC analysis illustrated a strong relationship between low serum E2 levels and MAC-LD (area under the curve = 0.947, 95% confidence interval = 0.899-0.995). Even the age- and BMI-matched subgroup analysis of 17 MAC-LD patients and 17 healthy controls showed lower serum E2 in MAC-LD patients than in healthy controls. Additionally, serum E2 levels of 20 MAC-LD patients were lower than plasma E2 levels of 11 matched non-NTM BE patients (1.79 pg/mL vs. 11.0 pg/mL, p < 0.001). CONCLUSIONS: Low serum E2 levels were strongly related to MAC-LD in postmenopausal women.

Here, we describe a rare case of malignant lymphoma after liver transplantation for liver cirrhosis caused by human immunodeficiency virus (HIV) and hepatitis C virus (HCV) co-infection. A male patient was diagnosed with hemophilia A at 8 months of age. Since then, he had been receiving blood products, which led to HIV and HCV co-infection. His HIV viral load was suppressed with antiretroviral therapy, and a sustained virologic response was achieved for HCV using direct-acting antivirals. However, his decompensated liver cirrhosis progressed, and deceased donor liver transplantation was performed. A post-transplant lymphoproliferative disorder (PTLD) developed 105 days after liver transplantation, with enlarged para-aortic and hilar lymph nodes, a right renal mass, and masses in the small and large intestines. Histopathological examination confirmed monomorphic PTLD (diffuse large B-cell lymphoma). Against the treatment (reduction of immunosuppression, rituximab, and chemotherapy), the response was poor, and the patient died 94 days after the outbreak of PTLD. Both transplantation and HIV infection are risk factors for lymphoproliferative diseases. To the best of our knowledge, this is one of the very few reports of PTLD in a patient with HIV/HCV co-infection.

Locally advanced cervical cancer occasionally induces pyometra, but there have been no reports of meningitis where pyometra is the cause of infection. Here, we report a case of Listeria monocytogenes meningitis related to pyometra during concurrent chemoradiotherapy (CCRT) in a cervical cancer patient. The patient, a 77-year-old woman, was diagnosed with Stage IIB (FIGO 2018) cervical adenocarcinoma, and CCRT was initiated. Pyometra was exacerbated during CCRT, and after her first brachytherapy, she presented at our hospital with fever and decreased consciousness level. After admission to the Intensive Care Unit, the patient lost consciousness and experienced frequent seizures; tracheal intubation was required. Whole-body computed tomography revealed pyometra; therefore, transvaginal removal of the abscess was performed. Laboratory tests and vital signs indicated septic shock, and meropenem was administered. L. monocytogenes was detected in the abscess from the uterine cavity and the blood cultures on the third day of hospitalization. A lumbar puncture was performed on the same day to investigate whether the patient had meningitis. A FilmArray meningitis/encephalitis panel test of the spinal fluid revealed L. monocytogenes. After the diagnosis of meningitis with L. monocytogenes, ampicillin and gentamicin were started, and the blood test results gradually improved. Five months after the initial episode, her consciousness recovered, however she still received mechanical ventilatory support. L. monocytogenes infections can occur in patients undergoing chemotherapy, even without the use of steroids or immunosuppressive agents. In cases with pyometra, intrauterine manipulation can increase the risk of severe infection.

INTRODUCTION: Migraine pharmacological therapies targeting calcitonin gene-related peptide (CGRP), including monoclonal antibodies and gepants, have shown clinical effect and optimal tolerability. Interactions between treatments of COVID-19 and CGRP-related drugs have not been reviewed. AREAS COVERED: An overview of CGRP, a description of the characteristics of each CGRP-related drug and its response predictors, COVID-19 and its treatment, the interactions between CGRP-related drugs and COVID-19 treatment, COVID-19 and vaccination-induced headache, and the neurological consequences of Covid-19. EXPERT OPINION: Clinicians should be careful about using gepants for COVID-19 patients, due to the potential drug interactions with drugs metabolized via CYP3A4 cytochrome. In particular, COVID-19 treatment (especially nirmatrelvir packaged with ritonavir, as Paxlovid) should be considered cautiously. It is advisable to stop or adjust the dose (10 mg atogepant when used for episodic migraine) of gepants when using Paxlovid (except for zavegepant). CGRP moncolconal antibodies (CGRP-mAbs) do not have drug - drug interactions, but a few days' interval between a COVID-19 vaccination and the use of CGRP mAbs is recommended to allow the accurate identification of the possible adverse effects, such as injection site reaction. Covid-19- and vaccination-related headache are known to occur. Whether CGRP-related drugs would be of benefit in these circumstances is not yet known.

BACKGROUND: Since nontuberculous mycobacterial pulmonary disease (NTM-PD) is common in middle-aged/elderly slender women at risk of osteoporosis, we hypothesized that NTM-PD could be associated with osteoporosis. The study aimed to evaluate the prevalence of osteoporosis in patients with NTM-PD compared with that in the general population and determine the factors associated with osteoporosis in the subjects, including the serum estradiol (E2) and 25-hydroxyvitamin D (25OHD) levels. METHODS: We have recruited 228 consecutive adult patients with NTM-PD from a prospective cohort study at the Keio University Hospital, who had no history of osteoporosis or osteoporosis-associated bone fracture but underwent dual-energy X-ray absorptiometry-based bone mineral density (BMD) evaluation from August 2017-September 2019. The E2 and 25OHD levels were measured in 165 patients with available stored serum samples. We performed multivariable logistic regression analyses for osteopenia and osteoporosis. RESULTS: Osteoporosis (T-score ≤  - 2.5) and osteopenia (T-score - 1 to - 2.5) were diagnosed in 35.1% and 36.8% of patients with NTM-PD, respectively. Compared with the general population, the proportion of osteoporosis was significantly higher in 50-59-, 60-69-, and 70-79-year-old women with NTM-PD. Multivariable analysis revealed that older age (adjusted odds ratio [aOR] for 1-year increase = 1.12; 95% confidence interval [CI] = 1.07-1.18), female sex (aOR = 36.3; 95% CI = 7.57-174), lower BMI (aOR for 1 kg/m2 decrease = 1.37; 95% CI = 1.14-1.65), and chronic Pseudomonas aeruginosa (PA) infection (aOR = 6.70; 95% CI = 1.07-41.8) were independently associated with osteoporosis. Additionally, multivariable analysis in 165 patients whose serum E2 and 25OHD levels were measured showed that both low E2 levels (< 10 pg/mL) and lower 25OHD levels were independently associated with osteoporosis. CONCLUSIONS: Middle-aged/elderly women with NTM-PD have a higher prevalence of osteoporosis than the general population. BMD screening should be considered in NTM-PD, especially in older females with severe diseases such as chronic PA infection and lower BMI, and low serum E2 and 25OHD levels.

OBJECTIVES: To determine the usefulness of hsa-miR-346, a potential biomarker enhancing the activity of non-tuberculous mycobacterial diseases, as a biomarker of tuberculosis activity. METHODS: We investigated whether hsa-miR-346 is secreted by human macrophages infected with Mycobacterium tuberculosis (M. tuberculosis) in an in vitro study. In addition, a cross-sectional study was conducted first to evaluate whether serum hsa-miR-346 is elevated in patients with tuberculosis compared with that in healthy individuals. Second, we conducted a retrospective study to evaluate whether anti-tuberculosis treatment reduces serum hsa-miR-346 levels. RESULTS: Log hsa-miR-346 levels were significantly elevated in the supernatant of human macrophages infected with M. tuberculosis in a dose-dependent manner. The mean serum log hsa-miR-346 levels were -15.48 (-15.76 to -15.21) in patients with tuberculosis and -16.12 (-16.29 to -15.95) in healthy volunteers, which significantly differed. In addition, hsa-miR-346 significantly decreased at 2 months from starting an anti-tuberculosis treatment. CONCLUSIONS: We consider hsa-miR-346 as a potential biomarker enhancing the tuberculosis activity.

SARS-CoV-2 genome accumulates point mutations constantly. However, whether non-synonymous mutations affect COVID-19 severity through altering viral protein function remains unknown. SARS-CoV-2 genome sequencing revealed that the number of non-synonymous mutations correlated inversely with COVID-19 severity in Tokyo Metropolitan area. Phylogenic tree analyses identified two predominant groups which were differentiated by a set of six-point mutations (four non-synonymous amino acid mutations). Among them, Pro108Ser in 3 chymotrypsin-like protease (3CLpro) and Pro151Leu in nucleocapsid protein occurred at conserved locations among β-coronaviruses. Patients with these mutations (N = 48) indicated significantly lower odds ratio for developing hypoxia which required supplemental oxygen (odds ratio 0.24 [95% CI 0.07-0.88, p-value = 0.032]) after adjustments for age and sex, versus those lacking this haplotype in the canonical Clade 20B (N = 37). The Pro108Ser 3CLpro enzyme in vitro decreases in the activity by 58%, and the hydrogen/deuterium exchange mass spectrometry reveals that mechanisms for reduced activities involve structural perturbation at the substrate-binding region which is positioned behind and distant from the 108th amino acid residue of the enzyme. This mutant strain rapidly outcompeted pre-existing variants to become predominant in Japan. Our results may benefit the efforts underway to design small molecular compounds or antibodies targeting 3CLpro.

Recently, an international randomized controlled clinical trial showed that patients with SARS-CoV-2 infection treated orally with the 3-chymotrypsin-like protease (3CLpro) inhibitor PF-07321332 within three days of symptom onset showed an 89% lower risk of COVID-19-related hospital admission/ death from any cause as compared with the patients who received placebo. Lending support to this critically important result of the aforementioned trial, we demonstrated in our study that patients infected with a SARS-Cov-2 sub-lineage (B.1.1.284) carrying the Pro108Ser mutation in 3CLpro tended to have a comparatively milder clinical course (i.e., a smaller proportion of patients required oxygen supplementation during the clinical course) than patients infected with the same sub-lineage of virus not carrying the mutation. Characterization of the mutant 3CLpro revealed that the Kcat/Km of the 3CLpro enzyme containing Ser108 was 58% lower than that of Pro108 3CLpro. Hydrogen/deuterium-exchange mass spectrometry (HDX-MS) revealed that the reduced activity was associated with structural perturbation surrounding the substrate-binding region of the enzyme, which is positioned behind and distant from the 108th amino acid residue. Our findings of the attenuated clinical course of COVID-19 in patients infected with SARS-CoV-2 strains with reduced 3CLpro enzymatic activity greatly endorses the promising result of the aforementioned clinical trial of the 3CLpro inhibitor.

A 77-year-old Japanese man with disseminated Mycobacterium avium complex (MAC) disease due to anti-interferon-gamma autoantibodies received rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) chemotherapy because of non-Hodgkin lymphoma complication. The hepatobiliary nodules due to MAC resolved with R-CHOP and multidrug antimycobacterial treatment. R-CHOP could serve as an alternative adjunctive therapy for patients with anti-interferon-gamma autoantibodies.

BACKGROUND: There is no proven management for mild cases of Mycobacterium avium complex (MAC) pulmonary disease, who do not immediately receive treatment and are managed with observation alone, because its long term-natural course, factors predictive of deterioration, and the effect of treating the disease remain unclear. Thus, we sought to investigate the natural course of mild cases of MAC pulmonary disease. METHODS: We conducted a multicenter retrospective study. Sixty-five patients with mild MAC pulmonary disease in whom treatment was withheld for at least 6 months after diagnosis were retrospectively recruited after a review of 747 medical records. Longitudinal changes in clinical features were evaluated by using a mixed effects model. RESULTS: Mean follow-up was 6.9 ± 5.7 years. During the follow-up period, 15 patients (23%) required treatment and 50 (77%) were managed with observation alone. At diagnosis, 65 patients had nodular bronchiectatic disease without fibrocavitary lesions. Among clinical features, mean body mass index (BMI), forced expiratory volume in 1 second as percent of forced vital capacity (%FEV1), nodular lung lesions, and bronchiectasis worsened significantly in the observation group during follow-up. In the treatment group, BMI, and %FEV1 were stable, but bronchiectasis significantly worsened. At diagnosis, the polyclonal MAC infection rate in the treatment group was higher than that in the observation group. Other microbiological factors, such as insertion sequences, did not differ significantly between the groups. CONCLUSIONS: Mild MAC pulmonary disease progresses slowly but substantially without treatment. Treatment prevents the deterioration of the disease but not the progression of bronchiectasis. Polyclonal MAC infection is a predictor of disease progression.

INTRODUCTION: According to the Japanese guidelines for the management of Clostridioides difficile infection (CDI), the first choice is metronidazole (MNZ) for non-severe cases and vancomycin (VCM) for severe cases. However, the appropriateness of this first choice in Japanese patients is unclear. We therefore evaluated the appropriateness of the CDI management guidelines and the incidence of adverse drug reactions. METHODS: The electronic chart data at Keio University Hospital between January 2012 and June 2019 were retrospectively reviewed. The response rate, the relapse rate, and the adverse reaction rate of treatment for CDI using MNZ or VCM were investigated according to the disease severity. Factorial analysis associated with the response, relapse, and adverse reaction was also performed. RESULTS: In the 352 patients surveyed, no significant difference was observed in the response rate between MNZ and VCM regardless of the severity of CDI. The presence of cancer was a factor related to the persistence of diarrheal symptoms and older age was a risk factor for relapse. MNZ induced nausea significantly more frequently than VCM, and young age and female sex were risk factors for nausea. CONCLUSION: As no significant difference was observed in the response rate of CDI between MNZ and VCM, the Japanese CDI management guidelines, which recommend MNZ as the first choice, were demonstrated to be appropriate. Attention to nausea was also suggested to be necessary when administering MNZ to young females.

OBJECTIVES: The infectious diseases team at Kameda Medical Center, Japan, implemented a new outpatient parenteral antimicrobial therapy (OPAT) program in July 2012 and expanded the program with the support of home care services. This study reviews the OPAT program after 5.5 years of operation. METHODS: We prospectively collected data about the age, sex, diagnoses, causative organisms, types of OPAT, modes of administration, selected antibiotics, treatment durations, bed days saved, outcomes, readmissions, and estimated cost reductions of all patients who were treated in the OPAT program from July 2012 to December 2017. RESULTS: Of the 66 patients treated under the OPAT program, 45 (68.2%) were treated using clinic OPAT, and 21 (31.8%) were treated using homecare OPAT. The most commonly targeted organism was methicillin-susceptible Staphylococcus aureus. Continuous infusion with elastomeric pumps was employed in 55 patients (83.3%). Cefazolin was the most frequently used antibiotic (39.4%), followed by penicillin G (24.2%). The median OPAT duration was 13 days (range, 3-51), and the total bed days saved was 923. The estimated medical cost reduction was approximately 87,000 US dollars. CONCLUSIONS: Our experience shows that OPAT is a safe and feasible practice not only for efficient bed utilization and medical cost savings but also for better antimicrobial stewardship.