Longitudinal long COVID symptoms in Japanese patients after COVID-19 vaccinations.

We conducted a subgroup analysis of a study on the long-term effects of COVID-19 (long COVID) in Japan to assess the effect of vaccination on long COVID symptoms. We assessed the clinical course of 111 patients with long COVID at the time of vaccination. The follow-up period was one year from the onset of COVID-19 or until the administration of the third vaccine dose. Of the 111 patients, 15 (13.5%) reported improvement, four (3.6%) reported deterioration, and 92 (82.9%) reported no change in their long COVID symptoms after vaccination. The most common long COVID symptoms before vaccination were alopecia, dyspnea, muscle weakness, fatigue, and headache among participants whose symptoms improved. Reduced dyspnea and alopecia were the most frequently reported improvements in symptoms after vaccination. Some symptoms persisted, including sleep disturbance, myalgia, and hypersensitivity. Vaccination did not appear to have a clinically important effect on patients with long COVID symptoms.

An independent prognostic factor in surgical cases of pleural empyema caused by common bacteria is the presence of a fistula.

OBJECTIVES: Some surgical cases of pleural empyema lead to death despite multidisciplinary treatment. The purpose of this study was to identify prognostic factors in cases treated surgically for pneumonia-associated pleural effusions and empyema caused by common bacteria. METHODS: We conducted a retrospective cohort study of 108 surgical patients of empyema who encountered at our hospital between 2011 and 2021. Patients were divided into surviving and non-surviving cases. Factors on admission (age, sex, body mass index, presence of fistula, performance status, pleural fluid culture results, HbA1c, albumin, leukocytes, hemoglobin, body temperature, heart rate, respiratory rate, systolic blood pressure, prognostic nutritional index, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio and RAPID score) were compared between the two groups. RESULTS: There were 87 cases of pleural empyema caused by pneumonia due to common bacteria. Variables that differed significantly in univariate analysis between the surviving and non-surviving cases in patients' characteristics on admission were fistula (p value < 0.001, odds ratio 20.000, 95% confidence interval 3.478-115.022), positive pleural fluid culture (0.016, 6.591, 1.190-36.502), body mass index < 18.5 (0.001, 16.857, 1.915-148.349), performance status 0-1 (0.007, 11.778, 1.349-102.858), and hemoglobin (0.024, 1.768, 1.077-2.904). Multivariate analysis showed significant differences in the presence of fistula (p = 0.036, CI 1.174-125.825). The odds ratio was 12.154. The mortality rate was 3.8% for non-fistulous empyema and 44.4% for fistulous empyema. In 6 of 9 cases of fistulous empyema, the fistula could be closed. CONCLUSION: Fistula was a significant independent prognostic factor for pneumonia-associated pleural effusions and empyema caused by common bacteria.

Multi-omics of NET formation and correlations with CNDP1, PSPB, and L-cystine levels in severe and mild COVID-19 infections.

The detailed mechanisms of COVID-19 infection pathology remain poorly understood. To improve our understanding of SARS-CoV-2 pathology, we performed a multi-omics and correlative analysis of an immunologically naïve SARS-CoV-2 clinical cohort from blood plasma of uninfected controls, mild, and severe infections. Consistent with previous observations, severe patient populations showed an elevation of pulmonary surfactant levels. Intriguingly, mild patients showed a statistically significant elevation in the carnosine dipeptidase modifying enzyme (CNDP1). Mild and severe patient populations showed a strong elevation in the metabolite L-cystine (oxidized form of the amino acid cysteine) and enzymes with roles in glutathione metabolism. Neutrophil extracellular traps (NETs) were observed in both mild and severe populations, and NET formation was higher in severe vs. mild samples. Our correlative analysis suggests a potential protective role for CNDP1 in suppressing PSPB release from the pulmonary space whereas NET formation correlates with increased PSPB levels and disease severity. In our discussion we put forward a possible model where NET formation drives pulmonary occlusions and CNDP1 promotes antioxidation, pleiotropic immune responses, and vasodilation by accelerating histamine synthesis.

A Prospective Observational Study on the Tolerability of Transnasal Bronchoscopy With a Surgical Mask for Aerosol Control.

Background As far as we know, there are no reports comparing the safety and cough frequency of transnasal bronchoscopy (TNB) with transoral bronchoscopy (TOB). Methods The subjects were 50 patients who underwent either TNB or TOB and completed the pain score questionnaire between May and November 2020. Complications, pain scores, and cough frequency (times per minute) were compared between the patients with TNB and TOB. A surgical mask was worn over the mouthpiece during the examination. Results Thirty-two and 18 patients underwent TNB and TOB, respectively. Between the two groups, there were no significant differences in examination time and frequency of serious complications. In pain scores, there were no significant differences in terms of anesthesia suffering, several pains during the examination, and availability of re-examination. The TNB group did not feel the prolonged examination time compared to the TOB group (p=0.04). Cough frequency was lower in the TNB group than in the TOB group (0.36 vs 0.73, p=0.027). Moreover, cough frequency in the 25 TNB patients who underwent thin bronchoscopy was significantly lower (0.19 vs 0.73, p<0.01). Conclusions TNB with a surgical mask was well tolerated and safe. Cough frequency in the transnasal thin bronchoscopy was extremely low, suggesting aerosol reduction can be expected.

A Case of Asymptomatic Pulmonary Nocardia cyriacigeorgica Infection With Mild Diabetes Mellitus.

Nocardiosis is a relatively rare opportunistic infection, ranging from localized to systemic diseases, commonly occurring in immunocompromised patients with high mortality rates. We present a case of a 61-year-old man who received medical treatment for type 2 diabetes mellitus and underwent a physical examination that showed abnormal chest shadows on radiography. Chest computed tomography revealed bronchiectasis and infiltration in the left lower lobe. Nocardia spp. was detected in the bronchial washes, and he was started on sulfamethoxazole-trimethoprim under the diagnosis of pulmonary nocardiosis. 16S ribosomal RNA gene sequencing analysis identified the species as Nocardia cyriacigeorgica. His pulmonary lesions successfully improved after treatment for six months. Pulmonary nocardiosis often presents with symptoms such as hemoptysis and blood-tinged sputum, and bronchiectasis has been identified as an underlying condition. Even in hosts without underlying immunocompromising conditions, Nocardia spp. can be a causative microorganism of pulmonary infections, and it should be considered in the differential diagnoses.

Nafamostat Mesylate Monotherapy in Patients with Moderate COVID-19: a Single-Center, Retrospective Study.

Coronavirus disease (COVID-19) has spread dramatically worldwide. Nafamostat mesylate inhibits intracellular entry of the novel severe acute respiratory syndrome coronavirus 2 and is believed to have therapeutic potential for treating patients with COVID-19. In this study, patients with moderate COVID-19 who were admitted to our hospital were retrospectively analyzed. Thirty-one patients received monotherapy with nafamostat mesylate, and 33 patients were treated conservatively. Nafamostat mesylate was administered with continuous intravenous infusion for an average of 4.5 days. Compared with the conservative treatment, nafamostat mesylate did not improve outcomes or laboratory data 5 days after admission. In addition, no significant differences in laboratory data 5 days after admission and outcomes in high-risk patients were observed. The incidence of hyperkalemia was significantly higher in the nafamostat mesylate group; however, none of the patients required additional treatment. In conclusion, monotherapy with nafamostat mesylate did not improve clinical outcomes in patients with moderate COVID-19. This study did not examine the therapeutic potential of combining nafamostat mesylate with other antiviral agents, and further investigation is required. Because of the high incidence of hyperkalemia, regular laboratory monitoring is required during the use of nafamostat mesylate.

A case of pulmonary foreign body granuloma formation after transcatheter arterial chemoembolization for hepatocellular carcinoma.

We experienced a case of pulmonary foreign body granuloma diagnosed by bronchoscopy in a patient with multiple lung lesions after transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma. We speculate that the lesions may be caused by transarterial migration of the materials used for TACE.

Longitudinal Assessment of Prognostic Understanding in Patients with Advanced Lung Cancer and Its Association with Their Psychological Distress.

BACKGROUND: Accurate prognostic understanding in patients with advanced cancer is essential for shared decision making; however, patients may experience psychological burden through knowing the incurable nature of advanced cancer. It has been unclear how their prognostic understanding fluctuates and whether accurate prognostic understanding is associated with psychological distress from the time of diagnosis over time. MATERIALS AND METHODS: We longitudinally investigated prognostic understanding in 225 patients with newly diagnosed advanced lung cancer at 16 hospitals in Japan until 24 months after diagnosis. We examined associated factors with being consistently accurate in prognostic understanding, especially focusing on its association with psychological well-being. RESULTS: The proportion of patients with an inaccurate prognostic understanding remained approximately 20% over time with the presence of patients with inconsistent understanding. Patients with consistently accurate prognostic understanding showed a significantly lower Emotional Well-Being subscale score at both 3 and 6 months after diagnosis (p = .010 and p = .014, respectively). In multivariate analyses, being consistently accurate in prognostic understanding was significantly associated with female gender and higher lung cancer-specific symptom burden at 3 months (p = .008 and p = .005, respectively) and lower emotional well-being at 6 months (p = .006). CONCLUSION: Although substantial proportions of patients with advanced lung cancer had inaccurate prognostic understanding from the time of diagnosis over time, patients with consistently accurate prognostic understanding experienced greater psychological burden. Our findings highlight the importance of continuous psychological care and support for patients who understand their severe prognosis accurately. IMPLICATIONS FOR PRACTICE: This study demonstrated that approximately 20% of patients with advanced lung cancer had an inaccurate understanding about their prognosis, not only at the time of diagnosis but also at the later time points. Being consistently accurate in prognostic understanding was significantly associated with elevated levels of psychological distress. Although accurate prognostic understanding is essential for decision making for treatment and advance care planning, health care providers should be aware of psychological burdens in patients that accept their severe prognosis accurately. Appropriate care and support for such patients are warranted from diagnosis over time.

Omission of Throat Anesthesia Using Jackson's Spray Prior to Bronchoscopy for Preventing Aerosol Generation: A Survey Through Patient Distress Questionnaire.

Background and objective Due to the outbreak of coronavirus disease 2019 (COVID-19), the Japanese Society of Respiratory Endoscopy recommended the omission of throat anesthesia using Jackson's spray prior to bronchoscopy for preventing aerosol generation. In this survey, we investigated the tolerability of patients toward the omission of anesthesia using Jackson's spray before bronchoscopy. Methods Group A patients received throat anesthesia with 5 mL of 4% lidocaine using Jackson's spray prior to bronchoscopy and were then administered pethidine hydrochloride and midazolam intravenously. Group B patients did not receive anesthesia using Jackson's spray before bronchoscopy. They were administered pethidine hydrochloride and midazolam and were then administered 8% lidocaine several times into the pharynx. A patient distress questionnaire, classified as a five-graded score, was administered to each group after bronchoscopy. Results Seventy patients participated in this study: 39 patients in Group A and 31 patients in Group B. There were no significant differences in their backgrounds. In the questionnaire survey, the distress caused by pre-examination anesthesia in Group A was significantly higher than in Group B (3.03 ± 1.25 vs. 1.23 ± 0.62; p < 0.0001), and no significant differences were observed in the other questions during bronchoscopy. Conclusion This study demonstrates the tolerability of patients toward the omission of throat anesthesia using Jackson's spray prior to bronchoscopy, which is recommended for preventing infection, including COVID-19.

A Case of Guillain-Barré Syndrome and Stevens-Johnson Syndrome/Toxic Epidermal Necrosis Overlap After Pembrolizumab Treatment.

A 76-year-old man was admitted to our hospital with Guillain-Barré syndrome (GBS), presenting with facial palsy, dysarthria, and dysphagia as Grade 3 immune-related adverse events (irAEs) due to pembrolizumab administration for Stage IV lung adenocarcinoma. Although prednisolone (1 mg/kg) was started for GBS due to the irAE, dark erythema and skin eruptions appeared on the patient's torso. Then erosion was observed on 18% of the body surface area and skin biopsy was performed. Finally, the patient was diagnosed with Stevens-Johnson syndrome/toxic epidermal necrosis overlap. Intravenous immunoglobulin therapy was started, and the skin symptoms improved, with the erosion becoming epithelial. He died of aspiration pneumonia related to GBS, although his neurological symptoms had improved after steroid and intravenous immunoglobulin therapy. This is the first reported case of pembrolizumab-induced GBS and Stevens-Johnson syndrome/toxic epidermal necrosis overlap. It is necessary to be careful that the possibility of other severe irAEs may occur simultaneously.

Characterization of a new SARS-CoV-2 variant that emerged in Brazil.

The spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) plays a key role in viral infectivity. It is also the major antigen stimulating the host's protective immune response, specifically, the production of neutralizing antibodies. Recently, a new variant of SARS-CoV-2 possessing multiple mutations in the S protein, designated P.1, emerged in Brazil. Here, we characterized a P.1 variant isolated in Japan by using Syrian hamsters, a well-established small animal model for the study of SARS-CoV-2 disease (COVID-19). In hamsters, the variant showed replicative abilities and pathogenicity similar to those of early and contemporary strains (i.e., SARS-CoV-2 bearing aspartic acid [D] or glycine [G] at position 614 of the S protein). Sera and/or plasma from convalescent patients and BNT162b2 messenger RNA vaccinees showed comparable neutralization titers across the P.1 variant, S-614D, and S-614G strains. In contrast, the S-614D and S-614G strains were less well recognized than the P.1 variant by serum from a P.1-infected patient. Prior infection with S-614D or S-614G strains efficiently prevented the replication of the P.1 variant in the lower respiratory tract of hamsters upon reinfection. In addition, passive transfer of neutralizing antibodies to hamsters infected with the P.1 variant or the S-614G strain led to reduced virus replication in the lower respiratory tract. However, the effect was less pronounced against the P.1 variant than the S-614G strain. These findings suggest that the P.1 variant may be somewhat antigenically different from the early and contemporary strains of SARS-CoV-2.

Upregulation of FGF9 in Lung Adenocarcinoma Transdifferentiation to Small Cell Lung Cancer.

Transdifferentiation of lung adenocarcinoma to small cell lung cancer (SCLC) has been reported in a subset of lung cancer cases that bear EGFR mutations. Several studies have reported the prerequisite role of TP53 and RB1 alterations in transdifferentiation. However, the mechanism underlying transdifferentiation remains understudied, and definitive additional events, the third hit, for transdifferentiation have not yet been identified. In addition, no prospective experiments provide direct evidence for transdifferentiation. In this study, we show that FGF9 upregulation plays an essential role in transdifferentiation. An integrative omics analysis of paired tumor samples from a patient with transdifferentiated SCLC exhibited robust upregulation of FGF9. Furthermore, FGF9 upregulation was confirmed at the protein level in four of six (66.7%) paired samples. FGF9 induction transformed mouse lung adenocarcinoma-derived cells to SCLC-like tumors in vivo through cell autonomous activation of the FGFR pathway. In vivo treatment of transdifferentiated SCLC-like tumors with the pan-FGFR inhibitor AZD4547 inhibited growth. In addition, FGF9 induced neuroendocrine differentiation, a pathologic characteristic of SCLC, in established human lung adenocarcinoma cells. Thus, the findings provide direct evidence for FGF9-mediated SCLC transdifferentiation and propose the FGF9-FGFR axis as a therapeutic target for transdifferentiated SCLC. SIGNIFICANCE: This study demonstrates that FGF9 plays a role in the transdifferentiation of lung adenocarcinoma to small cell lung cancer.

A case of hyperprogressive disease following atezolizumab therapy for pulmonary pleomorphic carcinoma with epidermal growth factor receptor mutation.

A 66-year old man with non-smoking history was diagnosed with pulmonary pleomorphic carcinoma of the right lower lobe. The carcinoma metastasized to the brain, lungs, pleura, and mediastinal lymph nodes. It was positive for epidermal growth factor receptor (EGFR) L858R mutation, and tumor cells highly expressed programmed death-ligand 1(PD-L1). Atezolizumab was initiated as the fourth treatment. After three days, he developed cardiac tamponade and immediately underwent pericardial drainage. Computed tomography showed bilateral ground-glass opacity (GGO), significant worsening of multiple lung metastases, and increased size of metastatic lesions. Newly developed metastasis was noted in the lung, and the patient's respiratory condition rapidly deteriorated. He died of respiratory failure on day 13 after atezolizumab administration. The autopsy showed widespread metastasis in all lobes of the bilateral lungs, cardiac tamponade due to carcinomatous pericarditis, carcinomatous lymphangiopathy, and multiple lung metastases, which were thought to be comprehensively the cause of death. These symptoms suggested hyperprogressive disease (HPD). Hence, we report the first case of HPD following atezolizumab therapy for pulmonary pleomorphic carcinoma with EGFR mutation.

Homeless Patients with Lung Cancer in Metropolitan Tokyo.

Background Homeless persons are those who carry out their activities of daily living in city parks and other facilities. Little is known about homeless patients with lung cancer in Japan. Therefore, we characterized the clinical features and outcomes of homeless people in metropolitan Tokyo. Methods Between January 2014 and August 2018, 2,068 homeless patients were admitted to the homeless patient care unit at Tokyo Saiseikai Central Hospital. Of these, 13 patients were treated for primary lung cancer. We retrospectively analyzed the patients' clinical characteristics, including their age, gender, treatment, and outcome, obtained from the hospital's electronic medical records. Results A total of 13 patients were treated for lung cancer. The median age was 66.2 (range, 51-77) years old. Twelve patients (92.3%) were smokers. All of the patients were men and had advanced lung cancer. Of these, four patients had adenocarcinoma, four had squamous carcinoma, and four had other histologies. Ten patients received chemotherapy, and 3 received chemoradiotherapy (carboplatin, n=8; cisplatin, n=2, immune check point inhibitor, n=2; other, n=1). Of the patients on first-line treatment, 58% discontinued treatment, with 71% doing so willfully. The median overall survival was 7.5 (1-44) months. During the study, nine patients died in the hospital, and four were lost to follow up. Conclusion It is difficult for homeless patients to continue chemotherapy, and they often quit therapy willfully. Therefore, it is necessary to develop an education and health insurance support system to ensure treatment continuity in a good social environment.

Identification of B.1.346 Lineage of SARS-CoV-2 in Japan: Genomic Evidence of Re-entry of Clade 20C.

SARS-CoV-2 whole-genome sequencing of samples from COVID-19 patients is useful for informing infection control. Datasets of these genomes assembled from multiple hospitals can give critical clues to regional or national trends in infection. Herein, we report a lineage summary based on data collected from hospitals located in the Tokyo metropolitan area. We performed SARS-CoV-2 whole-genome sequencing of specimens from 198 patients with COVID-19 at 13 collaborating hospitals located in the Kanto region. Phylogenetic analysis and fingerprinting of the nucleotide substitutions were performed to differentiate and classify the viral lineages. More than 90% of the identified strains belonged to Clade 20B, which has been prevalent in European countries since March 2020. Only two lineages (B.1.1.284 and B.1.1.214) were found to be predominant in Japan. However, one sample from a COVID-19 patient admitted to a hospital in the Kanto region in November 2020 belonged to the B.1.346 lineage of Clade 20C, which has been prevalent in the western United States since November 2020. The patient had no history of overseas travel or any known contact with anyone who had travelled abroad. Consequently, the Clade 20C strain belonging to the B.1.346 lineage appeared likely to have been imported from the western United States to Japan across the strict quarantine barrier. B.1.1.284 and B.1.1.214 lineages were found to be predominant in the Kanto region, but a single case of the B.1.346 lineage of clade 20C, probably imported from the western United States, was also identified. These results illustrate that a decentralized network of hospitals offers significant advantages as a highly responsive system for monitoring regional molecular epidemiologic trends.

A phase II study of S-1 and cisplatin with concurrent thoracic radiotherapy followed by durvalumab for unresectable, locally advanced non-small-cell lung cancer in Japan (SAMURAI study).

BACKGROUND: Based on the results of the PACIFIC study, chemoradiotherapy followed by 1-year consolidation therapy with durvalumab was established as the standard of care for unresectable, locally advanced non-small-cell lung cancer (LA-NSCLC). However, some topics not foreseen in that design can be explored, including progression-free survival (PFS) and overall survival (OS) after the start of chemoradiotherapy, the proportion of patients who proceeded to consolidation therapy with durvalumab, and the optimal chemotherapeutic regimens. In Japan, the combination regimen of S-1 + cisplatin (SP), for which the results of multiple clinical studies have suggested a good balance of efficacy and tolerability, is frequently selected in clinical settings. However, the efficacy and safety of consolidation therapy with durvalumab following this SP regimen have not been evaluated. We therefore planned a multicenter, prospective, single-arm, phase II study. METHODS: In treatment-naïve LA-NSCLC, two cycles of combination chemotherapy with S-1 (80-120 mg/body, Days 1-14) + cisplatin (60 mg/m2, Day 1) will be administered at an interval of 4 weeks, with concurrent thoracic radiotherapy (60 Gy). Responders will then receive durvalumab every 2 weeks for up to 1 year. The primary endpoint is 1-year PFS rate. DISCUSSION: Compared with the conventional standard regimen in Japan, the SP regimen is expected to be associated with lower incidences of pneumonitis, esophagitis, and febrile neutropenia, which complicate the initiation of consolidation therapy with durvalumab, and have higher antitumor efficacy during chemoradiotherapy. Therefore, SP-based chemoradiotherapy is expected to be successfully followed by consolidation therapy with durvalumab in more patients, resulting in prolonged PFS and OS. Toxicity and efficacy results of the SP regimen in this study will also provide information important to the future establishment of the concurrent combination of chemoradiotherapy and durvalumab. TRIAL REGISTRATION: Japan Registry of Clinical Trials, jRCTs031190127, registered 1 November 2019, https://jrct.niph.go.jp/latest-detail/jRCTs031190127.

Trends of concerns from diagnosis in patients with advanced lung cancer and their family caregivers: A 2-year longitudinal study.

BACKGROUND: Both advanced cancer patients and their family caregivers experience distress and have a range of concerns after cancer diagnosis. However, longitudinal studies on this topic have been lacking. AIM: To investigate concerns in both patients with advanced lung cancer and their family caregivers longitudinally from diagnosis. DESIGN: A multi-center prospective questionnaire-based study. SETTING/PARTICIPANTS: We recruited patients with newly diagnosed advanced lung cancer and their family caregivers at 16 hospitals in Japan. We prospectively assessed the prevalence of their concerns using the Concerns Checklist and investigated the associations between their concerns and mental status as well as quality of life until 24 months after diagnosis. RESULTS: A total of 248 patients and their 232 family caregivers were enrolled. The prevalence of serious concerns was highest at diagnosis (patients: 68.3%, family caregivers: 65.3%). The most common serious concern was concern about the future in both groups at diagnosis (38.2% and 40.5%, respectively) and this remained high in prevalence over time, while the high prevalence of concern about lack of information improved 3 months after diagnosis in both groups. Approximately one-third of patient-family caregiver dyads had discrepant reports of serious concerns. The presence of serious concerns was significantly associated with anxiety and depression continuously in both groups. CONCLUSIONS: The majority of advanced lung cancer patients and their family caregivers have serious concerns from diagnosis, which is associated with their psychological distress. The spectrum of concerns alters over the disease trajectory, warranting efficient tailored care and support for both groups immediately after diagnosis.

A Case of Intravascular Diffuse Large B-Cell Lymphoma Initially Suspected as Interstitial Pneumonia Associated With Systemic Scleroderma.

Intravascular large B-cell lymphoma (IVLBCL) is a rare form of diffuse LBCL. The patient was a 71-year-old female admitted to our hospital with hypoxia. On admission, chest computed tomography revealed a ground-glass opacity. Interstitial pneumonia associated with systemic scleroderma was suspected because of positive anti-centromere antibody. Thereafter, steroid pulse therapy and plasma exchange were performed. Although ground-glass opacity improved, bilateral pleural effusion appeared, so we performed a random skin biopsy because of her elevated serum lactate dehydrogenase and soluble interleukin-2 receptor levels. The patient was diagnosed with IVLBCL with symptoms improving after 6 cycles of rituximab plus chemotherapy treatment.

Chest wall fistula in a patient with pyothorax-associated lymphoma.

Fistula formation is an uncommon but serious therapeutic complication of pyothorax-associated lymphoma (PAL) because it decreases the quality of life in patients. Furthermore, a collapsed lung may predispose to pneumonia. In PAL, the lesions might invade the skin and optimal irradiation dose, region, and timing should be carefully determined.

Antibody titers against SARS-CoV-2 decline, but do not disappear for several months.

BACKGROUND: To develop an effective vaccine against a novel viral pathogen, it is important to understand the longitudinal antibody responses against its first infection. Here we performed a longitudinal study of antibody responses against SARS-CoV-2 in symptomatic patients. METHODS: Sequential blood samples were collected from 39 individuals at various timepoints between 0 and 154 days after onset. IgG or IgM titers to the receptor binding domain (RBD) of the S protein, the ectodomain of the S protein, and the N protein were determined by using an ELISA. Neutralizing antibody titers were measured by using a plaque reduction assay. FINDINGS: The IgG titers to the RBD of the S protein, the ectodomain of the S protein, and the N protein peaked at about 20 days after onset, gradually decreased thereafter, and were maintained for several months after onset. Extrapolation modeling analysis suggested that the IgG antibodies were maintained for this amount of time because the rate of reduction slowed after 30 days post-onset. IgM titers to the RBD decreased rapidly and disappeared in some individuals after 90 days post-onset. All patients, except one, possessed neutralizing antibodies against authentic SARS-CoV-2, which they retained at 90 days after onset. The highest antibody titers in patients with severe infections were higher than those in patients with mild or moderate infections, but the decrease in antibody titer in the severe infection cohort was more remarkable than that in the mild or moderate infection cohort. INTERPRETATION: Although the number of patients is limited, our results show that the antibody response against the first SARS-CoV-2 infection in symptomatic patients is typical of that observed in an acute viral infection. FUNDING: The Japan Agency for Medical Research and Development and the National Institutes of Allergy and Infectious Diseases.