Representative species of Campylobacter include Campylobacter jejuni, Campylobacter coli, and Campylobacter fetus. We experience a case that it has been detected C. fetus from culture of diarrhea stool at 42°C in a microaerobic condition. So, to investigate the identification of Campylobacter spp., we performed PCR as golden standard, growth tests at 25°C and 42°C, hippurate hydrolysis tests, and indoxyl acetate hydrolysis tests using 66 strains of Campylobacter spp. In the growth tests, all strains grew at 42°C, and only 6 strains of C. fetus grew at 25°C. The hippurate hydrolysis test was performed at the observation time of 15 minutes (manufacture’s insertion) and 60 minutes, and the sensitivity was 55.6% (20/36) and 88.9% (32/36), respectively. And there were no false positives when the test was extended to 60 minutes. There were no false positives in the indoxyl acetate hydrolysis test, and the sensitivity was 98.3% (59/60). The agreement rate between the PCR method and the biochemical property tests (using observation time 60 min for the hippurate hydrolysis test) was 93.9% (62/66). For the identification of Campylobacter spp., it was shown that many Campylobacter fetus subsp. fetus can grow at 42°C, that the observation time of the hippuric acid hydrolysis test needs to be extended up to at least 60 min, and that the indoxyl acetate hydrolysis test is a useful auxiliary test.

This study aimed to evaluate whether the abnormal distribution of the nuclear lamina caused by human papillomavirus (HPV) infection contributes to nuclear morphological abnormalities in low-grade squamous intraepithelial lesion (LSIL) diagnosis. Immunochemical analysis of the nuclear lamina was conducted on 20 cases diagnosed with LSIL via endocervical cytology and CIN1 through histological examination. The assessment focused on (1) the prevalence of seven atypical cellular morphologies (nuclear wrinkles/grooves, irregular nuclear contours, nuclear three-dimensional irregularity, multinucleation, coarse chromatin, smudged chromatin, and koilocytosis) and (2) the presence or absence of the nuclear membrane line in immunocytochemistry (ICC) and immunohistochemistry (IHC) using lamin A/C antibodies. The observed frequencies of cellular morphological abnormalities were as follows: nuclear wrinkles/grooves (18.0%), irregular nuclear contours (4.2%), nuclear three-dimensional irregularity (28.4%), multinucleation (12.8%), coarse chromatin (84.9%), smudged chromatin (7.3%), and koilocytosis (42.3%). Nuclear three-dimensional irregularity was significantly more frequent than irregular nuclear contours, multinucleation, and smudged chromatin. Regarding lamin A/C staining, the absence of the nuclear membrane line was observed more frequently than its presence in both ICC (84.8% vs. 15.2%) and IHC (85.3% vs. 14.7%). In conclusion, these findings suggest that nuclear three-dimensional irregularity could serve as a new diagnostic criterion for LSIL. Additionally, the study confirms that HPV infection contributes to the abnormal distribution of the nuclear lamina, potentially leading to various nuclear morphological abnormalities.

5q-spinal muscular atrophy (5q-SMA) is an autosomal recessive neuromuscular disease that is caused in most patients (95%) by homozygous deletion of SMN1 gene. In the remaining patients (5%), it is caused by heterozygous SMN1 gene deletion with intragenic mutations in the other copy. We have been performing genetic analyses of 5q-SMA since 2021 at Kobe University Hospital. In this study, we performed DNA sequence analysis of 14 patients suspected of having 5q-SMA retaining SMN1 gene. Our analyses identified a frameshift mutation (c.691dup) in one patient, SMN1/SMN2 hybrid genes in two patients, and c.462A>G (synonymous) in all patients. Due to the very high frequency of c.462A>G in our patients, we reevaluated its pathogenicity described as “Likely benign” in the Clinvar. Our mRNA and in silico analyses indicate that c.462A>G did not affect the SMN1 splicing pattern. We conclude that c.462A>G is not pathogenic and is not associated with the development of 5q-SMA. Pursuant to our investigations, we found that reference database contained sequences from a small number of populations and that the database lacked gene sequence information from healthy individuals because of a homologous gene, which may make it difficult to evaluate variant pathogenicity. When evaluating variant pathogenicity, it is necessary to consider gene characteristics including the presence of a homologous gene and the quality of the database.

Automated insulin delivery (AID) therapy is a treatment in which an insulin pump is linked to real-time continuous glucose monitoring (CGM) to automatically infuse insulin. In recent years, insulin pumps equipped with hybrid closed loop (HCL) technology, which allows automatic basal insulin adjustment, and advanced hybrid closed loop (AHCL) technology, which allows automatic bolus insulin delivery, have been approved. Automated insulin delivery (AID) therapy is expected to achieve better glycemic control than SAP therapy, but there are few reports on its utility in Japan. In this study, we analyzed the glycemic variability before and after the introduction of AID therapy in 22 patients with type 1 diabetes (8 males, 14 females; mean age 49.8 ± 18.9 years) who visited our hospital between January 2022 and June 2024 and used the MiniMed 770G or 780G insulin pump systems. Glucose management indicator (GMI) for AID (HCL/AHCL) therapy was 7.0% and 6.8~7.0%, respectively time in range (TIR) was 69.2~70.4% and 70.7~72.8%, time above range (TAR) was 26.8~28.9% and 24.6~26.7%, time below range (TBR) was 1.9~3.0% and 2.5~2.6%, meeting the target values for glycemic control recommended by CGM guidelines. These results demonstrated that AID therapy is a highly effective and safe treatment that can correct hyperglycemia without increasing hypoglycemic events compared to SAP therapy. Automated insulin delivery (AID) therapy is a treatment in which an insulin pump is linked to real-time continuous glucose monitoring (CGM) to automatically infuse insulin.

Antiphospholipid syndrome (APS) is an autoimmune disorder characterized by the presence of antiphospholipid antibody (aPL), which is autoantibody targeting phospholipid-related proteins in the blood. This condition leads to complications such as arterial and venous thrombosis and recurrent pregnancy loss. In Japan, approximately half of APS cases are secondary APS associated with autoimmune diseases, the most common being systemic lupus erythematosus (SLE). APS in conjunction with SLE (SLE/APS) is known to cause severe and diverse thrombotic events, though the underlying pathophysiological mechanisms remain unclear. Recent studies have suggested that excessive formation of neutrophil extracellular traps (NETs) is a major mechanism contributing to thrombosis in APS and SLE/APS. This study aimed to elucidate the impact of aPL on NETs formation. Human peripheral blood granulocytes were stimulated with serum from SLE/APS patients and aPL IgG to examine whether NET formation is induced. The results indicated that aPL could potentially induce an increase in the proportion of SYTOX^® Green-positive cells, neutrophil elastase activity in culture supernatants, and the proportion of reactive oxygen species (ROS)-producing cells within granulocytes. These findings suggest that aPL-induced cell death is associated with NETs formation. Furthermore, they imply that in the blood of APS patients, aPL may promote thrombosis through NETs.

Knowing the status of herd immunity in a community to a specific infectious disease is important for forecasting the future course of the disease epidemic in that community. In this study, we conducted a survey to investigate the acquisition of antibodies against the nucleocapsid (N) protein antigen of SARS-CoV-2 among hospital employees, aiming to understand the past prevalence of the disease among them. The results revealed that, as of June 2024, approximately 70% of the employees had been infected with SARS-CoV-2. Furthermore, the subclinical infection rate of the disease was also investigated by combining a questionnaire survey of the employees with records from the hospital’s mandatory reporting system for employees who had been diagnosed with COVID-19. Consequently, it was revealed that 71.7% of the staff had anti-N antibodies, and 30% of them had subclinical infections. Notably, 7.5% of the staff did not seek medical attention despite experiencing some symptoms of the disease. These facts underscore the need for specific measures to enable staff members to undergo testing easily to be implemented for infection control in the hospital. Virologically, there was no statistically significant difference in the levels of anti-N antibodies acquired by overt and subclinical infections, and there was no difference in the rate of these infections according to the frequency of the vaccination, suggesting that there is no need to distinguish between overt and subclinical infections, at least in terms of anti-N antibodies.

This study evaluates the sensitivity enhancement of Q-line Kyokuto^® PBP2’ using our proprietary pre-treatment method on blood culture-positive bottles. A total of 150 samples with positive blood cultures and direct identification of Staphylococcus spp. by VITEK MS were examined. Q-line Kyokuto^® PBP2’ was performed according to the package insert using the standard method with colonies from subcultured blood culture-positive bottles as samples. We compared this method, referred to as “Q Direct Method,” with our developed method using samples pretreated with Sputazyme, known as “Our Method.” Of the 150 samples, 84 were Staphylococcus aureus strains (48 methicillin-sensitive [MSSA] and 36 methicillin-resistant [MRSA]), and 66 were coagulase-negative staphylococci (CNS) strains (30 methicillin sensitive [MSCNS] and 36 methicillin-resistant [MRCNS]). For S. aureus, the Q Direct Method exhibited 97.2% sensitivity, 100% specificity, 98.8% reproducibility, and a 0.98 kappa statistic. In contrast, Our Method showed 100%, 100%, 100%, and 1 for each parameter. Concerning CNS, the Q Direct Method displayed 52.8% sensitivity, 100% specificity, 74.2% reproducibility, and a 0.50 kappa statistic. Our Method yielded 94.4%, 100%, 97.0%, and 0.94 for the respective parameters. Our findings suggest that our method of pretreating blood culture samples enables the rapid detection of PBP2’ from both S. aureus and CNS with a level of reproducibility comparable to the standard method.

Soluble interleukin-2 receptor (sIL-2R) is significantly elevated in patients with non-Hodgkin lymphoma and adult T-cell leukemia/lymphoma (ATL), making it an outstanding serum biomarker of these diseases. While chemiluminescent enzyme immunoassay (CLEIA), enzyme-linked immunosorbent assay (ELISA), and latex turbidimetric immunoassay (LTIA) are routine assays for sIL-2R, non-specific reactions are reportedly more common in LTIA than in CLEIA and ELISA. In the present study, we evaluated (N-type) Nanopia IL-2R—a recently-marketed improved LTIA reagent developed by SEKISUI MEDICAL CO., LTD. to inhibit non-specific reactions—in order to determine its basic performance and its inhibitory effect on non-specific reactions. For the control reagents, we used the conventional LTIA reagent and a CLEIA reagent. The results showed that the improved LTIA reagent had satisfactory basic performance, and that the correlation between serum sIL-2R values determined by CLEIA and those determined by LTIA was higher for the improved LTIA reagent than for the conventional LTIA reagent. In the immunoglobulin absorption test using samples from discrepant cases, the improved LTIA reagent demonstrated a suppressive effect on non-specific reactions mainly caused by IgG. The results of the present study demonstrated that the improved reagent performs sufficiently when used in routine LTIA of serum sIL-2R values. The results also suggest that compared to the conventional LTIA reagent, the improved LTIA reagent strongly inhibits non-specific reactions with immunoglobulin—particularly IgG—in serum samples.

Methotrexate is used for hematopoietic malignancies and rheumatoid arthritis. Its mechanism of action involves suppress the activity of dihydrofolate reductase which is essential for nucleic acid synthesis, and leading to the depletion of reduced folic acid and thereby preventing the proliferation of tumor cells. In high dose methotrexate therapy for the treatment of central nervous system invasion of malignant lymphoma or osteosarcoma, it is essential to measure the blood concentration at 24, 48, and 72 hours after the initiation of administration. Recently, a reagent called “Lumipulse Presto Methotrexate” (Fujirebio Inc) has been developed for measurement with the Lumipulse L2400 (Fujirebio Inc), and a preliminary study was conducted in preparation for the introduction of the reagent. Good results were observed for within-run precision, between-day precision, dilution linearity, detection limit, and quantification limit, while no effects of coexisting substances or storage conditions were observed. The correlation coefficients with our conventional reagent, “ARCHITECT Methotrexate” (Abbott Japan LLC) and serum samples were high at 0.993 and 0.999, the regression equations were y = 1.139x − 0.019 and y = 1.014x − 0.004, and no deviated sample was observed. In conclusion, it was suggested that the introduction of the reagent is feasible because of its good performance. The major feature of the reagent is its broader measurement range compare to the conventional reagent, which is expected to reduce the retest rate and the turnaround time required, and contribute to clinical practice.

Antifungal susceptibility testing of Candida spp. in Japan is compliant with the Clinical and Laboratory Standards Institute (CLSI). The latest CLSI documents are M27 Fourth Edition and M27M44S-Ed3 (Ed4/M44S-Ed3), while most domestic kits use the old documents M27-A3 and M27-S3 (A3/S3). The main differences between the old and new documents are the determination time and the criteria, and there is a possibility that the measurement results may deviate significantly depending on the edition. In this study, two standard strains and 92 clinical isolates of Candida spp. were tested using ASTY (Kyokuto Seiyaku Kogyo), and the results were evaluated when measured according to A3/S3 and the latest Ed4/M44S-Ed3 as per the attached document. The MIC values were calculated according to both standards, and the accuracy evaluation and the MIC value agreement and sensitivity rates were examined. The MIC values of the standard strains were within the precision control range for both standards. The overall MIC concordance rate was 92.6% within a two-well difference. Discordant was observed in Candida albicans, Candida glabrata, Candida tropicalis, and Candida krusei in 33 isolates (CPFG: 24, FLCZ: 8, VRCZ: 1). Comparison of the M44S-Ed3 showed VME: 4 strains (CPFG: 2 strains of C. glabrata and CPFG: 2 strains of C. krusei.), mE: 29 strains. This study has clarified the trends and effects of the new and the old documents. In the future, clinical evaluation using MIC values based on the latest standards should be validated with a sufficient number of strains, including drug-resistant strains.

In Staphylococcus aureus bacteremia (SAB), prompt identification of methicillin-resistant Staphylococcus aureus (MRSA) or methicillin-susceptible Staphylococcus aureus (MSSA) using molecular assays facilitates appropriate antimicrobial treatment. In November 2020, our hospital introduced the Xpert MRSA/SA Blood Culture “Cepheid” (GX), a reagent designed for the GeneXpert system (Beckman Coulter), an automated genetic analyzer. This system enables the identification of methicillin resistance status upon positive blood culture results. In this retrospective study, we divided SAB cases at our hospital into periods before and after GX introduction and evaluated the utility of GX. Following the introduction of GX, cefazolin (CEZ) usage increased, and anti-MRSA drug usage decreased in MSSA cases on positive reporting days. In contrast, CEZ usage decreased, and anti-MRSA drug administration increased for MRSA cases during the same period. Although 30-day mortality rates remained unchanged, the time to fever resolution (37.0°C) decreased, resulting in shorter hospital stays. These findings suggest that the introduction of GX optimized antimicrobial usage by reducing anti-MRSA drug administration in MSSA cases and enabling early administration in MRSA cases, thereby reducing drug costs and contributing to earlier improvement of clinical outcomes.

Background: The cefazolin inoculum effect (CzIE), in which the minimum inhibitory concentration (MIC) of cefazolin increases depending on the bacterial inoculum, has been reported to affect the prognosis of infections caused by methicillin-susceptible Staphylococcus aureus (MSSA). However, evaluating CzIE using high inocula (HI) for all isolates is impractical in clinical settings. This study aimed to evaluate whether routine microbiological tests could help screen for CzIE in MSSA isolates. Methods: We analyzed 179 MSSA isolates detected from blood cultures at Chutoen General Medical Center between May 2013 and January 2023. CzIE was defined as a cefazolin MIC ≤ 8 μg/mL with standard inocula (SI) and ≥ 16 μg/mL with HI. Results: CzIE was observed in 9 isolates (5.0%). The frequency of CzIE was 0.0% (0/128) in isolates with SI MIC ≤ 0.5 μg/mL, 14.6% (7/48) with MIC = 1 μg/mL, and 66.7% (2/3) with MIC = 2 μg/mL. No CzIE was observed in β-lactamase-negative isolates. By excluding MSSA isolates with SI MIC ≤ 0.5 μg/mL or negative β-lactamase results, 128 isolates (72%) could be omitted from HI testing. Conclusion: The proposed exclusion criteria enabled efficient CzIE screening by reducing the number of additional tests without missing any CzIE-positive strains. Routine microbiological tests may serve as useful tools for evaluating CzIE in MSSA in clinical laboratories.

This study aimed to elucidate the current status of microscopic examinations for ova and parasites (O&P) performed by medical technologists in Japan, as well as to assess their perceptions of molecular diagnostics. An online survey was conducted from January 30 to March 8, 2025. A total of 137 individuals participated, of whom 65 had experience with O&P examinations. Approximately 88% reported performing O&P examinations once a month or less, and nearly half indicated a similar frequency on an annual basis, highlighting a notable lack of practical experience. Furthermore, about 90% of the respondents reported that the positivity rate was either “almost none” or “none at all,” and the range of parasite species they had encountered was limited. Meanwhile, although molecular diagnostics are expected to complement morphological identification in challenging cases, evaluations of test performance and cost-effectiveness were regarded as important. Additionally, the data showed that a low number of test requests and the lack of a structured mentorship system—both seemingly influenced by years of experience—hampered skill acquisition. In light of the declining use of O&P examinations and the limited adoption of molecular diagnostics, this study underscores the need to enhance educational and training programs and to integrate both techniques in a complementary manner. These findings may serve as a foundation for future improvements in parasite diagnostic systems.

KL-6 is a high-molecular-weight glycoprotein derived from MUC1, produced by type II alveolar epithelial cells and mesothelial cells. It is utilized as an indicator of disease activity and prognosis in interstitial pneumonia. While its utility as a tumor marker has also been reported, its specificity is limited as its levels can be elevated in non-tumor diseases. This study aimed to assess the diagnostic utility of measuring KL-6 (PE-KL6) and CEA (PE-CEA) in pleural effusion to assist in the diagnosis of malignant pleural effusion. The study included 57 pleural effusion samples, categorized into benign (35 cases), adenocarcinoma (14 cases), malignant mesothelioma (4 cases), among others. PE-KL6 levels were significantly elevated in adenocarcinoma, with an area under the curve (AUC) of 0.941 for adenocarcinoma and 0.981 for adenocarcinoma + malignant mesothelioma. PE-CEA, on the other hand, was more specific to adenocarcinoma but showed low sensitivity for malignant mesothelioma. The results indicated that a combination of both markers may improve diagnostic accuracy. PE-KL6 proved particularly useful for diagnosing malignant mesothelioma, while PE-CEA was more specific to adenocarcinoma. The combination of these markers could be helpful in distinguishing between adenocarcinoma and malignant mesothelioma, offering improved diagnostic capabilities in clinical settings. Further studies with a larger number of cases are necessary to confirm these findings and refine the diagnostic approach for malignant pleural effusion.

Creutzfeldt-Jakob disease (CJD) is a fatal disorder caused by the accumulation of abnormal prion proteins in the central nervous system, leading to death from systemic weakness, respiratory failure, pneumonia, and other complications. Due to the lack of effective treatments, EEG examinations are rarely conducted after diagnosis. We report the EEG findings of a patient with CJD who was able to be followed up over a long period. The patient presented with rapidly progressing memory impairment, left homonymous hemianopia, and gait disturbance over a short period and visited our hospital. MRI diffusion-weighted imaging of the head showed extensive high-signal areas, and EEG examination revealed generalized periodic discharges (GPDs). GPDs appeared predominantly in the occipital region at approximately 1-second intervals. Over time, GPDs expanded from the occipital region to the occipital-parietal region and eventually became widespread, reaching their highest amplitude about three months after onset. It has been reported that GPDs disappear, and the EEG flattens in the terminal stage of CJD, but in this case, GPDs were still observed 2 years and 6 months after onset, albeit with reduced amplitude and frequency.

We encountered two cases of strongly suspected hemoglobin variants based on an abnormal result message from a device using the HPLC method for measuring HbA1c. HbA1c was measured primarily for screening before a main examination or a physical examination of patients. In our hospital, the incidence of instrumental abnormal messages was 0.1% to 0.2% (30 to 50 samples/year, including patients with multiple samples). The majority of these messages were “HbA0: Abnormally low value” and “HbF: Abnormally high value,” with three to five abnormal messages potentially indicative of hemoglobin variant(s) per year, including “L-A1c: Abnormally high value,” “Duplex peaks,” and “S-A1c tail.” Some hemoglobin variants have an abnormal oxygen affinity, resulting in hemolytic disease, polycythemia, or cyanosis. On the other hand, some hemoglobin variant carriers are asymptomatic with no hematological abnormalities. When an abnormal message from an analyzer is detected, it is important to determine the cause and if necessary, inform the relevant clinician that the hemoglobin variant may affect HbA1c values, and explain other test parameters, such as glycoalbumin, that can be used as a measure of glycemic control. Now that the number of foreign workers is increasing and people of various races live in Japan due to a variety of events, detection and reporting of hemoglobin variants will be something that we need more than ever.

The cross mixing test (CMT) is used to investigate the cause of prolonged activated partial thromboplastin time (APTT). In the present study, we experienced a case of lupus anticoagulant (LA)-positive mild hemophilia A in which the immediate response of CMT showed an approximate baseline pattern and the delayed response showed a convex downward pattern. The patient, a man in his 70s, underwent surgery before and after surgery for an abdominal aortic aneurysm with pegylated recombinant factor VIII blood coagulation (Adinovate). Both immediate and delayed responses of CMT on the day after adinovate administration showed a baseline approximation pattern. On the other hand, Factor VIII activity before adinovate administration was low (< 0.4%) due to heating. This markedly prolonged the clotting time of 100% patient plasma, which may have resulted in a different pattern from the immediate response. For the interpretation of CMT in samples with both low coagulation factors and LA, it was important to focus on the difference between immediate and delayed reactions in 100% patient plasma. In addition, the numerical judgment method was considered to contribute to the performance characteristics of the indicators used, since the judgment results were inhibitory for all indicators before and after adinovate administration. Therefore, when the waveform pattern of the CMT is unclear or when the results of the visual and numerical judgment methods differ, additional tests should be performed to differentiate between them.

We reported cases of false low values in the enzymatic calcium assay using phospholipase D. There was no abnormality in the reaction time-course, but dilution reproducibility was not obtained. Therefore, we conducted the following study to investigate this issue. The patients had biliary stasis and high levels of phospholipids and free cholesterol. Lipoprotein X (Lp-X) presence was suggested by a confirmation test using the precipitation method. Based on the reagent principle, we suspected a non-specific reaction caused by phospholipids, which are abundant in Lp-X. To test this, lecithin was added to pooled serum or purified water as a source of phospholipids and the reaction were observed. Phospholipase D acted not only on the chromogenic substrates but also on the phospholipids. In the phospholipid coexistence effect test, calcium measurements were decreased in a phospholipid concentration dependent. These results suggest that high concentrations of phospholipids cause false low calcium values in the phospholipase D enzymatic assay due to competition with chromogenic substrates.