Age and sex differences in the risk of cardiovascular diseases by chronic kidney disease in a general Japanese population.

The risk of cardiovascular diseases (CVD) by chronic kidney disease (CKD) stratified by age and sex has not been examined in detail in rural Japanese populations. Therefore, we herein investigated the long-term risk of CVD by CKD and performed an age- and sex-stratified risk analysis. We examined 5163 subjects who underwent health screening between 1992 and 1995 with calculated eGFR and follow-up information on CVD events. The mean follow-up period was 10 years. We analyzed the incidences of CVD events, including stroke and myocardial infarction (MI). We compared the risk of CVD between subjects with and without CKD using a Cox proportional hazards model adjusted for well-known CVD confounding factors. The total number of CVD events was 175. The hazard ratios (HRs) for all events, stroke, MI, and sudden death by CKD relative to non-CKD were 1.18 (95% C.I.:0.83-1.68), 0.96 (0.63-1.46), 3.02 (1.2-7.62), and 1.29 (0.43-3.87), respectively. HRs for MI were 7.24 in subjects < 65 years and 1.65 in those ≥ 65 years. HRs for MI by sex were 3.55 in men and 2.09 in women. A younger age and men sex were identified as independent risk factors for the risk of MI in the presence of CKD. These results suggest that among CKD patients, the management of a younger age group and men will effectively prevent MI.

Disseminated Mycolicibacter arupensis and Mycobacterium avium co-infection in a patient with anti-interferon-γ neutralizing autoantibody-associated immunodeficiency syndrome.

BACKGROUND: Disseminated infections of Mycolicibacter arupensis, a slowly growing nontuberculous mycobacteria (NTM) which causes synovitis, osteomyelitis, or pulmonary infections have rarely been reported. We report a case of disseminated M. arupensis and Mycobacterium avium co-infection in a patient with anti-interferon (IFN)-γ neutralizing autoantibody-associated immunodeficiency syndrome. CASE PRESENTATION: A 68-year-old Japanese male without human immunodeficiency virus infection was referred with complaints of persistent low-grade fever, arthralgia of the upper limbs, and weight loss of 10 kg. Cervical and mediastinal lymphadenopathies as well as a nodular opacity in the right lung were detected, and biopsy specimens of the cervical lymph node yielded M. arupensis without evidence of malignant cells. M. arupensis was also detected in sputum and peripheral blood. Computed tomography (CT) revealed deterioration of the right supraclavicular lymphadenopathy with internal necrosis and multiple low-density splenic lesions. Bone marrow and aspirates from the cervical lymph node collected at initiation of treatment yielded M. avium. The presence of anti-IFN-γ neutralizing autoantibodies was detected, leading to a diagnosis of co-infection of M. arupensis and M. avium with anti-IFN-γ neutralizing autoantibody-associated immunodeficiency syndrome. Post initiation of treatment with clarithromycin, ethambutol, and rifabutin, his fever declined, and his polyarthritis resolved. He developed disseminated varicella zoster during treatment; however, a follow-up CT scan six months after treatment revealed improvement of the lymphadenopathies, consolidation in the right lung, and splenic lesions. CONCLUSION: This is the first report of disseminated M. arupensis and M. avium co-infection in a patient with anti-IFN-γ neutralizing autoantibody-associated immunodeficiency syndrome.

Epidemiology and Risk Factors for Giant Coronary Artery Aneurysms Identified After Acute Kawasaki Disease.

A giant coronary artery (CA) aneurysm is a potentially fatal cardiac complication resulting from Kawasaki disease (KD). We aimed to identify epidemiologic characteristics and potential risk factors associated with giant CA aneurysms identified after acute KD. We analyzed 90,252 patients diagnosed with KD from 2011 to 2018, using data obtained in nationwide KD surveys conducted in Japan. Multivariable logistic regression analyses were performed to evaluate potential risk factors associated with subsequent giant CA aneurysm complications (defined as lumen size ≥ 8 mm), adjusting for all potential factors. Giant CA aneurysms were identified in 144 patients (0.16%) after acute KD. The annual prevalence ranged from 0.07 to 0.20% during the study period. In the multivariate analyses, male sex (adjusted odds ratio 2.09 [95% confidence interval 1.41-3.11], recurrent KD (1.90 [1.09-3.33]), IVIG administration at 1-4 days of illness (1.49 [1.04-2.15]) and ≥ 8 days after KD onset (2.52 [1.38-4.60]; reference, 5-7 days), detection of CA dilatations and aneurysms at initial echocardiography (4.17 [1.85-5.41] and 46.5 [28.8-74.8], respectively), and resistance to IVIG treatment (6.09 [4.23-8.75]) were significantly associated with giant CA aneurysm complications identified after acute KD. The annual prevalence of giant CA aneurysms identified after acute KD did not increase during the study period. Patients with larger CA abnormalities detected at initial echocardiography were independently associated with progression to giant CA aneurysm complications after acute KD regardless of the number of days from onset at treatment initiation.

Limited effects from professional identity formation-oriented intervention on self-regulated learning in a preclinical setting: a randomized-controlled study in Japan.

BACKGROUND: Developing self-regulated learning in preclinical settings is important for future lifelong learning. Previous studies indicate professional identity formation, i.e., formation of self-identity with internalized values and norms of professionalism, might promote self-regulated learning. We designed a professional identity formation-oriented reflection and learning plan format, then tested effectiveness on raising self-regulated learning in a preclinical year curriculum. METHODS: A randomized controlled crossover trial was conducted using 112 students at Jichi Medical University. In six one-day problem-based learning sessions in a 7-month pre-clinical year curriculum, Groups A (n = 56, female 18, mean age 21.5y ± 0.7) and B (n = 56, female 11, mean age 21.7y ± 1.0) experienced professional identity formation-oriented format: Group A had three sessions with the intervention format in the first half, B in the second half. Between-group identity stages and self-regulated learning levels were compared using professional identity essays and the Motivated Strategies for Learning Questionnaire. RESULTS: Two-level regression analyses showed no improvement in questionnaire categories but moderate improvement of professional identity stages over time (R2 = 0.069), regardless of timing of intervention. CONCLUSIONS: Professional identity moderately forms during the pre-clinical year curriculum. However, neither identity nor self-regulated learning is raised significantly by limited intervention.

Using text mining to analyze reflective essays from Japanese medical students after rural community placement.

BACKGROUND: Following community clinical placements, medical students use reflective writing to discover the story of their journey to becoming medical professionals. However, because of assessor bias analyzing these writings qualitatively to generalize learner experiences may be problematic. This study uses a process-oriented text mining approach to better understand meanings of learner experiences by connecting key concepts in extended student reflective essays. METHODS: Text mining quantitative analysis is used on self-evaluative essays (n = 47, unique word count range 43-575) by fifth-year students at a regional quota-system university in Japan that specializes in training general practitioners for underserved communities. First, six highly-occurring key words were identified: patient, systemic treatment, locale, hospital, care, and training. Then, standardized keyword frequency analysis robust to overall essay length and keyword volume used individual keywords as "nodes" to calculate per-keyword values for each essay. Finally, Principle Components Analysis and regression were used to analyze key word relationships. RESULTS: Component loadings were strongest for the keyword area, indicating most shared variance. Multiply regressing three of the remaining keywords hospital, systemic treatment, and training yielded R2 = 0.45, considered high for this exploratory study. In contrast, direct patient experience for students was difficult to generalize. CONCLUSIONS: Impressions of the practicing area environment were strongest in students, and these impressions were influenced by hospital workplace, treatment provision, and training. Text mining can extract information from larger samples of student essays in an efficient and objective manner, as well as identify patterns between learning situations to create models of the learning experience. Possible implications for community-based clinical learning may be greater understanding of student experiences for on-site precepts benefitting their roles as mentors.

Utility of Ascitic Fluid Adenosine Deaminase Levels in the Diagnosis of Tuberculous Peritonitis in General Medical Practice.

BACKGROUND: Tuberculous peritonitis is difficult to diagnose due to its varying clinical features, in addition to the low yield on bacterial culture or polymerase chain reaction using ascitic fluid samples. This study aimed to investigate the sensitivity and specificity of elevated adenosine deaminase (ADA) levels as a diagnostic marker for tuberculous peritonitis. METHODS: A retrospective cohort of 181 adult patients who underwent ascitic fluid ADA level examination at Jichi Medical University Hospital between January 2006 and December 2015 were included. We collected data regarding ascitic fluid analyses including ADA levels, bacteriology and cytology, final diagnosis (cause of ascites), basis of the diagnosis, duration to diagnosis, and disease outcome. RESULTS: Among 181 patients, elevated ascitic ADA levels (≥40 IU/L) were observed in 15 patients (median, 87.2 IU/L; range, 44.0-176.1 IU/L); 8 patients had tuberculous peritonitis, 4 had lymphoma-related ascites, and 2,had peritoneal carcinomatosis with bacterial coinfection, and 1 had chlamydial pelvic inflammatory disease. Among 166 patients without ascitic ADA level elevation (median, 7.3 IU/L; range, <2.0-39.1 IU/L), none had tuberculosis, 4 had lymphoma-related ascites, 28 had cancer/mesothelioma-related ascites, and 134 had ascites due to other causes. In our cohort, elevated ascitic fluid ADA levels (≥40 IU/L) showed 100% sensitivity, 96.0% specificity, 53.3% positive predictive value (PPV), and 100% negative predictive value for the diagnosis of peritoneal tuberculosis. CONCLUSIONS: Ascitic fluid ADA levels ≥40 IU/L showed excellent sensitivity, despite a low PPV, for the diagnosis of tuberculous peritonitis. Lymphoma-related ascites is an important mimic of tuberculous peritonitis that can result in high ascitic fluid ADA levels with similar clinical manifestations.

5-aminosalicylic acid agents for prevention of recurrent diverticulitis: A systematic review and meta-analysis.

BACKGROUND AND AIM: Prevalence of colonic diverticulosis is increasing worldwide with age, and up to 25% of patients who have colonic diverticulosis might experience diverticulitis. However, a definitive approach of preventing recurrent diverticulitis remains unknown. 5-aminosalicylic acid (5-ASA) agents are anti-inflammatory agents and have been used to prevent recurrent diverticulitis, and there have been some randomized clinical trials (RCTs). However, the efficacy results for secondary prevention in uncomplicated diverticulitis differed across studies. Our aim was to clarify the efficacy and safety of 5-ASA agents in the prevention of recurrent diverticulitis. METHODS: We searched MEDLINE, EMBASE, Web of Science, and the Cochrane library with no language restrictions. Two reviewers independently assessed and selected RCTs. The data were pooled using a random effect model and were presented in the pooled risk ratio (RR) and 95% confidence interval (CI). Cochrane's Q and I-squared statistics were used to assess heterogeneity. The protocol was registered at PROSPERO. RESULTS: Seven articles with eight RCTs from 329 potentially relevant articles were included. 5-ASA agents were not superior to controls in preventing recurrent diverticulitis (RR 0.86, 95% CI 0.63 to 1.17, I2  = 60%) and the incidence of adverse events was not different between 5-ASA agents and controls (RR 0.97, 95% CI 0.84 to 1.11, I2  = 45%). However, some included studies were few in number of participants and substantial risk of bias. CONCLUSIONS: 5-aminosalicylic acid agents were not associated with prevention of recurrent diverticulitis.

Cytokine profile in adult-onset Still's disease: Comparison with systemic juvenile idiopathic arthritis.

To compare pro-inflammatory cytokine profiles and kinetics in patients with adult-onset Still's disease (AOSD) to those in patients with systemic juvenile idiopathic arthritis (s-JIA), we analyzed serum cytokine concentrations in 33 patients with AOSD and 77 patients with s-JIA and compared them with clinical features. Patients with AOSD and s-JIA shared a common cytokine profile pattern of a significant increase in IL-18. Patients with AOSD were classified into two subgroups based on serum IL-6 and IL-18 levels. The number of patients with arthritis was significantly higher in the IL-6-dominant subgroup. The cytokine patterns associated with s-JIA and AOSD share common features, such as a significant and predominant increase in IL-18. Distinct IL-6- and IL-18-based cytokine profiles might be responsible for distinct clinical manifestations. The presence of two distinct subgroups in patients with both diseases further supports the view that s-JIA and AOSD share a disease category.

Clinically mild encephalitis/encephalopathy with a reversible splenial lesion caused by methicillin-sensitive Staphylococcus aureus bacteremia with toxic shock syndrome: a case report.

BACKGROUND: Clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) is a mild encephalopathy caused by various pathological processes, but encephalopathy due to bacteria is rare. CASE PRESENTATION: We report the case of a 45-year-old Japanese woman who on receiving chemotherapy for advanced breast cancer developed an altered mental status and dysarthria soon after fever from infection of a subcutaneous implantable port. Staphylococcus aureus was detected in her blood cultures. Magnetic resonance imaging (MRI) revealed an ovoid lesion in the central portion of the splenium of the corpus callosum (SCC). Although hypotension was not observed, we diagnosed probable toxic shock syndrome (TSS) based on fever (temperature: >38.9 °C), altered mental status, erythema, desquamation, thrombocytopenia, liver dysfunction, and creatine phosphokinase elevation. We administered antimicrobial therapy and her neurological symptoms improved gradually. The lesion in the SCC completely disappeared on MRI 7 days after disease onset. CONCLUSIONS: We diagnosed this case as MERS caused by S. aureus bacteremia with TSS. This is the first report of such a case, and we suggest that when a TSS patient presents with neurological symptoms, the possibility of MERS should be considered.

A condition closely mimicking IgG4-related disease despite the absence of serum IgG4 elevation and IgG4-positive plasma cell infiltration.

We describe a 74-year-old Japanese man with systemic fibroinflammatory conditions closely resembling those of immunoglobulin G4-related disease (IgG4-RD). Radiology and histology showed characteristics of IgG4-related tubulointerstitial nephritis, despite normal serum IgG4 value and scanty IgG4-positive plasma cell infiltration in each organ. This case suggests that a condition closely mimicking IgG4-RD may develop without IgG4-positive plasma cells and those exceptional cases should also be taken into account in the differential diagnosis of IgG4-RD.

A rare case of anasarca caused by infiltration of the pituitary gland by diffuse large B-cell lymphoma.

BACKGROUND: Anasarca in patients with lymphoma is a rare symptom. We report a patient with DLBCL associated with pituitary gland infiltration that was diagnosed based on significant anasarca. CASE PRESENTATION: A 72-year-old woman with a 10-year history of hypertension visited a local hospital presenting with anasarca and 15-kg weight gain in the past 3 months. we clinically diagnosed central hypothyroidism caused by pituitary gland infiltration of diffuse large B-cell lymphoma (DLBCL) (clinical stage IV in the Ann Arbor staging classification). The first course of chemotherapy improved anasarca remarkably and the patient's body weight returned to what it was 3 months before. CONCLUSIONS: We experienced a patient with remarkable anasarca caused by DLBCL infiltration of the pituitary gland. A pituitary gland lesion with central hypothyroidism should be considered as one of the differential diagnoses of edema. This case was very valuable because we could assess it by following the time course of symptoms (edema and delayed relaxation time of the Achilles tendon reflex), laboratory data, and imaging findings (swelling anterior pituitary lobe).

Primary Sjögren's syndrome with chronic tubulointerstitial nephritis and lymphadenopathy mimicking IgG4-related disease.

We describe a 62-year-old woman with Sjögren's syndrome (SS) presenting with tubulointerstitial nephritis (TIN) and lymphadenopathy mimicking IgG4-related disease (IgG4-RD). Computed tomography revealed multiple swollen lymph nodes. Biopsy of the largest lymph node showed reactive lymphadenopathy with dense IgG4 positive plasma cell (IgG4 + PC) infiltration. Renal biopsy showed chronic plasma cell-rich TIN with IgG4 + PC infiltration. This case suggests that Immunoglobulin G4 immunostaining does not always support the diagnosis of IgG4-RD in the differential diagnosis between SS and IgG4-RD.

Henoch-Schönlein purpura nephritis in a patient with IgG4-related disease: a possible association.

We report a case of Henoch- Schönlein purpura nephritis (HSPN) associated with tubulointerstitial nephritis (TIN) and chronic sclerosing sialoadenitis. The patient is a 75-year-old Japanese woman who had bilateral submandibular gland swelling, palpable purpura on the lower legs, and decreased renal function with hematoproteinuria and marked hypocomplementemia, but no skin lesion suggestive of systemic lupus erythematosus (SLE), and did not fulfill the classification criteria for SLE. Her serum IgG4 level was high and immunostaining of renal biopsies revealed marked infiltration by IgG4-positive plasma cells in the interstitium, confirming the diagnosis of IgG4- related disease. On the other hand, glomeruli showed endocapillary proliferative glomerulonephritis with mesangial IgA and C3 deposition demonstrated by immunofluorescence staining, which were typical glomerular lesions for HSPN. The glomerular and tubulointerstitial lesions responded to steroid therapy dramatically, and her renal function recovered to within the normal range within a month. This case suggests a possible new association between HSPN and IgG4-related disease.

A case of refractory cutaneous polyarteritis nodosa in a patient with hepatitis B carrier status successfully treated with tumor necrosis factor alpha blockade.

We describe a patient with refractory cutaneous polyarteritis nodosa (CPAN) with hepatitis B virus (HBV) carrier status who was successfully treated with tumor necrosis factor alpha (TNF-α) blockade, using etanercept, and we review 5 similar cases. We administered etanercept because of the occurrence of repeated flares despite aggressive therapy. C-reactive protein normalization; prednisolone dose-sparing; and absence of any adverse events, including HBV reactivation with nucleotide analogue administration, or renal dysfunction, have been achieved for 8 months. TNF-α blockade should be considered for intractable CPAN.

A case of Behçet's-like disease associated with trisomy 8-positive myelodysplastic syndrome carrying MEFV E148Q variant presented with periodic fever.

Behçet's-like disease, which incompletely fulfils the criteria of Behçet's disease, is often associated with trisomy 8-positive myelodysplastic syndrome (MDS). We report a case of an 82-year-old man with these conditions carrying the E148Q variant of MEFV gene who presented with periodic fever. The patient presented with joint pain, muscle pain, and episodes of periodic fever every 2 weeks for the past 3 months. On admission, painful erythema and fever were observed. Colonoscopy revealed erosion in the caecum and ascending colon. The patient had bicytopenia, and a bone marrow biopsy showed findings compatible with trisomy 8-positive unclassifiable MDS. Because the patient incompletely fulfilled the criteria for Behçet's disease, he was diagnosed with Behçet's-like disease associated with trisomy 8-positive MDS. Positron emission tomography-computed tomography performed during the fever revealed multiple muscle lesions consistent with the sites of pain. To examine the cause of the periodic fever attacks, MEFV gene was analysed, and the results revealed an E148Q variant. Steroids were ineffective against periodic fever attacks. A daily dose of 0.5 mg colchicine was prescribed, but the effect was minimal, probably, because of the insufficient dose due to renal dysfunction. Based on the diagnosis of atypical familial Mediterranean fever, canakinumab was added, which partially mitigated the periodic fever. This case suggests the importance of ruling out MDS when physicians see an elderly patient who present with Behçet's-like disease. Although the significance of the E148Q variant in the pathogenesis of periodic fever remains controversial, it may act as a disease modifier in accordance with trisomy 8-positive MDS.

Performance of serum soluble interleukin-2 receptor as a diagnostic marker for lymphoma in patients with fever.

There have been few reports on the diagnostic performance of soluble interleukin-2 receptor (sIL-2R) for lymphoma. A cross-sectional study was conducted at a university hospital; all patients who were admitted to the Division of General Internal Medicine and underwent serum sIL-2R testing were included. Patients were divided into two groups based on the presence of fever (≥ 38.0 °C). Among 602 patients, 421 had fever and 76 were diagnosed with lymphoma (48 of the 76 were in the febrile group). In all patients, the area under the receiver operating characteristic curve (AUROC) of sIL-2R for the diagnosis of lymphoma was 0.81 [95% confidence interval (CI), 0.75-0.87]. The AUROC was significantly higher in the febrile group (0.88; 95% CI, 0.81-0.94) than in the afebrile group (0.75; 95% CI, 0.65-0.85). In the febrile group, the sensitivity and specificity were 81.2% and 82.3%, respectively, with an optimal cutoff value of 3,250 U/mL. In the afebrile group, they were 89.3% and 54.9%, respectively, with a cutoff value of 868 U/mL. Serum sIL-2R showed high performance as an adjunctive diagnostic marker for lymphoma, particularly among febrile patients. Different cutoff values should be used for patients with and without fever to maximize diagnostic performance.

Serum 25-hydroxycholesterol levels are increased in patients with coronavirus disease 2019.

BACKGROUND: 25-hydroxycholesterol (25HC), produced by cholesterol 25-hydroxylase (CH25H) in macrophages, has been reported to inhibit the replication of viral pathogens such as severe acute respiratory syndrome coronavirus-2. Also, CH25H expression in macrophages is robustly induced by interferons (IFNs). OBJECTIVE: To better understand the serum level increase of 25HC in coronavirus disease 2019 (COVID-19) and how it relates to the clinical picture. METHODS: We measured the serum levels of 25HC and five other oxysterols in 17 hospitalized COVID-19 patients. RESULTS: On admission, 25HC and 27-hydroxycholesterol (27HC) serum levels were elevated; however, 7-ketocholesterol (7KC) levels were lower in patients with COVID-19 than in the healthy controls. There was no significant correlation between 25HC serum levels and disease severity markers, such as interferon-gamma (IFN-γ) and interleukin 6. Dexamethasone effectively suppressed cholesterol 25-hydroxylase (CH25H) mRNA expression in RAW 264.7 cells, a murine leukemia macrophage cell line, with or without lipopolysaccharide or IFNs; therefore, it might mitigate the increasing effects of COVID-19 on the serum levels of 25HC. CONCLUSIONS: Our results highlighted that 25HC could be used as a unique biomarker in severe COVID-19 and a potential therapeutic candidate for detecting the severity of COVID-19 and other infectious diseases.

Clinical and histological changes associated with corticosteroid therapy in IgG4-related tubulointerstitial nephritis.

OBJECTIVES: This study aimed to investigate the clinicopathological changes induced by corticosteroid therapy in immunoglobulin (Ig)G4-related tubulointerstitial nephritis (TIN). METHODS: We studied six IgG4-related TIN patients receiving renal biopsies before and after corticosteroid therapy. Their clinical data and histological findings were evaluated before and after therapy. RESULTS: Elevated serum creatinine levels rapidly improved after corticosteroid therapy except for two patients, in whom it persisted. Abnormal radiological findings improved in all patients, although focal cortical atrophy persisted in three. Histologically, TIN-like dense lymphoplasmacytic infiltration, interstitial fibrosis, IgG4-positive plasma cell, CD4+CD25+ T cell, and Foxp3+ cell infiltration were characteristic before therapy. After therapy, the area with cell infiltration decreased and regional fibrosis became evident in the renal interstitium. The number of IgG4-positive plasma cells and Foxp3+ cells significantly diminished even in the early stage of therapy, whereas low to moderate numbers of CD4+ and CD8+ T cells still infiltrated where inflammation persisted in the later stage. CONCLUSIONS: Our study shows that persistent renal insufficiency associated with macroscopic atrophy and microscopic fibrosis is not so rare in IgG4-related TIN. Pathologically, the behavior of regulatory T cells during the clinical course is quite similar to that of IgG4-positive plasma cells, and the behavior pattern of those cells is distinctive.

Palmar Fasciitis and Polyarthritis Syndrome Associated with Lung Adenocarcinoma.

Palmar fasciitis and polyarthritis syndrome (PFPAS) is a rare paraneoplastic rheumatic disease with characteristic features. We herein report a 77-year-old man with lung adenocarcinoma and contralateral pulmonary metastasis receiving chemotherapy who presented with progressive symmetrical flexion contractures associated with palmar fascial thickening and arthritis of both hands and shoulders. He was diagnosed with PFPAS as paraneoplastic manifestations. Salazosulfapyridine was not effective, but 15 mg/day of oral prednisolone improved his symptoms. Physicians should consider PFPAS and rule out malignancy in patients with arthritis in the extremities and flexion contractures associated with palmar fascial thickening.

Blood Gas Analysis Results and Serum Lactate Levels in Patients with Psychogenic Hyperventilation and Urinary Tract Infection with Suspected Sepsis: A Retrospective Comparative Study.

Objective The prognosis differs considerably between patients with psychogenic hyperventilation syndrome (HVS) and those with urinary tract infection (UTI)-associated sepsis; however, the nonspecific symptoms and signs make the diagnosis and management difficult. We herein report the utility of a blood gas analysis for distinguishing HVS from UTI with suspected sepsis. Methods This single-center retrospective cohort study was conducted in a tertiary-care hospital in Japan. Patients ≥18 years old with a quick Sequential Organ Failure Assessment (qSOFA) score ≥2 and HVS or UTIs were included. The results of an arterial blood gas (ABG) or venous blood gas (VBG) analysis of the two groups were compared using the Mann-Whitney U test. We used a receiver-operating characteristic (ROC) curve analysis of the arterial pH and arterial PCO2 to assess the ability of these analyses to distinguish HVS from UTI with suspected sepsis. Results A total of 64 patients with HVS (ABG, n=14; VBG, n=50) and 53 with UTI with suspected sepsis (ABG, n=35; VBG, n=18) were included. Patients with HVS had alkalemia and lower PCO2 levels than patients with UTI with suspected sepsis, but the serum lactate levels were similar between the groups. The ROC analysis determined the pH cut-off value to be 7.509 (sensitivity: 0.91; specificity: 0.86) and the PCO2 cut-off value to be 21.6 mmHg (sensitivity: 1.00; specificity: 0.64). Conclusion Elevated serum lactate levels alone cannot be used to differentiate between patients with HVS and those with UTI with suspected sepsis, but the degree of pH and PCO2 abnormality can help with the differential diagnosis.