Dynamics of iron metabolism in patients with bloodstream infections: a time-course clinical study.

The close relationship between infectious diseases and iron metabolism is well known, but a more detailed understanding based on current knowledge may provide new insights into the diagnosis and treatment of infectious diseases, considering the growing threat of antibiotic-resistant bacteria. This study investigated adult patients with bloodstream infections, temporal changes, and relationships between blood levels of iron and related markers, including hepcidin and lipocalin-2 (LCN2). We included 144 samples from 48 patients (mean age 72 years, 50% male), with 30 diagnosed with sepsis. During the acute phase of infection, blood levels of hepcidin and LCN2 increased rapidly, whereas iron levels decreased, with values in 95.8% of cases below the normal range (40-188 µg/dL). Later, hepcidin and LCN2 decreased significantly during the recovery phase, and the decreased iron concentrations were restored. In the case of persistent inflammation, iron remained decreased. Acute LCN2 levels were significantly higher in patients with sepsis (p < 0.01). Hypoferremia induced by increased hepcidin would reduce iron in the environment of extracellular pathogens, and the increased LCN2 would inhibit siderophores, resulting in the prevention of the pathogen's iron acquisition in each manner during the acute phase of bloodstream infection.

Factors associated with cytomegalovirus antigenemia in patients with rheumatic disease: A retrospective study.

INTRODUCTION: This study aimed to examine the factors associated with cytomegalovirus (CMV) antigenemia and the time of onset of CMV antigenemia among patients with rheumatic diseases. METHODS: A single-center, retrospective, observational study was conducted in our institution from January 2009 to December 2017. This study included patients with rheumatic diseases who had at least one CMV antigen measurement. Multivariate analysis and receiver operating characteristic analysis was performed. RESULTS: A total of 249 patients underwent CMV antigenemia assay, and 84 (33.7%) patients tested positive. When the association between CMV antigenemia and possible associated factors was investigated, multivariate analysis showed that daily steroid dose increased the odds of having CMV [odds ratio 16.25, 95% confidence interval (CI), 5.360-49.253]. In this study, the cutoff value of daily steroid dose found in this study (0.45 mg/kg/day) was reasonable in clinical practice, and the area under the curve of the steroid dose was 0.838 [95% CI 0.781-0.882], which was the largest of the known indicators. Moreover, the median time from the start of immunosuppressive therapy to the onset of CMV antigenemia was 30 (interquartile range, 21-44) days, and most of the daily steroid users (85.7%) developed CMV antigenemia within 60 days. CONCLUSIONS: The daily steroid dose is the most important factor associated with CMV antigenemia. Therefore, monitoring and treatment strategies based on the steroid dose, especially in the initial 2 months, are important.

An outbreak of serotype 19A pneumococcal pneumonia in a relief facility in Japan.

An outbreak of serotype 19A Streptococcus pneumoniae occurred among the residents of a relief facility. Pneumonia developed in 5 of 99 residents (attack rate, 5.1%). We obtained pharyngeal specimens from non-onset residents, and S. pneumoniae was isolated from 6 individuals (6.4%), 5 of whom had serotype 19A.

Efficacy of the new ß-D-glucan measurement kit for diagnosing invasive fungal infections, as compared with that of four conventional kits.

BACKGROUND: Each of the currently available (1→3)-ß-D-glucan (BDG) measurement kits follows a different measurement method and cut-off value. Comparisons of diagnostic performance for invasive fungal infections (IFIs) are desirable. Additionally, ecological considerations are becoming increasingly important in the development of new measurement kits. METHODS: The plasma BDG levels in clinical samples were measured using the following currently available kits: the Fungitec G test MKII, the Fungitec G test ES, Fungitell, the ß-Glucan test Wako, and the newly developed Wako kit (Wako-Eu). Wako-Eu uses a pre-treatment solution that conforms to European regulations for the registration, evaluation, authorisation, and restriction of chemicals. The values obtained for the samples using each kit were studied and compared. RESULTS: Of the 165 patients evaluated, 12 had IFIs, including pneumocystis pneumonia, aspergillosis, and candidiasis. BDG values obtained using the kits were moderately correlated with each other. Clinical diagnoses of the evaluated cases indicated that 21 false positives were diagnosed by at least one kit. The sensitivity of the Fungitell kit was relatively low, but those of the other four were over 90%. The specificity was above 90% for all kits. For positive predictive value, the Wako and the Wako-Eu methods were superior to the others owing to fewer false positive results. CONCLUSIONS: The newly developed Wako-Eu method, which considers ecological concerns, shows diagnostic performance equivalent to that of its predecessor. To improve the diagnostic accuracy of IFIs, it is necessary to interpret the results carefully, giving due consideration to the characteristics of each measurement kit.

Multiplex cytokine analysis in Mycobacterium avium complex lung disease: relationship between CXCL10 and poor prognostic factors.

BACKGROUND: Mycobacterium avium complex lung disease (MAC-LD) can deteriorate rapidly to become fatal. Reported poor prognostic factors include radiographic findings, undernutrition, anemia and high inflammation test values. However, the association of these prognostic factors with the pathophysiology of the disease remains unknown. We aimed to clarify the pathophysiology of MAC-LD and develop a new biomarker that reflects the immune response to the disease. METHODS: We performed the cytokine panel analyses of serum from patients with MAC-LD and compared each cytokine level with clinically negative prognostic factors (radiographic disease type, body mass index, albumin, C-reactive protein and hemoglobin) and high-resolution CT scores. RESULTS: We analyzed 27 patients with MAC-LD, 6 with the fibrocavitary form and 21 with the nodular bronchiectatic form on high-resolution CT. Serum CXC motif ligand 10 (CXCL10) concentration was significantly elevated in patients with the fibrocavitary form (p = 0.008). CXCL10 levels correlated with body mass index (r = - 0.60, p = 0.0008), serum albumin concentration (r = - 0.45, p = 0.016) and high-resolution CT scores (r = 0.61, p = 0.0006). Among 14 patients initially untreated, antibiotic therapy was initiated for five during the study period. CXCL10 concentration was significantly higher in these patients (p = 0.046), and receiver operating characteristic analysis for CXCL10 concentration on treatment initiation produced an area under the curve of 0.844, with a sensitivity of 100%, specificity of 66.7%, and cut-off value of 366.5 pg/mL. CONCLUSION: We revealed cytokine profiles in patients with MAC-LD. Serum CXCL10 levels probably reflect the severity of MAC-LD. Our findings suggest that CXCL10 concentration may be a promising biomarker for managing treatment for patients with MAC disease of the lung.

Increased presepsin levels are associated with the severity of fungal bloodstream infections.

BACKGROUND: Presepsin is a widely recognized biomarker for sepsis. However, little is known about the usefulness of presepsin in invasive fungal infection. The aim of this study was to determine the plasma levels of presepsin in fungal bloodstream infections and to investigate whether it reflects the disease severity, similar to its utility in bacterial infections. METHODS: We prospectively measured presepsin in plasma samples from participants with fungemia from April 2016 to December 2017. The associations of C-reactive protein, procalcitonin, and presepsin concentrations with the severity of fungemia were statistically analyzed. In vitro assay was performed by incubating Escherichia coli, Candida albicans, and lipopolysaccharide to whole blood cells collected from healthy subjects; after 3 h, the presepsin concentration was measured in the supernatant and was compared among the bacteria, fungi, and LPS groups. RESULTS: Presepsin was increased in 11 patients with fungal bloodstream infections. Serial measurement of presepsin levels demonstrated a prompt decrease in 7 patients in whom treatment was effective, but no decrease or further increase in the patients with poor improvement. Additionally, presepsin concentrations were significantly correlated with the Sequential Organ Failure Assessment score (r = 0.89, p < 0.001). In vitro assay with co-incubation of C. albicans and human whole blood cells indicated that the viable cells of C. albicans caused an increase in presepsin, as seen with E. coli. CONCLUSIONS: Plasma presepsin levels increased in patients with fungal bloodstream infection, with positive association with the disease severity. Presepsin could be a useful biomarker of sepsis secondary to fungal infections.

[The Effect of Intravenous Gamma-globulin Reagents on the Measurement Results of (1➔3)-ß-D-glucan].

Serum (1→3) beta-D-glucan (BG) measurement is a useful test for systemic mycoses, and often used. On the other hand, various factors, including administration of intravenous immunoglobulins (IVIG) may cause false-positives. In the present study, we measured BG concentration of seven IVIG preparations with three lots respectively. BG levels varied with individual IVIG preparations (<3.0 - >300 pg/mL), and contamination from manufacturing processes was suspected. With serum BG concentration of clinical specimens obtained in Niigata University Medical & Dental Hospital, the difference between before and after administration of IVIG were calculated. The false-positive rate of BG due to IVIG administration was 9.8 %, and the positive predective value was reduced to 37.5%. Above all, administration of IVIG can complicate the BG test's interpretation, and caution is required.