Rapid implementation of home oxygen treatment and remote monitoring for COVID-19 patients at the verge of the Omicron wave in Turku, Finland

BACKGROUND

In Turku, Finland, we introduced a home oxygen treatment and app-based monitoring program for hospitalized COVID-19 patients to facilitate an early discharge during the Omicron wave. In this case series we explore the clinical parameters of patients enrolled in the program and evaluate the cost-benefit and safety issues of the program.

METHODS

Hospitalized COVID-19 patients with marked hypoxemia but otherwise in stable condition were screened from Turku City Hospital and Turku University Hospital by treating doctors for eligibility in the program. Peripheral oxygen saturation of > 92% and breathing frequency < 30/min in rest with oxygen supplementation were among the criteria. All patients actively participating in the program between 10th of January 2022 and 30th of September 2022 were included in this case series. Clinical data of hospitalization and monitoring were analysed, and cost-benefit evaluation was based on the number of saved hospitalization days.

RESULTS

Nineteen COVID-19 patients were included in this case series and recruited from three different hospital departments in the Turku city region, South-West Finland. All patients were male, the median age was 59 years and the median duration of hospitalization before enrolment in the program was 6 days (range 3-20 days). The median duration of home oxygen treatment was 13 days (range 3-72 days) and the median duration of home monitoring was 18 days (range 7-41 days). A total of 210,5 hospital days were prevented, resulting in savings of €144,490 of healthcare expenditure (on average 9 days and €7,605 per patient). No major safety issues were reported during the program.

CONCLUSIONS

In our case series, home oxygen treatment combined with home monitoring was safe and economically beneficial. Application based monitoring could be considered in other post-acute pulmonary conditions to reduce hospitalization and healthcare costs.

Early administration of tocilizumab in hospitalized COVID-19 patients with elevated inflammatory markers; COVIDSTORM-a prospective, randomized, single-centre, open-label study

OBJECTIVES

Severe COVID-19 is associated with an imbalanced immune response. We hypothesized that patients with enhanced inflammation, as demonstrated by increased levels of certain inflammatory biomarkers, would benefit from interleukin-6 blockage.

METHODS

Patients hospitalized with COVID-19, hypoxemia, and at least two of four markedly elevated markers of inflammation (interleukin-6, C-reactive protein, ferritin, and/or D-dimer) were randomized for tocilizumab (TCZ) plus standard of care (SoC) or SoC alone. The primary endpoint was clinical status at day 28 assessed using a seven-category ordinal scale, and the secondary endpoints included intensive care unit admission, respiratory support, and duration of hospital admission.

RESULTS

Clinical status at day 28 was significantly better in patients who received TCZ in addition to SoC compared with those who received SoC alone (p = 0.037). By then, 93% of patients who received TCZ (n = 53 of 57) and 86% of control patients (n = 25 of 29) had been discharged from the hospital. In addition, 47% of TCZ patients (n = 27 of 57) and 24% of control patients (n = 7 of 29) had resumed normal daily activities. The median length of hospitalization was 9 days (interquartile range, 7-12) in the TCZ group and 12 days (interquartile range, 9-15) in the control group (p = 0.014).

DISCUSSION

In patients hospitalized with COVID-19, hypoxemia, and elevated inflammation markers, administration of TCZ in addition to SoC was associated with significantly better clinical recovery by day 28 and a shorter hospitalization compared with SoC alone.

68Ga-Citrate Positron Emission Tomography of Healthy Men: Whole-Body Biodistribution Kinetics and Radiation Dose Estimates

⁶⁸Ga-citrate has one of the simplest chemical structures of all ⁶⁸Ga-radiopharmaceuticals, and its clinical use is justified by the proven medical applications using its isotope-labeled compound ⁶⁷Ga-citrate. To support broader application of ⁶⁸Ga-citrate in medical diagnosis, further research is needed to gain clinical data from healthy volunteers. In this work, we studied the biodistribution of ⁶⁸Ga-citrate and subsequent radiation exposure from it in healthy males. Methods: ⁶⁸Ga-citrate was prepared with an acetone-based radiolabeling procedure compliant with Good Manufacturing Practices. Six healthy males (age 41 ± 12 years, mean ± SD) underwent sequential whole-body PET/CT scans after an injection of 204 ± 8 MBq of ⁶⁸Ga-citrate. Serial arterialized venous blood samples were collected during PET imaging and the radioactivity concentration was measured with a gamma counter. Urinary voids were collected and measured. The Medical Internal Radiation Dose (MIRD) bladder-voiding model with a 3.5 hour voiding interval was used. A model using a 70 kg adult male and MIRD schema was used to estimate absorbed doses in target organs and effective doses. Calculations were performed using OLINDA/EXM 2.0 software. Results: Radioactivity clearance from the blood was slow, and relatively high radioactivity concentrations were observed over the whole of the 3 hour measuring period. Although radioactivity excretion via urine was rather slow (biological half-time, 69 ± 24 hours), the highest decay-corrected concentrations in urinary bladder contents were measured at 90 and 180 minute time points. Moderate concentrations were also seen in kidneys, liver, and spleen. The source organs showing the largest residence times were muscle, liver, lung, and heart contents. The heart wall received the highest absorbed dose of 0.077 ± 0.008 mSv/MBq. The mean effective dose (ICRP 103) was 0.021 ± 0.001 mSv/MBq. Conclusion: PET imaging with ⁶⁸Ga-citrate is associated with modest radiation exposure. A 200 MBq injection of ⁶⁸Ga-citrate results in an effective radiation dose of 4.2 mSv, which is in the same range as other ⁶⁸Ga-labeled tracers. This suggests the feasibility of clinical studies using ⁶⁸Ga-citrate imaging in humans and the possibility of performing multiple scans in the same subjects across the course of a year.

IL-6 and other biomarkers as predictors of severity in COVID-19

OBJECTIVE

Cytokine release syndrome is suggested to be the most important mechanism triggering acute respiratory distress syndrome and end organ damage in COVID-19. The severity of disease may be measured by different biomarkers.

METHODS

We studied markers of inflammation and coagulation as recorded in 29 patients on admission to the hospital in order to identify markers of severe COVID-19 and need of ICU.

RESULTS

Patients who were eventually admitted to ICU displayed significantly higher serum levels of interleukin-6 (IL-6), C-reactive protein (CRP), and procalcitonin. No statistical differences were found between the groups in median levels of lymphocytes, D-dimer or ferritin.

CONCLUSIONS

IL-6 and CRP were the strongest predictors of severity in hospitalized patients with COVID-19.

18F-FDG positron emission tomography/computed tomography of cardiac implantable electronic device infections

BACKGROUND

The diagnosis of cardiac implantable electronic device (CIED) infection is challenging because of its variable presentations. We studied the value of 2-[18F]fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in the detection of CIED infection.

METHODS AND RESULTS

Thirty patients with suspected CIED infection underwent 18F-FDG-PET/CT. The control group was ten patients with asymptomatic CIED who underwent cancer-related 18F-FDG-PET/CT. 18F-FDG-PET/CT was evaluated visually, semiquantitatively as maximum standardized uptake value (SUVmax) and target-to-background ratio (TBR). Final diagnosis of CIED infection was based on clinical and bacteriological data. 18F-FDG-PET/CT was visually positive in all 9 patients with recent (≤ 8 weeks) implantation of CIED, but only 4 had confirmed CIED infection. 18F-FDG-PET/CT was true positive in 9 out of 21 cases with remote implantation of CIED and false positive in 3 (14.3%) cases. 18F-FDG-PET/CT was also false positive in 3 (30%) cases of control group. The SUVmax of the pocket area was significantly higher in patients with CIED infection than in the control group (4.8 ± 2.4 vs 2.0 ± .8, P < .001). By using the cut-off value of TBR ≥ 1.8, sensitivity of 18F-FDG-PET/CT for the diagnosis of CIED infection in patients with remote implantation was 90% and specificity 73%, PPV 75%, and NPV 89%.

CONCLUSIONS

18F-FDG-PET/CT is a sensitive but nonspecific method in the diagnosis of CIED infection.

Rapid detection of bacterial infection using a novel single-tube, four-colour flow cytometric method: Comparison with PCT and CRP

BACKGROUND

A key factor behind the unnecessary use of antibiotics is the lack of rapid and accurate diagnostic tests. In this study, we developed a novel and fast flow cytometric single-tube method to detect bacterial infections within 30 minutes.

METHODS

Quantitative flow cytometric four-colour analysis of host biomarkers CD35, CD64, CD329, and MHC class I expression on neutrophils and lymphocytes was performed on samples taken from 841 febrile patients with suspected infection. Obtained data was incorporated into the four-colour bacterial infection (FCBI)-index, using the developed bacterial infection algorithm.

FINDINGS

In distinguishing between microbiologically confirmed bacterial (n = 193) and viral (n = 291) infections, the FCBI-index method was superior to serum C-reactive protein (CRP) and procalcitonin (PCT). In 269 confirmed viral respiratory tract infections, 43% (95% CI: 37-49%) of the patients had an increased FCBI-index, suggesting probable bacterial coinfection.

INTERPRETATION

The proposed FCBI-index test might be a potent additional tool when assessing appropriateness of empiric antibiotic treatment.

FUNDING

This study has been financially supported by Turku University Hospital (Turku, Finland) and The Finnish Medical Foundation.

Fungemia and Other Fungal Infections Associated with Use of Saccharomyces boulardii Probiotic Supplements

Use of these supplements should be considered carefully for patients whose gastrointestinal tract integrity might be compromised.

Because of widespread use of probiotics, their safety must be guaranteed. We assessed use of Saccharomyces boulardii probiotic yeast from medical records for patients who had Saccharomyces fungemia or other clinical Saccharomyces culture findings. We evaluated all Saccharomyces sp. findings at 5 university hospitals in Finland during 2009–2018. We found 46 patients who had Saccharomyces fungemia; at least 20 (43%) were using S. boulardii probiotic. Compared with a control group that had bacteremia or candidemia, the odds ratio for use of an S. boulardii probiotic was 14 (95% CI 4–44). Of 1,153 nonblood culture findings, the history for 125 patients was checked; at least 24 (19%) were using the probiotic (odds ratio 10, 95% CI 3–32). This study adds to published fungemia cases linked to use of S. boulardii probiotic and sheds light on the scale of nonblood Saccharomyces culture findings that are also linked to use of this probiotic.

Oral Doxycycline Compared to Intravenous Ceftriaxone in the Treatment of Lyme Neuroborreliosis: A Multicenter, Equivalence, Randomized, Open-label Trial

BACKGROUND

Lyme neuroborreliosis (LNB) is often treated with intravenous ceftriaxone even if doxycycline is suggested to be noninferior to ceftriaxone. We evaluated the efficacy of oral doxycycline in comparison to ceftriaxone in the treatment of LNB.

METHODS

Patients with neurological symptoms suggestive of LNB without other obvious reasons were recruited. The inclusion criteria were (1) production of Borrelia burgdorferi-specific antibodies in cerebrospinal fluid (CSF) or serum; (2) B. burgdorferi DNA in the CSF; or (3) an erythema migrans during the past 3 months. Participants were randomized in a 1:1 ratio to receive either oral doxycycline 100 mg twice daily for 4 weeks, or intravenous ceftriaxone 2 g daily for 3 weeks. The participants described their subjective condition with a visual analogue scale (VAS) from 0 to 10 (0 = normal; 10 = worst) before the treatment, and 4 and 12 months after the treatment. The primary outcome was the change in the VAS score at 12 months.

RESULTS

Between 14 September 2012 and 28 December 2017, 210 adults with suspected LNB were assigned to receive doxycycline (n = 104) or ceftriaxone (n = 106). The per-protocol analysis comprised 82 patients with doxycycline and 84 patients with ceftriaxone. The mean change in the VAS score was -3.9 in the doxycycline group and -3.8 in the ceftriaxone group (mean difference, 0.17 [95% confidence interval, -.59 to .92], which is within the prespecified equivalence margins of -1 to 1 units). Participants in both groups improved equally.

CONCLUSIONS

Oral doxycycline is equally effective as intravenous ceftriaxone in the treatment of LNB.

CLINICAL TRIALS REGISTRATION

NCT01635530 and EudraCT 2012-000313-37.

Capnocytophaga canimorsus: a rare case of conservatively treated prosthetic valve endocarditis

We describe a rare case of prosthetic valve endocarditis caused by the canine bacterium Capnocytophaga canimorsus in a male aged 73 years. The diagnosis of infective endocarditis was unequivocal, as it blood cultures were positive for C. canimorsus and vegetations were detected on transesophageal echocardiography; the modified Duke criteria were fulfilled. PET-CT showed intense ¹⁸ F-FDG uptake of the prosthetic valve area. The patient was treated with antibiotics alone (no surgery), and is now on life-long suppressive antibiotic therapy. To our knowledge, this is the third reported case of prosthetic valve endocarditis caused by C. canimorsus and the first one to have been treated conservatively.

18F-FDG positron emission tomography/computed tomography in infective endocarditis

BACKGROUND

The diagnosis of infective endocarditis (IE), especially the diagnosis of prosthetic valve endocarditis (PVE) is challenging since echocardiographic findings are often scarce in the early phase of the disease. We studied the use of 2-[18F]fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in IE.

METHODS

Sixteen patients with suspected PVE and 7 patients with NVE underwent visual evaluation of 18F-FDG-PET/CT. 18F-FDG uptake was measured also semiquantitatively as maximum standardized uptake value (SUVmax) and target-to-background ratio (TBR). The modified Duke criteria were used as a reference.

RESULTS

There was strong, focal 18F-FDG uptake in the area of the affected valve in all 6 cases of definite PVE, in 3 of 5 possible PVE cases, and in 2 of 5 rejected cases. In all patients with definite PVE, SUVmax of the affected valve was higher than 4 and TBR higher than 1.8. In contrast to PVE, only 1 of 7 patients with NVE had uptake of 18F-FDG by PET/CT in the valve area. Embolic infectious foci were detected in 58% of the patients with definite IE.

CONCLUSIONS

18F-FDG-PET/CT appears to be a sensitive method for the detection of paravalvular infection associated with PVE. Instead, the sensitivity of PET/CT is limited in NVE.

Scedosporium apiospermum as a rare cause of central skull base osteomyelitis

We report a case of Scedosporium apiospermum mold causing ear infection, central skull base osteomyelitis and finally, occlusion of carotid artery in a 48-year-old diabetic man. The exact diagnosis was established and the severity of the disease understood several months after the onset of symptoms. Despite of appropriate antifungal therapy, and repeated surgical and otological procedures, the infection progressed to fatal cerebral infarction.

Clinical picture and overall status of newly diagnosed HIV patients at Turku University Hospital in 2013

Our patient material consists of the 12 patients diagnosed during one year. In all cases, sex was the likely mode of transmission, the number of partners having been high for some patients. Some of the cases were originally detected as a result of contact tracing. In two patients the disease had already at the time of diagnosis progressed to the AIDS stage, naturally complicating the initial phase of treatment. In a quarter of our patients the disease could have been discovered earlier from the symptoms of the primary infection, provided that testing had been done. Adherence to treatment in a HIV patient and treatment outcome are usually excellent.

Constant high adrenal FDG uptake in PET/CT associated with mitochondrial disease

We describe a patient with the m.3243A>G mitochondrial DNA mutation who developed sepsis caused by Streptococcus constellatus. In the acute phase of illness, abnormally high uptake of (18)F-FDG was observed in both adrenal glands that appeared anatomically normal. In repeated imaging six months later the adrenal uptake had diminished but remained clearly elevated. We did not observe high adrenal FDG uptake as in the patient described here among 30 patients with Staphylococcus aureus sepsis that were investigated with identical imaging protocol. In sepsis, oxygen consumption and metabolic rate are increased compared to normal metabolism. The observed high adrenal FDG uptake during sepsis in this patient probably reflects the acute metabolic stress induced by the infection. Interestingly, in repeated imaging six months later, the adrenal SUVs had diminished but were still abnormally high: this suggests constant high levels of metabolic stress associated with the mitochondrial disorder.

[Cerebral nocardiosis as surprising cause of a convulsive seizure]

Underlying a convulsive seizure of an adult patient many different types of cause can be detected, such as alcohol withdrawal, disturbance of the cerebral circulation, cerebral hemorrhage, brain tumor, metabolic disturbances, drugs or infection. In connection with severe central nervous system infections, such as brain abscesses, convulsive seizures occur in approximately one out of five patients. A patient with brain abscess may be nonfebrile and have normal values of inflammatory markers. The diagnosis is based on contrast-enhanced CT scanning or magnetic resonance imaging of the brain. Even surgical sampling is often necessary. In our patient, a rare nocardia-induced brain abscess turned out to be the cause of recurrent convulsive seizures.

Candida dubliniensis spondylodiscitis in an immunocompetent patient. Case report and review of the literature

We describe what appears to be the first case of spondylodiscitis due to Candida dubliniensis. Our case adds to the current literature of the importance of C. dubliniensis as a cause of fungemia and subsequent deep seated infections. It highlights the importance of taking fungal as well as bacterial culture from biopsy specimens in patients with spondylodiscitis. We also review the literature covering the reported cases of Candida spondylodiscitis, which amount to about 100 over the last 5 decades.

Bacterial infection (BI)-INDEX: an improved and simplified rapid flow cytometric bacterial infection marker

The aim of this study was to develop a rapid and simple flow cytometric bacterial infection marker. In this prospective comparative study, quantitative flow cytometric analysis of CD10, CD35, CD66b, CD282, and MHC Class I molecules on human neutrophils, monocytes, and B-lymphocytes from 141 hospitalized febrile patients with suspected infection and from 50 healthy controls was performed. We developed a flow cytometric marker of local and systemic bacterial infections, designated "bacterial infection (BI)-INDEX", incorporating the quantitative analysis of CD10, CD35, MHCI, CD66b, and CD282 on neutrophils, monocytes, and B-lymphocytes, which displayed 90% sensitivity and 96% specificity in distinguishing between microbiologically confirmed bacterial (n = 31) and viral infections (n = 27) within a 1-h time-frame. We propose that our novel rapid BI-INDEX test will be useful in assisting physicians to ascertain whether antibiotic treatment is required, thus limiting unnecessary antimicrobial usage.

Estimating the burden of pneumococcal pneumonia among adults: a systematic review and meta-analysis of diagnostic techniques

Background

Pneumococcal pneumonia causes significant morbidity and mortality among adults. Given limitations of diagnostic tests for non-bacteremic pneumococcal pneumonia, most studies report the incidence of bacteremic or invasive pneumococcal disease (IPD), and thus, grossly underestimate the pneumococcal pneumonia burden. We aimed to develop a conceptual and quantitative strategy to estimate the non-bacteremic disease burden among adults with community-acquired pneumonia (CAP) using systematic study methods and the availability of a urine antigen assay.

Methods and Findings

We performed a systematic literature review of studies providing information on the relative yield of various diagnostic assays (BinaxNOW® S. pneumoniae urine antigen test (UAT) with blood and/or sputum culture) in diagnosing pneumococcal pneumonia. We estimated the proportion of pneumococcal pneumonia that is bacteremic, the proportion of CAP attributable to pneumococcus, and the additional contribution of the Binax UAT beyond conventional diagnostic techniques, using random effects meta-analytic methods and bootstrapping. We included 35 studies in the analysis, predominantly from developed countries. The estimated proportion of pneumococcal pneumonia that is bacteremic was 24.8% (95% CI: 21.3%, 28.9%). The estimated proportion of CAP attributable to pneumococcus was 27.3% (95% CI: 23.9%, 31.1%). The Binax UAT diagnosed an additional 11.4% (95% CI: 9.6, 13.6%) of CAP beyond conventional techniques. We were limited by the fact that not all patients underwent all diagnostic tests and by the sensitivity and specificity of the diagnostic tests themselves. We address these resulting biases and provide a range of plausible values in order to estimate the burden of pneumococcal pneumonia among adults.

Conclusions

Estimating the adult burden of pneumococcal disease from bacteremic pneumococcal pneumonia data alone significantly underestimates the true burden of disease in adults. For every case of bacteremic pneumococcal pneumonia, we estimate that there are at least 3 additional cases of non-bacteremic pneumococcal pneumonia.

Use of complement regulators, CD35, CD46, CD55, and CD59, on leukocytes as markers for diagnosis of viral and bacterial infections

Several complement regulatory proteins exist on self-cells to prevent damage by the serum complement system. In the present study, we aimed to perform quantitative analysis of membrane-bound complement regulators, CR1 (CD35), MCP (CD46), DAF (CD55), and MIRL (CD59), on peripheral blood neutrophils, monocytes, and lymphocytes from healthy controls (n=36) and febrile patients diagnosed with either bacterial (n=21) or viral (n=26) infections. Our results show that: (a) increased CD35 and CD55 levels on neutrophils and monocytes present potent markers of bacterial infection, (b) increased expression of CD46 on monocytes is an indicator of viral infection, and (c) increased CD59 expression on neutrophils and monocytes is a general infection marker. Additionally, CD19-positive B-lymphocytes represent practically the only lymphocyte population capable of expressing CD35. We further developed two novel clinical flow cytometric markers (indices), specifically, clinical mononucleosis (CM)-INDEX (incorporating CD35, CD55, and CD59 expression on lymphocytes) and clinical bacterial infection (CBI)-INDEX (incorporating CD35 and CD55 expression on neutrophils and lymphocytes), for the effective detection of viral mononucleosis and bacterial infection, respectively. In summary, bacterial and viral infections induce different expression patterns of membrane-bound complement regulators in human leukocytes, which may be effectively exploited in clinical differential diagnosis.

A rapid flow cytometric method for distinguishing between febrile bacterial and viral infections

Antibiotic resistance due to the inappropriate use of antimicrobials is one of the most critical public health problems worldwide. A major factor underlying the unnecessary use of antibiotics is the lack of rapid and accurate diagnostic tests. Therefore, we aimed to develop a novel rapid flow cytometric method for distinguishing between febrile bacterial and viral infections. In this prospective comparative study, quantitative flow cytometric analysis of FcγRII/CD32, CR1/CD35, MHC Class I receptor (MHCI), and C5aR/CD88 on human phagocytes was performed in 286 hospitalized febrile patients with suspected infection. After using microbiological and serological detection methods, or clinical diagnosis, 205 patients were identified with either bacterial (n=136) or viral (n=69) infection. Receptor data from patients were compared to those of 50 healthy controls. We developed a flow cytometric marker of local and systemic bacterial infections designated "bacterial infection score (BIS)" incorporating the quantitative analysis of FcγRII/CD32, CR1/CD35, C5aR/CD88 and MHCI on neutrophils and/or monocytes, which displays 91% sensitivity and 92% specificity in distinguishing between microbiologically confirmed bacterial (n=77) and serologically confirmed viral infections (n=61) within 1h. The BIS method was effectively applied to distinguish between bacterial and viral (pandemic H1N1 influenza) pneumonia cases with 96% sensitivity and 92% specificity. We propose that the rapid BIS test can assist physicians in deciding whether antibiotic treatment is necessary, thus reducing unnecessary antimicrobial use.

[Sodium thiosulfate--new hope for the treatment of calciphylaxis]

Calciphylaxis is a rare disease primarily affecting patients dependent on dialysis. It is characterised by small vessel media calcification leading to cutaneous ischemia and necrosis. The mortality rate is high with infection and sepsis being the most common causes of death. Calcium salts, vitamin D and high levels of serum calcium and phosphorus increase the risk of calciphylaxis. Current therapies including restoration of mineral homeostasis, wound care and pain control, are not entirely effective. Sodium thiosulfate, by dissolving calcium deposits, is a novel therapeutic choice for calciphylaxis. It has proved successful also in cases refractory to conventional treatment.

Diagnostic Value of Bronchoalveolar Lavage in Community-acquired Pneumonia in a Routine Setting: A Study on Patients Treated in a Finnish University Hospital

Only a few previous studies have focused on the use or bronchoalveolar lavage (BAL) in patients with community-acquired pneumonia (CAP). Our aim was to evaluate the diagnostic value of BAL in CAP in a routine clinical setting. 71 disease episodes were retrospectively analysed. The patients had undergone BAL for serious or slowly responding pneumonia. All procedures were performed during antimicrobial treatment of the patient. BAL fluid was cultivated for bacteria, fungi, and viruses. In 68 episodes, 1 or several specific polymerase chain reaction tests were performed. Only 1 (1.3%) quantitative bacterial culture was considered diagnostic for CAP, and indicated a change of antimicrobial treatment. The diagnostic yield increased to 9.8% when other methods were used. A respiratory virus was the only aetiology in 3 (6.0%) patients. In slowly responding pneumonia, also hospital-acquired pathogens and malignancies were identified, resulting in a total diagnostic yield of 20.0%. Thus, even when a large array of diagnostic assays was applied, the value of BAL in pretreated patients with CAP was very small, and its therapeutic implications minimal. In a subgroup of slowly responding pneumonia, the procedure was of some usefulness even after commencement of antimicrobial treatment.

Comparison of degranulation of easily mobilizable intracellular granules by human phagocytes in healthy subjects and patients with infectious diseases

The aim of this study was to compare degranulation of easily mobilizable secretory vesicles (SVs) or secretory vesicle-like granules (SVLGs) in neutrophils, monocytes, and eosinophils of healthy controls (n = 60) and febrile patients with microbiologically confirmed or clinically diagnosed bacterial (n = 89) and viral (n = 46) infections. For this purpose, flow cytometric immunophenotyping of isolated phagocytes was performed using monoclonal antibodies against the phagocytosis receptors CR1 (CD35) and CR3 (CD11b) that are predominantly stored in the SVs of resting neutrophils. Similar to neutrophils, monocytes contain easily mobilizable SVLGs that constitute the main intracellular reservoir of CD35 and CD11b. In both neutrophils and monocytes, activation mechanisms leading to degranulation of SV and SVLG appeared dependent on both intra- and extracellular calcium levels. The kinetics of degranulation of SVLGs in control monocytes was significantly faster than that of SVs of control neutrophils. We conclude that phagocytes in patients with bacterial infections can be arranged in order of decreasing magnitude of SV or SVLG degranulation as follows (from left to right): neutrophils > monocytes " eosinophils. However, in viral infections, the corresponding degranulation order is monocytes > neutrophils approximately eosinophils.

CRP/CD11b ratio: a novel parameter for detecting gram-positive sepsis

To commence proper antibiotic treatment in sepsis, timely knowledge of whether the cause of systemic infection is gram-negative (gram(-)) or gram-positive (gram(+)) bacteria in origin would be beneficial for clinicians. In this clinical prospective study, our objective was to develop a method for distinguishing between gram(+) and gram(-) bacterial infection. In gram(-) bacterial infection (n = 21), the average amount of CD11b on neutrophils was significantly higher than in gram(+) bacterial infection (n = 22). On the contrary, serum C-reactive protein (CRP) level was significantly higher in gram(+) than in gram(-) bacterial infection. By dividing the serum CRP value by the amount of CD11b on neutrophils, we derived a novel marker of gram(+) sepsis, CRP/CD11b ratio, which displayed 76% sensitivity and 80% specificity for the detection of gram(+) sepsis (n = 17) among febrile patients with microbiologically confirmed or clinically diagnosed bacterial infection. The detection of gram(+) sepsis is possible after the combination of neutrophil CD11b data and serum CRP level. In conclusion, our findings indicate that the proposed CRP/CD11b ratio test could potentially assist physicians in determining an appropriate antibiotic treatment in patients with severe bacterial infection.

Aetiological diagnosis of community acquired pneumonia: utility of rapid microbiological methods with respect to disease severity

The present study investigated the utility of rapid microbiological methods in the aetiological diagnosis of community acquired pneumonia (CAP) according to the severity of CAP. Between 1999 and 2004, 384 adult patients with CAP were studied prospectively. In addition to standard microbiological methods, PCR and antigen detection techniques were used to identify pathogens. A total of 230 microbial agents in 209 patients were identified, with 134 (58.2%) identified by antigen detection or PCR tests. Of these 134 microbial agents, 95 (70.9%) were identified only by these rapid methods. Streptococcus pneumoniae urinary antigen detection was positive in 24.3% (81/333) of the patients with a diagnostic yield of 38.7% in those with severe pneumonia. Respiratory viral antigen detection was positive in 11.1% (35/314) of the patients with the highest diagnostic yield (20.3%) in patients with severe pneumonia. Mycoplasma pneumoniae PCR was positive in 7.5% (13/174) of the patients, all of whom were low-risk patients. Only 1 case of Chlamydia pneumoniae was identified by PCR. In conclusion, besides yielding the aetiological diagnosis rapidly, new methods add to the total diagnostic yield in CAP. The diagnostic yield of rapid methods differs according to the severity of the pneumonia.

A novel method for distinguishing between dsDNA and ssRNA virus infections

BACKGROUND

To commence proper antiviral treatment, timely knowledge of whether the infection is caused by DNA or RNA virus would be beneficial for the clinician.

OBJECTIVES

Our objective was to develop a method for distinguishing between DNA and RNA virus infections.

STUDY DESIGN

In this prospective study, total and differential count of leukocytes, serum C-reactive protein level, erythrocyte sedimentation rate, and quantitative flow cytometric analysis of FcgammaRI (CD64) on neutrophils and monocytes were obtained from 289 hospitalized febrile patients. After microbiological confirmation, 89 patients (31%) were found to have either bacterial (n=46) or viral (n=43) infection. The patient data was compared to 60 healthy controls.

RESULTS

For the first time ever, it was noticed that in dsDNA virus infections (n=21) the average amount of CD64 on neutrophils was over five-fold compared to ssRNA virus infections (n=22).

CONCLUSIONS

DNA virus score (DNAVS) point, which incorporates quantitative analysis of CD64 on neutrophils and total and differential count of leukocytes, varied between 0 and 8, and displayed 95% sensitivity and 100% specificity in distinguishing between dsDNA and ssRNA virus infections [average (S.D.); DNAVS points: 5.4 (2.5) vs. 0.3 (0.4); p<0.001].

Simultaneous quantitative analysis of FcgammaRI (CD64) expression on neutrophils and monocytes: a new, improved way to detect infections

We performed simultaneous quantitative flow cytometric analysis of neutrophil and monocyte FcgammaRI (CD64) in 289 hospitalized febrile patients. Microbiological evaluation or clinical diagnosis confirmed bacterial (n=89) or viral (n=46) infection in 135 patients. Patient data were compared with data from 60 healthy controls. The average number of FcgammaRI on the surfaces of both neutrophils and monocytes was significantly increased in patients with febrile viral and bacterial infections, compared to healthy controls. Furthermore, we describe a novel marker of febrile infection, designated 'CD64 score point', which incorporates the quantitative analysis of FcgammaRI expressed on both neutrophils and monocytes, with 94% sensitivity and 98% specificity in distinguishing between febrile infections and healthy controls. By contrast, analysis of FcgammaRI expression on neutrophils and monocytes displayed poor sensitivity (73% and 52%) and specificity (65% and 52%) in distinguishing between bacterial and viral infections, and the levels did not differ significantly between systemic (sepsis), local, and clinically diagnosed bacterial infections. In summary, our results clearly show that the increased number of FcgammaRI on neutrophils and monocytes is a useful marker of febrile infection, but cannot be applied for differential diagnosis between bacterial and viral infections or between systemic and local bacterial infections.

Quantitative analysis of complement receptors, CR1 (CD35) and CR3 (CD11b), on neutrophils improves distinction between bacterial and viral infections in febrile patients: Comparison with standard clinical laboratory data

There is an ongoing need for sensitive and specific markers of bacterial infection. In this prospective study, standard clinical laboratory data (neutrophil count, serum C reactive protein level, erythrocyte sedimentation rate) and quantitative flow cytometric analysis of neutrophil complement receptors, CR1 and CR3, were obtained from 289 hospitalized febrile patients. After microbiological confirmation or clinical diagnosis, 135 patients were found to have either bacterial (n = 89) or viral (n = 46) infection. The patient data was compared to 60 healthy controls. In bacterial infections, all measured variables were significantly increased, particularly the average amounts of CR1 and CR3 on neutrophils were over three-fold and two-fold higher, respectively, compared to viral infections and controls. We described a novel marker of local and systemic bacterial infections designated 'clinical infection score (CIS) point', which incorporates quantitative analysis of complement receptors on neutrophils and standard clinical laboratory data. CIS point varied between 0 and 8, and displayed 98% sensitivity and 97% specificity in distinguishing between bacterial and viral infections [average (S.D.); CIS points: 6.2 (1.7) vs. 0.6 (1.0); p < 0.001]. These findings suggest that the proposed CIS-based diagnostic test could potentially assist physicians in deciding whether antibiotic treatment is necessary.

Infective endocarditis in a Finnish teaching hospital: a study on 326 episodes treated during 1980-2004

OBJECTIVES

To evaluate potential changes of infective endocarditis (IE) in patients treated in a Finnish teaching hospital during the past 25 years.

PATIENTS

326 episodes of IE in 303 patients treated during 1980-2004 were evaluated for clinical characteristics and their changes over time.

RESULTS

The mean age of the patients increased with time (from 47.2 to 54.5 years, p = 0.003). Twenty-five (7.7%) episodes were associated with intravenous drug use (IVDU), with a significant increase of these episodes after 1996 (from 0 to 19 (20%), p < 0.001). Viridans streptococci were the most common causative agents of IE during 1980-1994, but after that Staphylococcus aureus was the most common pathogen (p = 0.015). The proportion of IE of the aortic valve decreased during the study (from 30 (49%) to 26 (27%), whereas the proportions of mitral (11 (18%) to 33 (35%) and tricuspid valve IE (0 to 13 (14%) increased correspondingly (p = 0.001). This was mainly due to more patients with IVDU. Chronic dialysis for renal failure as an underlying condition increased over time (from 0 to 7 (7.4%), p = 0.015) but no other predisposing conditions changed. Complications such as neurological manifestations and heart failure did not change in frequency, but the incidence of lung emboli increased (from 0% to 10.5%, p < 0.001); 83% of these emboli occurred in patients with IVDU. The proportion of patients requiring surgical treatment and mortality due to IE did not change.

CONCLUSIONS

During these 25 years, the causative agents, affected valves and complications of IE changed to some degree. These changes were mainly attributed to the increase of IVDU-associated IE. Except for the increase in age, the clinical presentation and outcome in non-addicts remained substantially unchanged.

Spinal epidural lipomatosis caused by corticosteroid treatment in ulcerative colitis

Spinal epidural lipomatosis is the result of deposition of unencapsulated fat in the extradural space of the spinal canal. Most commonly, this rare condition is a complication secondary to corticosteroid treatment. We describe a 49-year-old patient with ulcerative colitis who developed paraparesis due to overgrowth of epidural fat tissue. This is the second patient with ulcerative colitis described in the literature who developed symptomatic epidural lipomatosis secondary to corticosteroid treatment. All internists tending patients with chronic diseases that require corticosteroid treatment should be aware of this rare clinical entity.

Measurement of complement receptor 1 on neutrophils in bacterial and viral pneumonia

Background

A reliable prediction of the causative agent of community-acquired pneumonia (CAP) is not possible based on clinical features. Our aim was to test, whether the measurement of the expression of complement receptors or Fcγ receptors on neutrophils and monocytes would be a useful preliminary test to differentiate between bacterial and viral pneumonia.

Methods

Sixty-eight patients with CAP were studied prospectively. Thirteen patients had pneumococcal pneumonia; 13 patients, influenza A pneumonia; 5 patients, atypical pneumonia, and 37 patients, aetiologically undefined pneumonia. Leukocyte receptor expression was measured within 2 days of hospital admission.

Results

The mean expression of complement receptor 1 (CR1) on neutrophils was significantly higher in the patients with pneumococcal pneumonia than in those with influenza A pneumonia. The mean expression of CR1 was also significantly higher in aetiologically undefined pneumonia than in influenza A pneumonia, but there was no difference between pneumococcal and undefined pneumonia.

Conclusion

Our results suggest that the expression of CR1 is higher in classical bacterial pneumonia than in viral pneumonia. Determination of the expression of CR1 may be of value as an additional rapid tool in the aetiological diagnosis, bacterial or viral infection, of CAP. These results are preliminary and more research is needed to assess the utility of this new method in the diagnostics of pneumonia.

Bronchoalveolar lavage in immunocompromised patients with haematological malignancy--value of new microbiological methods

PURPOSE

To assess the usefulness of new culture-independent microbiological methods to analyse bronchoalveolar lavage (BAL) fluid from haematological patients with clinical pneumonia.

PATIENTS AND METHODS

Results of 135 BALs from 122 disease episodes in 99 patients treated between 1996 and 2002 were retrospectively analysed. Forty-three patients had undergone haematopoietic stem cell transplantation and 56 patients had been treated with conventional chemotherapy for haematological malignancy. In addition to conventional microbiological methods, polymerase chain reaction (PCR) tests for Pneumocystis carinii, cytomegalovirus (CMV), Legionella sp., mycobacterium, Mycoplasma pneumoniae, and Chlamydia pneumoniae and the Aspergillus antigen test were performed.

RESULTS

Three (2.2%) quantitative and four (3.0%) special bacterial cultures gave an aetiological diagnosis. A respiratory virus was isolated in 10 episodes (8.2%). The diagnostic yield increased to 35.6% (48 of 135) by other methods. The P. carinii PCR test was positive in 21 of 24 patients with P. carinii pneumonia, being the only microbiological indication of P. carinii in four cases. The CMV PCR test was positive in 18 patients, but in 14 patients the clinical significance of the finding remained unproven. The Aspergillus antigen test was positive in seven of nine patients with aspergillosis, being the only microbiological indication of Aspergillus in three cases. The result of BAL indicated commencement of specific antimicrobial treatment in 27 episodes (22.1%).

CONCLUSION

The contribution of new culture-independent methods to the total diagnostic yield was of note. Among these methods, the P. carinii PCR and Aspergillus antigen tests proved the most valuable, while the CMV PCR test was not clinically useful.

Parainfluenza virus type 3 infections in a hematology unit

Parainfluenza virus type 3 (PIV3) is associated with a high mortality rate in BMT recipients with lower respiratory tract infections. We describe nine patients with hematological malignancies (five having undergone either allogeneic or autologous stem cell transplantation) identified as having PIV3 infection during a 2-month period in a Hematology Unit. Four patients with infiltrates on chest radiograph received intravenous ribavirin therapy; all survived. The infection was community-acquired in two patients, while nosocomial origin of the disease was evident, or presumed, in the remaining seven. The policy implemented to control the spread of PIV3 was as follows: (1) nasopharyngeal samples for antigen detection were obtained from all patients presenting with respiratory symptoms; (2) all diagnosed (or suspected) PIV3-positive hematological patients were nursed following contact isolation precautions, preferably in the Infectious Diseases Unit; and (3) staff were given further education on hospital hygiene. Our experience shows that it may be possible to avoid mortality for PIV3 lower respiratory tract infection in immunocompromised patients by early commencement of intravenous ribavirin. It is also possible, even without closing the ward, to contain nosocomial spread of PIV3 by implementing systematic nasopharyngeal sampling for rapid diagnostics, and by strict adherence to cohorting and contact isolation precautions.

Increased serum neutral endopeptidase activity in acute renal allograft rejection

Neutral endopeptidase (EC 3.4.24.11; NEP), originally isolated from renal tubular brush border, is a cell surface peptidase identical to the CD10 antigen (or CALLA; common acute lymphoblastic leukemia antigen) in lymphoid cells. We studied the serum NEP levels daily after transplantation (Tx) in 19 renal allograft recipients. The NEP activity was determined with a two-step enzymatic assay utilizing a fluorogenic substrate (Suc-Ala-Ala-Phe-AMC; see text) and related to clinical signs of graft rejection, to signs of immunoactivation in transplant fine-needle aspiration biopsy (FNAB) specimens, to renal function, and to serum levels of C-reactive protein. The serum NEP levels remained normal (peak level 10.3 +/- 1.8 micrograms/l on days 6-9 after Tx, initial level after Tx 7.3 +/- 1.4 micrograms/1 on day 2; mean values +/- SEM) in patients who neither showed clinical signs of rejection nor had findings of immunoactivation in FNAB samples. On the contrary, the serum NEP levels rose clearly in patients developing acute rejection verified clinically and in FNAB samples (peak value 90.4 +/- 18.7 micrograms/l on days 6-9 post-Tx; p < 0.001 compared with patients without sings of immunoactivation) and even in patients having immunoactivation in FNAB without clinical evidence of rejection (108.2 +/- 22.4 micrograms/l, p < 0.001). Serum NEP peak appeared 2-3 days before clinical diagnosis of rejection and a positive findings in FNAB samples. Serum NEP increments did not correlate with changes in serum creatinine, delayed onset of renal excretory function, blood leukocyte count, C-reactive protein level, or infections. Thus, the serum NEP activity was shown to increase after renal allotransplantation associated with early phases of immunoactivation and development of acute graft rejection. Because of the limited number of patients studied, the clinical implications of these preliminary observations for kidney transplant monitoring clearly need confirmation in larger studies.

Inhibition of either angiotensin-converting enzyme or neutral endopeptidase induces both enzymes

Synthesis of angiotensin-converting enzyme is induced during its chronic inhibition. Like angiotensin-converting enzyme, neutral endopeptidase (EC 3.4.24.11) is a plasma membrane peptidase. We studied changes of the two enzymes in lung, kidney and serum in a coronary ligation model of experimental congestive heart failure, and during chronic inhibition of the enzymes. Coronary-ligated rats (n = 19) and sham-operated controls (n = 18) were given SCH 34826 [(S)-N-[N-[1-[[(2,2-dimethyl-1,3-dioxolan-4-yl) methoxy]carbonyl]-2-phenylethyl]-L-phenylalanine]-beta-alanine], a specific neutral endopeptidase inhibitor (n = 13), captopril (n = 12), or vehicle (n = 12) for 4 days, and exsanguinated. Pulmonary angiotensin-converting enzyme was induced both by captopril (52% compared to vehicle) and by SCH 34826 (21%). Serum angiotensin-converting enzyme was induced by captopril (44%). Neutral endopeptidase was induced in lung by captopril (73%), and in kidney by SCH 38426 (32%). Compared to controls, the relative heart weight of rats with heart failure was increased by 29%, and the plasma level of atrial natriuretic peptide elevated by 74%, but enzyme activities were not different. We conclude that, in the rat, separate inhibition of either angiotensin-converting enzyme or neutral endopeptidase induces both enzymes, and that the induction varies in different tissues. Alterations in the substrates of the two enzymes, e.g. in bradykinin, might cause these changes.

Endothelin-1 is expressed and released by a human endothelial hybrid cell line (EA.hy 926)

A permanent vascular endothelial cell line, EA.hy 926, was shown to express endothelin-1 (ET-1) mRNA and to secrete big ET-1 and ET-1 into culture medium. The concentration of both big ET-1 and ET-1 was significantly increased in EA.hy 926 culture medium by phosphoramidon, a metalloproteinase inhibitor, suggesting that phosphoramidon sensitive protease(s) may be responsible for the degradation of ET-1 and big ET-1. EA.hy 926 cells responded to various regulators of ET-1 similarly as primary human vascular endothelial cells. The production of ET-1 was increased by thrombin and decreased by vasodilators such as atrial natriuretic peptide, brain natriuretic peptide and nitroprusside, and by 8-bromo cyclic GMP and papaverine. This continuous human endothelial hybrid cell line could facilitate studies of regulation of ET-1 production in human endothelial cells, which in primary cultures have limited replication potential.

Evaluation of the double antibody-solid phase radioimmunoassay technique in plasma LH and FSH and urinary LH measurements

Double antibody-solid phase (DASP) radioimmunoassay methods for plasma LH and FSH and urinary LH were developed and carefully evaluated as to their reliability and practicability. The peptide hormones were iodinated enzymatically with immobilized lactoperoxidase which resulted in pure and stable products of unchanged immunoreactivity. The sensitivities of these assay methods are 0.02, 0.17 and 0.20 mIU/tube for plasma LH (MRC 68/40) and FSH (MRC 68/39) and urinary LH (IRP-HMG, urinary), respectively. Interassay coefficients of variation obtained over a 6-18 month period were 14.2, 14.7 and 12.8%, respectively. The latter values for plasma LH and FSH assays were obtained from one level pool samples, and the value for urinary LH is the mean of those obtained from two pools of different levels. Plasma reference values for LH and FSH obtained using these methods are about 1.8-2.9 times higher than those cited for other types of radioimmunoassay. However, the values obtained for LH in urine are similar to those reported in the literature. It is suggested that the DASP technique is less influenced by interference from plasma proteins and because of this gives plasma values closer to the true ones. It is concluded that the methods are well suited for use as routine clinical assays in laboratories with a high work load.