Evaluation of new laboratory tests to discriminate bacterial from nonbacterial chronic obstructive pulmonary disease exacerbations.

INTRODUCTIONS: Discriminating bacterial from nonbacterial acute exacerbations of chronic obstructive pulmonary disease (AECOPD) is difficult, causing antibiotics overuse and bacterial resistance. Sputum cultures are of limited use because results take time. In our hospital, only leukocyte concentration and CRP are laboratory parameters evaluated in AECOPD. We evaluated additional tests to discriminate bacterial vs. nonbacterial AECOPD: 5-part leukocyte differentiation (hematology analyzer), leukocyte differentiation using flow cytometry (Leukoflow, Cytodiff), Leuko64 kit, and procalcitonin. METHODS: Retrospectively, patients were classified as bacterial or nonbacterial AECOPD. ROC analyses tested how the additional tests discriminate these groups. RESULTS: Twenty-two AECOPD were classified as bacterial and 23 as nonbacterial. From the additional tests, basophil percentage (Cytodiff) has superior AUC (0.800). At a cutoff resulting in ≥90% sensitivity, neutrophil/lymphocyte ratio (AUC:0.755) and CD4-positive T cells (Leukoflow, AUC:0.747) have the highest specificity (57%). Both neutrophil mean volume and standard deviation (Cell Population Data, DxH800 hematology analyzer) had good combined sensitivity and specificity (AUC:0.846/0.804, 91% sensitivity, 69% specificity). Addition of leukocyte populations and procalcitonin to CRP in regression models (AUC: 0.907/0.876/0.890) increased specificity compared to CRP alone (71% or 73% vs. 39%). CONCLUSION: No additional test has sufficient accuracy on its own to predict bacterial AECOPD. Combining CRP with several parameters from the additional tests may improve this.

Adherence to cardiovascular prevention strategies in patients with rheumatoid arthritis.

OBJECTIVES: Patients with rheumatoid arthritis (RA) have a high risk of cardiovascular disease (CVD). Recent national and international guidelines suggest strict treatment of CVD risk factors in RA. The aim of this study was to evaluate the self-reported adherence to CV prevention strategies in patients with RA. METHOD: RA patients visiting an outpatient clinic for strict CVD risk management received a validated questionnaire to evaluate adherence to CV prevention strategies. Strict treatment targets were defined and lifestyle recommendations were given following a prespecified protocol. CVD risk was assessed using the SCORE algorithm. RESULTS: In total, 111 questionnaires were returned (response rate of 82%). A high 10-year CVD risk (≥ 20%) was present in 53%, but only 3% thought they had an increased CVD risk. A total of 53% of patients reported that they 'follow the doctors' suggestions exactly' and 75% reported finding it 'easy to follow the suggestions'. Of the 69% of patients who were prescribed lipid- and/or blood pressure-lowering drugs, 90% reported taking all prescribed tablets. The advice to follow a diet was given to 42%, of whom 68% said they followed the advised diet. Physical exercise was advised to 67%, of whom 62% said they performed specific physical exercise on at least 3 days a week. The adherence to lifestyle recommendations was not significantly different across the CVD risk groups. CONCLUSIONS: RA patients tend to underestimate their CVD risk. The self-reported adherence of RA patients to CVD risk management was high concerning pharmaceutical interventions and moderate in the case of lifestyle interventions.

Vitamin D3 mediated effects on postprandial leukocyte activation and arterial stiffness in men and women.

Postprandial inflammation is considered to be pro-atherogenic. Vitamin D can reduce inflammation and arterial stiffness. We hypothesized that vitamin D3 improves postprandial arterial elasticity by the modulation of leukocyte activation. Healthy volunteers underwent two oral fat-loading tests (OFLTs). The augmentation index (AIx) and flow cytometric quantification of leukocyte activation markers were measured. After the first OFLT, 100 000 IU of vitamin D3 was administered and a second OFLT was carried out 7 days later. Six men and six women were included. A favorable reduction in AIx was found after vitamin D3 supplementation (P=0.042) in both genders. After vitamin D3, exclusively in women a reduction in the area under the postprandial curve for monocytes CD11b and CD35 by 10.5% (P=0.016) and 12.5% (P=0.04) and neutrophil CD11b by 17.0% (P=0.014) was observed. In conclusion, vitamin D3 probably increased postprandial arterial elasticity in men and women, but reduced postprandial leukocyte activation exclusively in women.

Leukocyte cell population data (volume conductivity scatter) in postprandial leukocyte activation.

INTRODUCTION: Changes in leukocyte cell population data have been reported in various infectious diseases, but little is known in other inflammatory conditions such as the postprandial state. We investigated whether leukocyte cell population data change during postprandial leukocyte activation. METHODS: Healthy volunteers underwent a standardized oral fat loading test (OFLT). Flowcytometric quantitation of leukocyte activation markers CD11b, CD66b, CD35, and CD36, together with leukocyte cell population data from LH750 hematology analyzers were measured fasting and at 4 and 8 h postprandially. RESULTS: Twelve volunteers were included. Postprandial leukocyte activation was confirmed by increased expression of CD11b by monocytes (+11.7%) and neutrophils (+15.0%) and by increased expression of CD66b (+14.7%) and CD35 (+16.6%) by neutrophils at T = 4 h. The mean scatter from neutrophils, reflecting granularity, significantly decreased at T = 4 h (P < 0.05) and returned to baseline at T = 8 h (P-anova 0.048). The mean volume of monocytes increased significantly at T = 4 h (P < 0.001) and returned to baseline at T = 8 h (P-anova 0.0008). At T = 4 h, CD11b expression on neutrophils was associated with a reduction in mean scatter of neutrophils (Pearson's r: -0.677, P = 0.016). CONCLUSION: Postprandial leukocyte activation is accompanied by temporary changes in leukocyte cell population data, similar to changes observed during various infections, but to a lesser extent.

Stem cell factor as a novel diagnostic marker for early malignant germ cells.

Carcinoma in situ (CIS) of the testis is the pre-invasive stage of type II testicular germ cell tumours (TGCTs) of adolescents and adults. These tumours are the most frequently diagnosed cancer in Caucasian adolescents and young adults. In dysgenetic gonads, the precursor of type II GCTs can be either CIS or a lesion known as gonadoblastoma (GB). CIS/GB originates from a primordial germ cell (PGC)/gonocyte, ie an embryonic cell. CIS can be cured by local low-dose irradiation, with limited side effects on hormonal function. Therefore, strategies for early diagnosis of CIS are essential. Various markers are informative to diagnose CIS in adult testis by immunohistochemistry, including c-KIT, PLAP, AP-2gamma, NANOG, and POU5F1 (OCT3/4). OCT3/4 is the most informative and consistent in presence and expression level, resulting in intense nuclear staining. In the case of maturational delay of germ cells, frequently present in gonads of individuals at risk for type II (T)GCTs, use of these markers can result in overdiagnosis of malignant germ cells. This demonstrates the need for a more specific diagnostic marker to distinguish malignant germ cells from germ cells showing maturation delay. Here we report the novel finding that immunohistochemical detection of stem cell factor (SCF), the c-KIT ligand, is informative in this context. This was demonstrated in over 400 cases of normal (fetal, neonatal, infantile, and adult) and pathological gonads, as well as TGCT-derived cell lines, specifically in cases of CIS and GB. Both membrane-bound and soluble SCF were expressed, suggestive of an autocrine loop. SCF immunohistochemistry can be a valuable diagnostic tool, in addition to OCT3/4, to screen for precursor lesions of TGCTs, especially in patients with germ cell maturation delay.

Differential expression of SOX17 and SOX2 in germ cells and stem cells has biological and clinical implications.

Combined action of SOX and POU families of transcription factors plays major roles in embryonic development. In embryonic stem cells, the combination of SOX2 and POU5F1 (OCT3/4) is essential for maintaining the undifferentiated state by activating pluripotency-linked genes, and inhibition of genes involved in differentiation. Besides embryonic stem cells, POU5F1 is also present in early germ cells, primordial germ cells, and gonocytes, where it has a role in suppression of apoptosis. Here we demonstrate that SOX2 is absent in germ cells of human fetal gonads, and as expected carcinoma in situ (CIS), ie the precursor lesion of testicular germ cell tumours of adolescents and adults (TGCTs), and seminoma. Based on genome-wide expression profiling, SOX17 was found to be present, instead of SOX2, in early germ cells and their malignant counterparts, CIS and seminoma. Immunohistochemistry, western blot analysis, and quantitative RT-PCR showed that SOX17 is a suitable marker to distinguish seminoma from embryonal carcinoma, confirmed in representative cell lines. Aberrant SOX2 expression can be present in Sertoli cells when associated with CIS, which can be misdiagnosed as embryonal carcinoma. In conclusion, this study demonstrates the absence of SOX2 in human embryonic and malignant germ cells, which express SOX17 in conjunction with POU5F1. This finding has both diagnostic and developmental biological implications. It allows the identification of seminoma-like cells from embryonal carcinoma based on a positive marker and might be the explanation for the different function of POU5F1 in normal and malignant germ cells versus embryonic stem cells.

Granulocyte colony-stimulating factor and its receptor in normal hematopoietic cell development and myeloid disease.

Hematopoiesis, the process of blood cell formation, is orchestrated by cytokines and growth factors that stimulate the expansion of different progenitor cell subsets and regulate their survival and differentiation into mature blood cells. Granulocyte colony-stimulating factor (G-CSF) is the major hematopoietic growth factor involved in the control of neutrophil development. G-CSF is now applied on a routine basis in the clinic for treatment of congenital and acquired neutropenias. G-CSF activates a receptor of the hematopoietin receptor superfamily, the G-CSF receptor (G-CSF-R), which subsequently triggers multiple signaling mechanisms. Here we review how these mechanisms contribute to the specific responses of hematopoietic cells to G-CSF and how perturbations in the function of the G-CSF-R are implicated in various types of myeloid disease.