Utility of Differential White Cell Count and Cell Population Data for Ruling Out COVID-19 Infection in Patients With Community-Acquired Pneumonia

INTRODUCTION

The main aim of this study was to assess the utility of differential white cell count and cell population data (CPD) for the detection of COVID-19 in patients admitted for community-acquired pneumonia (CAP) of different etiologies.

METHODS

This was a multicenter, observational, prospective study of adults aged ≥18 years admitted to three teaching hospitals in Spain from November 2019 to November 2021 with a diagnosis of CAP. At baseline, a Sysmex XN-20 analyzer was used to obtain detailed information related to the activation status and functional activity of white cells.

RESULTS

The sample was split into derivation and validation cohorts of 1065 and 717 patients, respectively. In the derivation cohort, COVID-19 was confirmed in 791 patients and ruled out in 274 patients, with mean ages of 62.13 (14.37) and 65.42 (16.62) years, respectively (p<0.001). There were significant differences in all CPD parameters except MO-Y. The multivariate prediction model showed that lower NE-X, NE-WY, LY-Z, LY-WY, MO-WX, MO-WY, and MO-Z values and neutrophil-to-lymphocyte ratio were related to COVID-19 etiology with an AUC of 0.819 (0.790, 0.846). No significant differences were found comparing this model to another including biomarkers (p=0.18).

CONCLUSIONS

Abnormalities in white blood cell morphology based on a few cell population data values as well as NLR were able to accurately identify COVID-19 etiology. Moreover, systemic inflammation biomarkers currently used were unable to improve the predictive ability. We conclude that new peripheral blood biomarkers can help determine the etiology of CAP fast and inexpensively.

Correction to: Impact of reducing the duration of antibiotic treatment on the long-term prognosis of community acquired pneumonia

An amendment to this paper has been published and can be accessed via the original article.

Impact of reducing the duration of antibiotic treatment on the long-term prognosis of community acquired pneumonia

Background

The optimal duration of antibiotic treatment for community-acquired pneumonia (CAP) is not well established. The aim of this study was to assess the impact of reducing the duration of antibiotic treatment on long-term prognosis in patients hospitalized with CAP.

Methods

This was a multicenter study assessing complications developed during 1 year of patients previously hospitalized with CAP who had been included in a randomized clinical trial concerning the duration of antibiotic treatment. Mortality at 90 days, at 180 days and at 1 year was analyzed, as well as new admissions and cardiovascular complications. A subanalysis was carried out in one of the hospitals by measuring C-reactive protein (CRP), procalcitonin (PCT) and proadrenomedullin (proADM) at admission, at day 5 and at day 30.

Results

A total of 312 patients were included, 150 in the control group and 162 in the intervention group. Ninety day, 180 day and 1-year mortality in the per-protocol analysis were 8 (2.57%), 10 (3.22%) and 14 (4.50%), respectively. There were no significant differences between both groups in terms of 1-year mortality (p = 0.94), new admissions (p = 0.84) or cardiovascular events (p = 0.33). No differences were observed between biomarker level differences from day 5 to day 30 (CRP p = 0.29; PCT p = 0.44; proADM p = 0.52).

Conclusions

Reducing antibiotic treatment in hospitalized patients with CAP based on clinical stability criteria is safe, without leading to a greater number of long-term complications.

Mapping the malaria parasite druggable genome by using in vitro evolution and chemogenomics

Chemogenetic characterization through in vitro evolution combined with whole-genome analysis can identify antimalarial drug targets and drug-resistance genes.We performed a genome analysis of 262 Plasmodium falciparum parasites resistant to 37 diverse compounds.We found 159 gene amplifications and 148 nonsynonymous changes in 83 genes associated with drug-resistance acquisition, where gene amplifications contributed to one-third of resistance acquisition events. Beyond confirming previously identified multidrug-resistance mechanisms, we discovered hitherto unrecognized drug target–inhibitor pairs, including thymidylate synthase and a benzoquinazolinone, farnesyltransferase and a pyrimidinedione, and a dipeptidylpeptidase and an arylurea.This exploration of the P. falciparum resistome and druggable genome will likely guide drug discovery and structural biology efforts, while also advancing our understanding of resistance mechanisms available to the malaria parasite.

Duration of Antibiotic Treatment in Community-Acquired Pneumonia: A Multicenter Randomized Clinical Trial

IMPORTANCE

The optimal duration of antibiotic treatment for community-acquired pneumonia (CAP) has not been well established.

OBJECTIVE

To validate Infectious Diseases Society of America/American Thoracic Society guidelines for duration of antibiotic treatment in hospitalized patients with CAP.

DESIGN, SETTING, AND PARTICIPANTS

This study was a multicenter, noninferiority randomized clinical trial performed at 4 teaching hospitals in Spain from January 1, 2012, through August 31, 2013. A total of 312 hospitalized patients diagnosed as having CAP were studied. Data analysis was performed from January 1, 2014, through February 28, 2015.

INTERVENTIONS

Patients were randomized at day 5 to an intervention or control group. Those in the intervention group were treated with antibiotics for a minimum of 5 days, and the antibiotic treatment was stopped at this point if their body temperature was 37.8°C or less for 48 hours and they had no more than 1 CAP-associated sign of clinical instability. Duration of antibiotic treatment in the control group was determined by physicians.

MAIN OUTCOMES AND MEASURES

Clinical success rate at days 10 and 30 since admission and CAP-related symptoms at days 5 and 10 measured with the 18-item CAP symptom questionnaire score range, 0-90; higher scores indicate more severe symptoms.

RESULTS

Of the 312 patients included, 150 and 162 were randomized to the control and intervention groups, respectively. The mean (SD) age of the patients was 66.2 (17.9) years and 64.7 (18.7) years in the control and intervention groups, respectively. There were 95 men (63.3%) and 55 women (36.7%) in the control group and 101 men (62.3%) and 61 women (37.7%) in the intervention group. In the intent-to-treat analysis, clinical success was 48.6% (71 of 150) in the control group and 56.3% (90 of 162) in the intervention group at day 10 (P = .18) and 88.6% (132 of 150) in the control group and 91.9% (147 of 162) in the intervention group at day 30 (P = .33). The mean (SD) CAP symptom questionnaire scores were 24.7 (11.4) vs 27.2 (12.5) at day 5 (P = .10) and 18.6 (9.0) vs 17.9 (7.6) at day 10 (P = .69). In the per-protocol analysis, clinical success was 50.4% (67 of 137) in the control group and 59.7% (86 of 146) in the intervention group at day 10 (P = .12) and 92.7% (126 of 137) in the control group and 94.4% (136 of 146) in the intervention group at day 30 (P = .54). The mean (SD) CAP symptom questionnaire scores were 24.3 (11.4) vs 26.6 (12.1) at day 5 (P = .16) and 18.1 (8.5) vs 17.6 (7.4) at day 10 (P = .81).

CONCLUSIONS AND RELEVANCE

The Infectious Diseases Society of America/American Thoracic Society recommendations for duration of antibiotic treatment based on clinical stability criteria can be safely implemented in hospitalized patients with CAP.

TRIAL REGISTRATION

clinicaltrialsregister.eu Identifier: 2011-001067-51.

[Diagnosis of anaerobic infection of the pleural fluid using gas-liquid chromatography]

BACKGROUND

An assessment of the efficacy of the detection of volatile and non-volatile fatty acids that are produced by microorganisms aimed at the possible diagnosis of pleural empyema.

METHODS

106 pleural fluids were examined by gas-liquid chromatography in contrast to conventional aerobic and anaerobic cultures. The sample previously prepared (1 microliter) was injected in an Hewlett-Packard 5890 chromatograph, that was equipped with a fused silica capillary column and a flame ionization detector.

RESULTS

Growth of aerobic or anaerobic microorganisms was obtained in 13 (12.3%) of the samples, and volatile or non-volatile fatty acids were detected in all of them (sensitivity = 1). No growth was obtained in the 93 samples, but volatile or non-volatile fatty acids were detected in 64 (68.8%) of them (specificity = 0.31). A positive predictive value of 0.17 and a negative predictive value of 1 were obtained. Growth of anaerobic microorganisms was obtained in 9 samples (8.5%) and volatile fatty acids were detected in all of them (sensitivity = 1). Anaerobic microorganisms did not grow in 97 samples, however volatile fatty acids were detected in 2 (2.1%) of them. A positive predictive value of 0.82 and a negative of 1 were obtained.

CONCLUSIONS

Referring to pleural fluid samples, the detection of volatile and non-volatile fatty acids by gas-liquid chromatography is a highly sensitive method, that may be used to quickly reject negative samples in about 30 mins. Furthermore, when anaerobic microorganisms exist, the high specificity of gas-liquid chromatography will make it possible to confirm their presence in the sample, mainly if there is a clinical suspect of anaerobic infection. Thus, the utilization of this sensitive method may also change the therapeutic behaviour.

[Chronic granulomatous disease and pulmonary nocardiosis]

A 19-years-old male was admitted for left bilobar pneumonia. All microbiologic studies in blood and in several samples obtained by bronchoscopy were negative. The patient worsened progressively despite antibiotherapy of a wide spectrum. A fine needle transparietal puncture was performed. The cultures of the sample were positive for Nocardia asteroides, a positive catalase germ. Immunologic studies initiated after this time showed negative tetrazolium nitroblue test, the results of which led to the diagnosis of chronic granulomatous disease. This disease is very infrequent and the polymorphonuclear leukocytes are genetically incapable of producing peroxides whose absence impedes lysis of the positive phagocytic catalase germs with which a histologic reaction is produced in the form of granulomas from which the name of the disease is derived.