Fever of unknown origin in cancer patients

A novel method for simultaneous detection of hematological tumors and infectious pathogens by metagenomic next generation sequencing of plasma

BACKGROUND

Metagenomic next-generation sequencing (mNGS) is valuable for pathogen identification; however, distinguishing between infectious diseases and conditions with potentially similar clinical manifestations, including malignant tumors, is challenging. Therefore, we developed a method for simultaneous detection of infectious pathogens and cancer in blood samples.

METHODS

Plasma samples (n = 244) were collected from 150 and 94 patients with infections and hematological malignancies, respectively, and analyzed by mNGS for pathogen detection, alongside human tumor chromosomal copy number variation (CNV) analysis (≥5Mbp or 10Mbp CNV region). Further, an evaluation set, comprising 87 plasma samples, was analyzed by mNGS and human CNV analysis, to validate the feasibility of the method.

RESULTS

Among 94 patients with hematological malignancy, sensitivity values of CNV detection for tumor diagnosis were 69.15 % and 32.98 % for CNV region 5Mbp and 10Mbp, respectively, with corresponding specificities of 92.62 % and 100 % in the infection group. Area under the ROC curve (AUC) values for 5Mbp and 10Mbp region were 0.825 and 0.665, respectively, which was a significant difference of 0.160 (95 % CI: 0.110-0.210; p < 0.001), highlighting the superiority of 5Mbp output region data. Six patients with high-risk CNV results were identified in the validation study: three with history of tumor treatment, two eventually newly-diagnosed with hematological malignancies, and one with indeterminate final diagnosis.

CONCLUSIONS

Concurrent CNV analysis alongside mNGS for infection diagnosis is promising for detecting malignant tumors. We recommend adopting a CNV region of 10Mbp over 5Mbp for our model, because of the lower false-positive rate (FPR).

Current State of Knowledge on the Definition, Pathophysiology, Etiology, Outcomes, and Management of Fever in the Intensive Care Unit

Fever-an elevated body temperature-is a prominent feature of a wide range of disease conditions and is a common finding in intensive care, affecting up to 70% of patients in the intensive care unit (ICU). The causes of fever in the ICU are multifactorial, and it can be due to a number of infective and noninfective etiologies. The production of fever represents a complex physiological, adaptive host response that is beneficial for host defense and survival but can be maladaptive and harmful if left unabated. Despite any cause, fever is associated with a wide range of cellular, local, and systemic effects, including multiorgan dysfunction, systemic inflammation, poor neurological recovery, and an increased risk of mortality. This narrative review presents the current state-of-the-art knowledge on the definition, pathophysiology, etiology, and outcomes of fever in the ICU and highlights evidence-based findings regarding the management of fever in the intensive care setting.

Fever of Unknown Origin and Multidrug Resistant Organism Colonization in AML Patients

Background

Colonization by multidrug-resistant organisms (MDRO) is a frequent complication in hematologic departments, which puts patients at risk of life-threatening bacterial sepsis. Fever of unknown origin (FUO) is a condition related to the delivery of chemotherapy in hematologic malignancies, in which the use of antibiotics is debated. The incidence, risk factors, and influence on the outcome of these conditions in patients with acute myeloid leukemia (AML) are not clearly defined.

Methods

We retrospectively analyzed 132 consecutive admissions of non-promyelocytic AML patients at the Hematology Unit of the University Tor Vergata in Rome between June 2019 and February 2022. MDRO swab-based screening was performed in all patients on the day of admission and once weekly after that. FUO was defined as fever with no evidence of infection.

Results

Of 132 consecutive hospitalizations (69 AML patients), MDRO colonization was observed in 35 cases (26%) and resulted independently related to a previous MDRO colonization (p=0.001) and length of hospitalization (p=0.03). The colonization persistence rate in subsequent admissions was 64%. MDRO-related bloodstream infection was observed in 8 patients (23%) and correlated with grade III/IV mucositis (p=0.008) and length of hospitalization (p=0.02). FUO occurred in 68 cases (51%) and correlated with an absolute neutrophilic count <500μ/L at admission (0.04).

Conclusion

In our experience, MDRO colonization is a frequent and difficult-to-eradicate condition that can arise at all stages of treatment. Prompt discharge of patients as soon as clinical conditions allow could limit the spread of MDRO. In addition, the appropriate use of antibiotics, especially in the case of FUO, and the contraction of hospitalization length, when feasible, are measures to tackle the further spread of MDRO.

Diagnostic value of FDG-PET/CT in fever of unknown origin

Background

Fever of unknown origin (FUO) is a challenging clinical problem in medicine that needs collaboration of various diagnostic techniques to establish the accurate diagnosis. We evaluated the diagnostic performance of 18F-FDG PET/CT in patients who presented themselves with FUO. Our study included 40 patients with FUO who underwent PET/CT examination and their results were compared to the results of laboratory, histopathological, microbiological investigations and/or response to therapy.

Results

The final diagnosis included malignancy in 20 patients (50%), infectious causes in 7 patients (17.5%) and non-infectious inflammatory causes in 6 patients (15%). Fever resolved without diagnosis in 4 patients (10%), while no definite diagnosis was reached in 3 patients (7%). PET/CT successfully contributed to diagnosis of 35 out of 40 patients with diagnostic accuracy of 87.5%. The sensitivity, specificity, positive predictive value and negative predictive value of PET/CT in our study were 93.5%, 66.7%, 90.6% and 75%, respectively.

Conclusion

PET/CT is a useful tool to investigate and diagnose the cause of FUO. It provides information that can guide the treatment strategy of the patients.

Optimal use of the FDG-PET/CT in the diagnostic process of fever of unknown origin (FUO): a comprehensive review

Numerous studies have clarified the usefulness of ¹⁸F-fluorodeoxyglucose (FDG)-PET/CT (positron emission tomography) for diagnosing the cause of fever of unknown origin (FUO). Various types of disease can cause FUO, but the cause remains unknown in a certain proportion of FUO, even when the advanced diagnostic methodologies are used. FDG-PET/CT is regarded as a second-line modality in the diagnostic process of FUO, and its potential to identify the cause of FUO will be maximized when the appropriate clinical considerations are understood. Accordingly, this review presents basic knowledge regarding FUO, and reports the current status of FDG-PET/CT applied to diagnosing the cause of FUO, including diagnostic performance, test protocols, possible factors influencing the diagnostic result, outcomes, and cost-effectiveness. This knowledge will enable effective future use of FDG-PET/CT to improve outcomes in patients with FUO.

Application of Machine Learning for the Prediction of Etiological Types of Classic Fever of Unknown Origin

Background: The etiology of fever of unknown origin (FUO) is complex and remains a major challenge for clinicians. This study aims to investigate the distribution of the etiology of classic FUO and the differences in clinical indicators in patients with different etiologies of classic FUO and to establish a machine learning (ML) model based on clinical data. Methods: The clinical data and final diagnosis results of 527 patients with classic FUO admitted to 7 medical institutions in Chongqing from January 2012 to August 2021 and who met the classic FUO diagnostic criteria were collected. Three hundred seventy-three patients with final diagnosis were divided into 4 groups according to 4 different etiological types of classical FUO, and statistical analysis was carried out to screen out the indicators with statistical differences under different etiological types. On the basis of these indicators, five kinds of ML models, i.e., random forest (RF), support vector machine (SVM), Light Gradient Boosting Machine (LightGBM), artificial neural network (ANN), and naive Bayes (NB) models, were used to evaluate all datasets using 5-fold cross-validation, and the performance of the models were evaluated using micro-F1 scores. Results: The 373 patients were divided into the infectious disease group (n = 277), non-infectious inflammatory disease group (n = 51), neoplastic disease group (n = 31), and other diseases group (n = 14) according to 4 different etiological types. Another 154 patients were classified as undetermined group because the cause of fever was still unclear at discharge. There were significant differences in gender, age, and 18 other indicators among the four groups of patients with classic FUO with different etiological types (P < 0.05). The micro-F1 score for LightGBM was 75.8%, which was higher than that for the other four ML models, and the LightGBM prediction model had the best performance. Conclusions: Infectious diseases are still the main etiological type of classic FUO. Based on 18 statistically significant clinical indicators such as gender and age, we constructed and evaluated five ML models. LightGBM model has a good effect on predicting the etiological type of classic FUO, which will play a good auxiliary decision-making function.

The rise in cases of mucormycosis, candidiasis and aspergillosis amidst COVID19

The Coronavirus outbreak globally has changed the medical system and also led to a shortage of medical facilities in both developing and underdeveloped countries. The COVID19 disease, being novel in nature along with high infectivity and frequent mutational rate, has been termed to be fatal across the globe. The advent of infection by SARS-CoV-2 has brought a myriad of secondary complications and comorbidities resulting in additional challenges to the health care system induced by novel therapeutic procedures. The emerging variant with respect to the Indian subcontinent and the associated genetic mutations have worsened the situation at hand. Proper clinical management along with epidemiological studies and clinical presentations in scientific studies and trials is necessary in order to combat the simultaneous waves of emerging strains. This article summarizes three of the major fungal outbreaks in India namely mucormycosis, candidiasis and aspergillosis, and elaborates their subtypes, pathogenesis, symptoms and treatment and detection techniques. A detail of future therapeutics under consideration are also elaborated along with a general hypothesis on how COVID19 is related to immunological advances leading to major widespread fungal infection in the country. The factors that contribute in promoting virus proliferation and invasive fungal infections include cell-mediated immunity, associated immunocompromised conditions and treatment protocols that slows down immune mechanisms. To better comprehend a fungal or bacterial outbreak, it is very important to conduct audits mediated through multicenter national and state research teams for recognizing patterns and studying current cases of fungal infection in both healthy and comorbid groups of COVID19 patients.

Undifferentiated Pleomorphic Sarcoma with Neoplastic Fever: A Retrospective Study

Background

Although the annual incidence of undifferentiated pleomorphic sarcoma (UPS) is extremely low, it can be subdivided into different subtypes. UPS with fever of unknown origin (also known as neoplastic fever) is a specific subtype of UPS, which shows certain clinical features that differentiate it from other UPS subtypes. However, no studies have focused on this rare UPS subtype. This study retrospectively analyzed the clinical data of patients with UPS to provide a reference for the diagnosis and treatment of UPS with neoplastic fever.

Methods

This study included patients with UPS who were diagnosed and treated between June 2012 and June 2018. We examined whether these patients had a history of neoplastic fever. The characteristics of patients with UPS with neoplastic fever were summarized and analyzed.

Results

We reviewed the medical records of 183 patients with UPS. Seven (3.83%) of these patients had neoplastic fever. In patients with UPS with neoplastic fever, the primary lesions were located in the extremities and across the muscle space. In these patients, magnetic resonance imaging showed necrosis within the tumor body and extensive soft tissue edema around the tumor body. Patients with UPS with neoplastic fever had a lower metastasis rate (14.29% vs 44.94%) and a higher 3-year survival rate (85.71% vs 59.55%) than those without neoplastic fever.

Conclusion

UPS with neoplastic fever is characterized by intratumoral necrosis and extensive edema of the surrounding soft tissues. Patients with UPS with neoplastic fever may have a better prognosis than those without neoplastic fever.

Antibody-guided in vivo imaging of Aspergillus fumigatus lung infections during antifungal azole treatment

Invasive pulmonary aspergillosis (IPA) is a life-threatening lung disease of immunocompromised humans, caused by the opportunistic fungal pathogen Aspergillus fumigatus. Inadequacies in current diagnostic procedures mean that early diagnosis of the disease, critical to patient survival, remains a major clinical challenge, and is leading to the empiric use of antifungal drugs and emergence of azole resistance. A non-invasive procedure that allows both unambiguous detection of IPA and its response to azole treatment is therefore needed. Here, we show that a humanised Aspergillus-specific monoclonal antibody, dual labelled with a radionuclide and fluorophore, can be used in immunoPET/MRI in vivo in a neutropenic mouse model and 3D light sheet fluorescence microscopy ex vivo in the infected mouse lungs to quantify early A. fumigatus lung infections and to monitor the efficacy of azole therapy. Our antibody-guided approach reveals that early drug intervention is critical to prevent complete invasion of the lungs by the fungus, and demonstrates the power of molecular imaging as a non-invasive procedure for tracking IPA in vivo.

Invasive pulmonary aspergillosis is a life-threatening fungal lung disease devoid of specific rapid diagnosis and with limited therapeutic options. Here, the authors show how state-of-the-art imaging approaches can enable specific diagnosis and therapy monitoring of this infection.

State of the art of 18F-FDG PET/CT application in inflammation and infection: a guide for image acquisition and interpretation

AIM

The diagnosis, severity and extent of a sterile inflammation or a septic infection could be challenging since there is not one single test able to achieve an accurate diagnosis. The clinical use of 18F-fluorodeoxyglucose ([¹⁸F]FDG) positron emission tomography/computed tomography (PET/CT) imaging in the assessment of inflammation and infection is increasing worldwide. The purpose of this paper is to achieve an Italian consensus document on [¹⁸F]FDG PET/CT or PET/MRI in inflammatory and infectious diseases, such as osteomyelitis (OM), prosthetic joint infections (PJI), infective endocarditis (IE), prosthetic valve endocarditis (PVE), cardiac implantable electronic device infections (CIEDI), systemic and cardiac sarcoidosis (SS/CS), diabetic foot (DF), fungal infections (FI), tuberculosis (TBC), fever and inflammation of unknown origin (FUO/IUO), pediatric infections (PI), inflammatory bowel diseases (IBD), spine infections (SI), vascular graft infections (VGI), large vessel vasculitis (LVV), retroperitoneal fibrosis (RF) and COVID-19 infections.

METHODS

In September 2020, the inflammatory and infectious diseases focus group (IIFG) of the Italian Association of Nuclear Medicine (AIMN) proposed to realize a procedural paper about the clinical applications of [¹⁸F]FDG PET/CT or PET/MRI in inflammatory and infectious diseases. The project was carried out thanks to the collaboration of 13 Italian nuclear medicine centers, with a consolidate experience in this field. With the endorsement of AIMN, IIFG contacted each center, and the pediatric diseases focus group (PDFC). IIFG provided for each team involved, a draft with essential information regarding the execution of [¹⁸F]FDG PET/CT or PET/MRI scan (i.e., indications, patient preparation, standard or specific acquisition modalities, interpretation criteria, reporting methods, pitfalls and artifacts), by limiting the literature research to the last 20 years. Moreover, some clinical cases were required from each center, to underline the teaching points. Time for the collection of each report was from October to December 2020.

RESULTS

Overall, we summarized 291 scientific papers and guidelines published between 1998 and 2021. Papers were divided in several sub-topics and summarized in the following paragraphs: clinical indications, image interpretation criteria, future perspectivess and new trends (for each single disease), while patient preparation, image acquisition, possible pitfalls and reporting modalities were described afterwards. Moreover, a specific section was dedicated to pediatric and PET/MRI indications. A collection of images was described for each indication.

CONCLUSIONS

Currently, [¹⁸F]FDG PET/CT in oncology is globally accepted and standardized in main diagnostic algorithms for neoplasms. In recent years, the ever-closer collaboration among different European associations has tried to overcome the absence of a standardization also in the field of inflammation and infections. The collaboration of several nuclear medicine centers with a long experience in this field, as well as among different AIMN focus groups represents a further attempt in this direction. We hope that this document will be the basis for a "common nuclear physicians' language" throughout all the country.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s40336-021-00445-w.

Advances in the In Vivo Molecular Imaging of Invasive Aspergillosis

Invasive pulmonary aspergillosis (IPA) is a life-threatening infection of immunocompromised patients with Aspergillus fumigatus, a ubiquitous environmental mould. While there are numerous functioning antifungal therapies, their high cost, substantial side effects and fear of overt resistance development preclude permanent prophylactic medication of risk-patients. Hence, a fast and definitive diagnosis of IPA is desirable, to quickly identify those patients that really require aggressive antimycotic treatment and to follow the course of the therapeutic intervention. However, despite decades of research into this issue, such a diagnostic procedure is still not available. Here, we discuss the array of currently available methods for IPA detection and their limits. We then show that molecular imaging using positron emission tomography (PET) combined with morphological computed tomography or magnetic imaging is highly promising to become a future non-invasive approach for IPA diagnosis and therapy monitoring, albeit still requiring thorough validation and relying on further acceptance and dissemination of the approach. Thereby, our approach using the A. fumigatus-specific humanized monoclonal antibody hJF5 labelled with ⁶⁴Cu as PET-tracer has proven highly effective in pre-clinical models and hence bears high potential for human application.

Fever of unknown origin in special groups

Fever of undetermined origin (FUO) is a challenging entity with a striking presence in hospitals around the world. It is defined as temperature ≥ 37.8 ° C on several occasions, lasting ≥ three weeks, in the absence of diagnosis after three days of hospital investigation or 3 outpatient visits. The main etiologies are infectious, neoplastic, and non-infectious inflammatory diseases. The diagnosis is based on the detailed clinical history and physical examination of these patients, in order to direct the specific complementary tests to be performed in each case. The initial diagnostic approach of the FUO patient should include non-specific complementary exams. Empirical therapy is not recommended (with few exceptions) in patients with prolonged fever, as it may disguise and delay the diagnosis and conduct to treat the specific etiology. The prognosis encompasses mortality of 12-35%, varying according to the baseline etiology.

Fever of unknown origin - a literature review

Fever of undetermined origin (FUO) is a challenging entity with a striking presence in hospitals around the world and can be associated with a myriad of differential diagnoses. It is defined as axillary temperature ≥ 37.8 ° C on several occasions, lasting ≥ three weeks, in the absence of diagnosis after three days of hospital investigation or three outpatient visits. The main etiologies are: infectious, neoplastic, and rheumatic. The diagnosis is based on the detailed clinical history and physical examination of these patients, in order to direct the specific complementary tests to be performed in each case. Empirical therapy is not recommended (with few exceptions) in patients with prolonged fever, as it may disguise and delay the diagnosis and conduct to treat the specific etiology. The prognosis encompasses mortality of 12% - 35%, varying according to the underlying etiology. In this sense, the objective of this study is to review the main topics about fever of undetermined origin, bringing historical and scientific aspects, national and international.

Retrospective analysis of cancer patients admitted to a tertiary centre with suspected neutropenic sepsis: Are C-reactive protein and neutrophil count useful prognostic biomarkers?

Historically, neutropenic sepsis has been associated with high mortality rates. However, there has been limited research into cancer patients admitted with suspected sepsis who are found to be non-neutropenic. C-reactive protein has been shown to be raised in cancer patients for reasons other than infection and there have been limited studies to look as its utility as a prognostic biomarker in suspected sepsis in this population. This study looked at 749 patients admitted to a tertiary cancer centre between January 2015 and February 2016 with suspected sepsis. The neutrophil count and C-reactive protein level was taken in all these patients on admission and at 72 h and compared to the primary outcome of 30-day all-cause mortality rates and hospital length of stay. There were 49 patients who died within 30 days (6.5%). Patients who died were found to have both higher neutrophil counts and C-reactive protein level on admission and at 72 h compared to survivors. Prolonged grade 4 neutropenia was shown to have higher mortality rates. There was only weak correlation between either neutrophil counts or C-reactive protein level and length of hospital stay. This study suggests that higher C-reactive protein level and neutrophil counts and prolonged grade 4 neutropenia are associated with higher mortality rates in cancer patients admitted with suspected sepsis and have utility as prognostic biomarkers in this population.

Acute Oncology Care: A narrative review of the acute management of neutropenic sepsis and immune-related toxicities of checkpoint inhibitors

Cancer care has become increasingly specialized and advances in therapy have resulted in a larger number of patients receiving care. There has been a significant increase in the number of patients presenting with cancer related emergencies including treatment toxicities and those directly related to the malignancy. Suspected neutropenic sepsis is an acute medical emergency and empirical antibiotic therapy should be administered immediately. The goal of empirical therapy is to cover the most likely pathogens that will cause life-threatening infections in neutropenic patients. Patients with febrile neutropenia are a heterogeneous group with only a minority of treated patients developing significant medical complications. Outpatient management of low risk febrile neutropenia patients identified by the MASCC score is a safe and effective strategy. Immunotherapy with "checkpoint inhibitors" has significantly improved outcomes for patients with metastatic melanoma and evidence of benefit in a wide range of malignancies is developing. Despite these clinical benefits a number of immune related adverse events have been recognised which can affect virtually all organ systems and are potentially fatal. The timing of the onset of the adverse events is dependent on the organ system affected and unlike anti-neoplastic therapy can be delayed significantly after initiation or completion of therapy. The field of Acute Oncology is changing rapidly. Alongside, the traditional challenge of neutropenic sepsis there are many emerging toxicities. Further research into the optimal management, strategies and pathways of acutely unwell patients with cancer is required.

Granulocyte colony-stimulating factor-producing hepatocellular carcinoma with abrupt changes

Granulocyte colony-stimulating factor (G-CSF)-producing tumor is one of the rare types of cancer clinically characterized by an elevated fever and white blood cell (WBC) increment. Although G-CSF producing tumors have been reported in several types of cancer including those of the lungs, cervix and bladder, G-CSF producing hepatocellular carcinoma is extremely rare. Here, we report the case of a rapidly growing and poorly differentiated hepatocellular carcinoma producing G-CSF. The patient showed symptoms of continuous high fever, stomach pain and cough, and high serum WBC counts, C-reactive protein (CRP) and G-CSF levels were found in laboratory tests. After a radical hepatectomy, the patient completely recovered from the above symptoms and inflammatory state. The serum levels of G-CSF were reduced to normal levels after radical surgery. An immunohistochemical analysis revealed the overexpression of G-CSF in the cytoplasm of certain hepatocellular carcinoma (HCC) cell. The patient’s serum WBC, CRP and G-CSF levels remained within normal levels in the six months after surgery without recurrence. This is the 9^th case report of G-CSF producing hepatocellular carcinoma in English literature. We review the clinical characteristics of the G-CSF producing HCC and discuss a possible treatment strategy.