New parameters available on Sysmex XE-5000 hematology analyzers contribute to differentiating dengue from leptospirosis and enteric fever

Risk factors associated with day-30 mortality in patients over 60 years old admitted in ICU for severe COVID-19: the Senior-COVID-Rea Multicentre Survey protocol

INTRODUCTION

With the spread of COVID-19 epidemic, health plans must be adapted continuously. There is an urgent need to define the best care courses of patients with COVID-19, especially in intensive care units (ICUs), according to their individualised benefit/risk ratio. Since older age is associated with poorer short-term and long-term outcomes, prediction models are needed, that may assist clinicians in their ICU admission decision. Senior-COVID-Rea was designed to evaluate, in patients over 60 years old admitted in ICU for severe COVID-19 disease, the impact of age and geriatric and paraclinical parameters on their mortality 30 days after ICU admission.

METHODS AND ANALYSIS

This is a multicentre survey protocol to be conducted in seven hospitals of the Auvergne-Rhône-Alpes region, France. All patients over 60 years old admitted in ICU for severe COVID-19 infection (or their legally acceptable representative) will be proposed to enter the study and to fill in a questionnaire regarding their functional and nutritional parameters 1 month before COVID-19 infection. Paraclinical parameters at ICU admission will be collected: lymphocytes and neutrophils counts, high-fluorescent lymphoid cells and immature granulocytes percentages (Sysmex data), D-dimers, C-reactive protein, lactate dehydrogenase (LDH), creatinine, CT scan for lung extension rate as well as clinical resuscitation scores, and the delay between the first signs of infection and ICU admission. The primary outcome will be the overall survival at day 30 post-ICU admission. The analysis of factors predicting mortality at day 30 will be carried out using univariate and multivariate logistic regressions. Multivariate logistic regression will consider up to 15 factors.The ambition of this trial, which takes into account the different approaches of geriatric vulnerability, is to define the respective abilities of different operational criteria of frailty to predict patients' outcomes.

ETHICS AND DISSEMINATION

The study protocol was ethically approved. The results of the primary and secondary objectives will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT04422340.

The atypical lymphocyte count: a novel predictive factor for severe thrombocytopenia related to dengue

BACKGROUND

Early identification of patients at risk of severe dengue disease (DD) is critical to guide its management. We evaluated whether the atypical lymphocyte count (ALC), generated from the Sysmex automated full blood count analyzer, is predictive of severe thrombocytopenia secondary to Dengue infection.

METHODS

We prospectively collected data on patients admitted with DD between December 2017 and October 2018. ALC data were extracted from the Sysmex XS500i analyzer from day 1 to day 7 of admission. Clinical data were obtained from patients' medical records.

RESULTS

We enrolled 256 patients with DD. A negative correlation between ALC on admission and platelet count on day 5 to day 7 (Spearmen's correlation; day 5:-0.485, day 6:-0.428 and day 7:-0.344) (p=0.001) was observed. Based on receiver operator characteristic curve analysis, we found that an ALC of >0.5x103/L had 90% sensitivity and 70% specificity for severe thrombocytopenia (platelet count <50x109/L) on day 5. The positive and negative predictive values were 74.4 and 91.2%, respectively (power 84.7).

CONCLUSIONS

We propose that ALC on admission may be a novel negative predictive factor for severe thrombocytopenia on day 5 to day 7 of DD. Further studies are required to validate our findings and evaluate whether ALC is predictive of other complications of DD.

Extended Inflammation Parameters (EIP) as Markers of Immune System Cell Activation in Psoriasis

Psoriasis is an inflammatory, autoimmune disease that affects approximately 2% of the population. The inflammation in psoriasis can be systemic, so despite a predominantly cutaneous manifestation, it also affects the internal organs. The diagnosis and monitoring of the disease are based on the clinical picture. To assess the disorders of other organs, additional tests need to be performed. Recently, the examination of blood morphology has been enriched with modern haematological parameters, i.e., Extended Inflammation Parameters (EIP), which include RE-LYMPH (activated lymphocytes), AS-LYMPH (antibody-producing B lymphocytes), and NEUT-RI and NEUT-GI (activated neutrophils). In the study, higher values of new haematological parameters were observed in individuals with psoriasis than in healthy controls. A higher EIP value was noted in the group of individuals with plaque psoriasis than in the group of individuals with psoriatic arthritis. Implementation of these parameters into routine laboratory analysis will likely make it possible to estimate the severity of the inflammation and improve its assessment.

Mature and Immature/Activated Cells Fractionation: Time for a Paradigm Shift in Differential Leucocyte Count Reporting?

Leucocytes, especially neutrophils featuring pro- and anti-cancerous characteristics, are involved in nearly every stage of tumorigenesis. Phenotypic and functional differences among mature and immature neutrophil fractions are well reported, and their correlation with tumor progression and therapy has emerging implications in modern oncology practices. Technological advancements enabled modern hematology analyzers to generate extended information (research parameters) during complete blood cell count (CBC) analysis. We hypothesized that neutrophil and lymphocyte fractions-related extended differential leucocytes count (DLC) parameters hold superior diagnostic utility over routine modalities. The present study was carried out over a four-and-a-half-year period wherein extended neutrophil (immature granulocyte [IG] and mature neutrophil [NEUT#&]), and lymphocyte (activated/high fluorescence lymphocyte count [HFLC] and resting lymphocyte [LYMP#&]) parameters were challenged over routine neutrophil [NEUT#] and lymphocyte [LYMP#] items in a study population of 1067 hematological neoplasm patients. Extending the classical statistical approaches, machine-learning-backed data visualization was used to explore trends in the study parameters. As a whole, extended neutrophil and lymphocyte count outperformed and was diagnostically more relevant than routine neutrophil and lymphocyte parameters by showing the least difference from their respective (gold-standard) manual DLC counts. The mature neutrophil count was compared to IG, and resting lymphocyte count was compared to HFLC by calling the function ‘correlation’ as a ‘clustering function’ for heatmap based visualization. The aforementioned study parameters displayed close clustering (rearrangement) for their respective study items by presenting distinct trends of equally valuable weights (deviated values), advocating fractions-based extended DLC reporting. Importantly, using a Bland and Altman analysis analogously to a manual neutrophil count, the mature neutrophil count [NEUT#&] remained unbiased since a routine neutrophil count [NEUT#] was found to be a negatively biased. The extended DLC-parameter-driven fractions-based reporting has superior diagnostic utility over classical routine approaches; this finding can largely minimize labor-intensive manual DLC practices, especially in hematology–oncology departments.

Combined hematologic parameters to optimize review criteria on XE-5000

INTRODUCTION

Forty-one consensus review rules are presented to a large number of hematology laboratories worldwide, as suggested by the International Consensus Group for Hematology Review. Research on the review criteria has mainly focused on adjusting the threshold of each parameter to establish optimized criteria with better efficiency based on the consensus group criteria. This study aimed to optimize the review criteria by combining hematologic parameters on a Sysmex XE-5000 hematology analyzer (XE-5000).

MATERIAL AND METHODS

A total of 662 nucleated red blood cell (NRBC) and 406 atypical lymphocyte cell (AL) flagged samples were used to establish hematologic parameters associated with NRBC and AL, respectively. Another set of 1423 optimization samples were used to validate the optimized criteria of NRBC and AL by combining associative hematologic parameters. The efficiency of each set of criteria was compared and optimized to obtain better efficiency, an acceptable slide review rate, and a low false-negative rate.

RESULTS

In the optimization NRBC set combining triple parameters, compared with the default setting (P < .001), the slide review rate declined from 30.26% to 14.42%, and the efficiency increased from 75.65% to 91.02%. In the optimization AL set combining triple parameters, compared with the default setting (P < .001), the slide review rate declined from 40.60% to 11.80%, and the efficiency increased from 64.02% to 93.00%.

CONCLUSIONS

Based on the adjustment of Q-flag values combining associative hematologic parameters, the optimal criteria with a low false-negative rate not only might have a higher efficiency but also may significantly reduce the slide review rate.

M2G1G2 white blood cell flag by three-part automated hematology analyzer: A hint to dengue infection in appropriate clinical context

BACKGROUND

Automated hematology analyzers often generate many flags which can provide important clues to the underlying hematological abnormality. Although pathologists are generally well versed in recognizing the importance of flags indicating potential leukemic blasts, their utility in hinting toward infectious etiology, especially during epidemics, is less well known. We analyzed any abnormal flags generated by a three-part automated hematology analyzer in serologically confirmed cases of dengue.

MATERIALS AND METHODS

The study included 28 patients diagnosed with serologically confirmed dengue infection. The venous samples were run on ABX Miros-60 three-part hematology analyzer. The complete blood count data and any abnormal flags were noted and correlated with peripheral blood film findings in all patients.

RESULTS

An abnormal white blood cell (WBC) flag was noted in all 28 patients, including two in whom all other hematological parameters were within normal limits. In 26 (93%) patients, M2G1G2 WBC flag was noted while the samples of the remaining two patients generated M2G1 and L1M2G1G2 WBC flags, respectively.

CONCLUSION

An abnormal WBC flag, when correlated in appropriate clinical context, especially during a dengue outbreak, can aid in targeting the cohort of patients who will require immediate referral for serological confirmation.

Atypical lymphocyte count correlates with the severity of dengue infection

INTRODUCTION

The early identification of patients at risk of severe dengue infection (DI) is critical to guide clinical management. There is currently no validated laboratory test which can predict severe complications of DI. The Atypical lymphocyte count (ALC) is a research parameter generated at no extra cost when an automated Full Blood Count (FBC) is performed. The purpose of this study was to assess the association of ALC with the severity of DI.

METHODS

We prospectively collected data on patients admitted to Nawaloka Hospital Sri Lanka (NH) with DI between December 2016 and November 2017. DI was diagnosed based on a positive Non-structural antigen 1 (NS1) or dengue IgM antibody. ALC (absolute ALC and percentage) data were extracted from the Sysmex XS500i automated full blood count (FBC) analyzer (Sysmex Corporation Kobe, Japan). Clinical data was recorded from medical records and the computerized data base maintained by NH.

RESULTS

530 patients were enrolled. Patients with clinical manifestations of severe dengue have a significantly higher AL % compared to dengue without warning signs. Patients who presented with respiratory compromise had statistically significantly higher AL% compared to those without. (AL%; 8.65±12.09 vs 2.17±4.25 [p = 0.01]). Similarly, patients who developed hypotension had higher AL% compared to those who did not suffered from shock (AL%; 8.40±1.26 vs 2.18±4.25 [p = 0.001]). The AL% of dengue patients presenting with bleeding, at 4.07%, is also higher than those without bleeding complications, at 2.15%. There was a significant negative association between platelet count and AL% (p = 0.04).

CONCLUSIONS

Clinical manifestations of severe dengue have a significantly higher AL % compared to dengue without warning signs. AL % at presentation may be predictive of severe DI and future larger prospective longitudinal studies should be done to determine if AL % on admission is predictive of the complications of DI.

A novel diagnostic algorithm equipped on an automated hematology analyzer to differentiate between common causes of febrile illness in Southeast Asia

BACKGROUND

Distinguishing arboviral infections from bacterial causes of febrile illness is of great importance for clinical management. The Infection Manager System (IMS) is a novel diagnostic algorithm equipped on a Sysmex hematology analyzer that evaluates the host response using novel techniques that quantify cellular activation and cell membrane composition. The aim of this study was to train and validate the IMS to differentiate between arboviral and common bacterial infections in Southeast Asia and compare its performance against C-reactive protein (CRP) and procalcitonin (PCT).

METHODOLOGY/PRINCIPAL FINDINGS

600 adult Indonesian patients with acute febrile illness were enrolled in a prospective cohort study and analyzed using a structured diagnostic protocol. The IMS was first trained on the first 200 patients and subsequently validated using the complete cohort. A definite infectious etiology could be determined in 190 of 463 evaluable patients (41%), including 89 arboviral infections (81 dengue and 8 chikungunya), 94 bacterial infections (26 murine typhus, 16 salmonellosis, 6 leptospirosis and 46 cosmopolitan bacterial infections), 3 concomitant arboviral-bacterial infections, and 4 malaria infections. The IMS detected inflammation in all but two participants. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the IMS for arboviral infections were 69.7%, 97.9%, 96.9%, and 77.3%, respectively, and for bacterial infections 77.7%, 93.3%, 92.4%, and 79.8%. Inflammation remained unclassified in 19.1% and 22.5% of patients with a proven bacterial or arboviral infection. When cases of unclassified inflammation were grouped in the bacterial etiology group, the NPV for bacterial infection was 95.5%. IMS performed comparable to CRP and outperformed PCT in this cohort.

CONCLUSIONS/SIGNIFICANCE

The IMS is an automated, easy to use, novel diagnostic tool that allows rapid differentiation between common causes of febrile illness in Southeast Asia.

Useful clinical features and hematological parameters for the diagnosis of dengue infection in patients with acute febrile illness: a retrospective study

BACKGROUND

Dengue infection patients are presented with acute febrile illness. Clinical presentations may mimic other infections. The serology for definite diagnosis is costly and inaccessible in many hospitals. We sought to identify the clinical features and hematologic parameters from a complete blood count (CBC) which distinguish dengue infection from other causes.

METHODS

This was a retrospective single center study from Chiang Mai University Hospital. All patients who presented with acute fever between September 2013 and July 2015 were included. The diagnosis of dengue infection must be confirmed by serology. The control groups were patients who presented with acute febrile illness without localizing signs. Clinical data and CBC results were reviewed and compared. The Chi-square test was used to compare categorical variables. The CBC parameters were analyzed using the linear mixed model.

RESULTS

One hundred and fifty-four dengue and 146 control patients were included. Headache, nausea, loss of appetite and bleeding diathesis were significantly symptoms in dengue patients (p < 0.05). There was some diversity in the the CBC in the dengue patients compared to the control group. Moreover, this study also identified the day of fever which these parameters were statistically significant. The dengue group had higher hemoglobin and hematocrit from day 3 to day 10 (p < 0.001), lower white blood cell count from day 1 to day 10 (p < 0.001), lower platelet count from day 3 to day 10 (p < 0.001), higher monocyte on day 1-4 (p < 0.001), higher atypical lymphocyte percentage on day 5-9 (p < 0.001) and higher eosinophil percentage on day 9-10 (p = 0.001). Furthermore, the neutrophil to lymphocyte percentage ratio of dengue group was > 1 on the first 5 days then reversed on day 6 to Day 9 but in non-dengue group, the ratio was always > 1.

CONCLUSION

We identified important clinical features and CBC parameters to differentiate dengue patients from other patients who had acute febrile illness from other causes. This identification could be done in local hospitals to give an accurate diagnosis, enabling further investigation to be tailored and treatment commenced earlier.