Neutrophil VCS Parameters Are Superior Indicators for Acute Infection

Research use only and cell population data items obtained from the Beckman Coulter DxH800 automated hematology analyzer are useful in discriminating MDS patients from those with cytopenia without MDS

We investigated the performance of research use only/cell population data (RUO/CPD) items obtained from the Beckman Coulter DxH800 automated hematologic analyzer in discriminating MDS patients from cytopenic patients without MDS.Total of 14 routine CBC, 18 research use only (RUO) items, and 70 CPD items were obtained retrospectively at diagnosis. The results were then compared between 94 MDS patients and 100 cytopenic patients without MDS. In items with statistically significant differences, receiver operating characteristic (ROC) analysis was performed and the results were compared.Four CBC/RUO items [red cell distribution width-standard deviation (RDW-SD), immature reticulocyte fraction (IRF), mean sphered cell volume (MSCV), high light scatter reticulocytes (HLR)], and two CPD items [mean volume of neutrophils (NE-V-Mean) and mean volume of early granulated cells (EGC-V-Mean)] showed area-under the curve (AUC) scores > 0.750. Notably, four RUO/CPD items (MSCV > 81.4/HLR > 0.15%/NE-V-Mean > 145/EGC-V-Mean > 156) showed high sensitivity (91.9%/93.6%/88.1%/90.2%, respectively) in discriminating MDS patients from cytopenic patients without MDS. With these six items, scores ≥ 4 (defined as ≥ 4 items exceeding cutoff values out of six items) showed AUC scores/sensitivity/specificity/accuracy (0.891/87.3%/79.0%/83.0%, respectively).Six CBC/RUO/CPD items showed satisfactory AUC scores of > 0.750, and four RUO/CPD items showed high sensitivity in discriminating MDS patients from cytopenic patients without MDS. Scoring system with six items showed high sensitivity, specificity, and accuracy with decision criteria of ≥ 4 scores. Therefore, DxH800 RUO/CPD items would be useful in discriminating MDS patients from cytopenic patients without MDS.

Utility of VCS Parameters as a Cost-effective and Early Marker of Sepsis: A Hospital-based Study

Introduction

Sepsis is a life-threatening condition. Nowadays, hospitals rely on laboratory parameters like CRP and procalcitonin to detect sepsis. There is a need to evaluate and validate more accurate and early predictors of sepsis in critically ill patients. We analyzed volume, conductivity, and scatter (VCS) parameters of leukocytes in sepsis patients and compared them with the control group with no illness.

Materials and methods

It was a prospective case-control study. A total of 80 patients were studied with 40 sepsis cases and 40 controls. Peripheral smear examination was done in all the cases. Other parameters, such as WBC count, neutrophil%, absolute neutrophil count (ANC), High-sensitive C-reactive protein (hs-CRP), procalcitonin, and blood cultures were analyzed. We took the data of the patients from medical records and correlated it with other tests. Complete blood picture reports were generated by the Beckman Coulter LH series (LH 750 and 780). VCS parameters for neutrophils, lymphocytes and monocytes were compared between both groups. The results were analyzed using SPSS software (16.0 version).

Results

The age group was 20-85 years with male predominance. The mean neutrophil volume (MNV) and mean monocyte volume (MMV) were higher in the sepsis group when compared with the control group. The mean neutrophil conductivity and scatter was lower in the sepsis group and comparatively higher in the control group, but it was insignificant. The mean neutrophil volume values were higher in the sepsis group even with low total leukocyte count (TLC) when the patient had sepsis. There is no change in the mean lymphocyte VCS parameter and mean monocyte conductivity, scatter in both the groups.

Conclusion

The mean neutrophil volume and MMV are found to be good sensitive markers in the prediction of sepsis. Even when TLC is on the lower side in patients with sepsis, these parameters predict sepsis accurately. This helps clinicians to assess sepsis in patients at an early stage and has an important practical implication.

How to cite this article

Goyal H, Singhal A, Joseph M. Utility of VCS Parameters as a Cost-effective and Early Marker of Sepsis: A Hospital-based Study. Indian J Crit Care Med 2023;27(9):647-650.

Role of Automated Volume, Conductivity and Scatter (VCS) Parameters of Neutrophils as Indicators of Sepsis

This study was done to evaluate the role of automated volume, conductivity and scatter (VCS) parameters of neutrophils as indicators of sepsis and its differentiation from other inflammatory disorders. In this cross-sectional study, 225 patients with culture proven or with clinical evidence of sepsis were included along with an equal number of healthy controls. In addition, 138 patients with non-infective inflammatory conditions-acute pancreatitis (50), burns (45) and acute myocardial infarction (43) were also included. Complete blood count was done on LH750 automated hematology analyser (Beckman Coulter). VCS data; mean neutrophil volume (MNV), mean neutrophil conductivity (MNC) and mean neutrophil scatter (MNS) for all patients was recorded. MNV was high (p < .0001) while MNS was lower (p < .0001) in patients with sepsis compared to the control group. MNC was comparable between the two groups (p = .4735). On subgroup analysis of patients with sepsis, significant difference in MNV (p = .0009) and MNS (p = .0210) was observed in patients with leukopenia, normal TLC and leucocytosis. Youden Index was maximum (71%) at MNV of 144.6 (sensitivity-82.7%; specificity-88.5%) and MNV of 147.9 (sensitivity-75.6%; specificity-95.6%) for sepsis. On comparing patients with sepsis with acute pancreatitis and myocardial infarction, MNV and MNC were significantly higher in patients with sepsis. MNV is a useful, inexpensive parameter which can be accessed during a routine CBC run from the raw data. It can be utilized as an early indicator of sepsis as an adjunct to the clinical diagnosis in suspect patients. However, its availability in only select hematology analyzers may limit its use.

Effects of Smoking on Volume, Conductivity and Scatter Parameters of Leukocytes

Aim: In this study, we aimed to determine changes in leukocytes volume, conductivity and scatter parameters in smokers compared to non-smokers. Methods: A total of 117 individuals (45 smokers and 72 non-smokers) were included in the study. While those who smoked at least 10 pack-years were included in the case group, those who never smoked at all were included in the control group. Results: While there was a statistically significant difference in mean neutrophil volume, mean neutrophil conductivity, mean lymphocyte conductivity, mean lymphocyte scatter, mean monocyte volume, mean monocyte conductivity, mean monocyte scatter, mean eosinophil conductivity values between the two groups, there was no statistically significant difference in mean neutrophil scatter, mean lymphocyte volume, mean eosinophil volume, mean eosinophil scatter values between the two groups. Conclusion: This study showed that smoking affected volume, conductivity and scatter parameters. Clinicians should consider whether the patient smokes if they want to diagnose any diseases using volume, conductivity and scatter parameters. Keywords: smoking, leukocytes, conductivity, scattering, neutrophils

The morphological changes of monocytes in peripheral blood as a potential indicator for predicting active pulmonary tuberculosis

BACKGROUND

Monocytes play a crucial role in immune response against Mycobacterium tuberculosis infection. The purpose of this current study was to investigate the morphology present on monocytes in peripheral blood from patients with active pulmonary tuberculosis (APTB) and the laboratory performance of the changes for discriminating cases from normal healthy subjects (NHS).

METHOD

A total of 71 peripheral blood samples from patients with APTB, and 65 samples from NHS were analyzed. The mean monocyte volume with its distribution width and mean monocyte conductivity as well as monocyte light scatter were detected by VCS technology used on the LH750 hematology analyzer. Correlations of these changes with the serum cytokine level in the immune alterations were further evaluated. The Receiver operating characteristic curve (ROC) analysis was used to highlight the clinical implication.

RESULTS

In APTB patients, the mean monocyte volume showed significant difference associated with an evident elevation in the mean monocyte volume distribution width compared to those in NHS. Furthermore, the mean monocyte volume had positive relationship with the serum level of interleukine-1β response to M. tuberculosis infection. Simultaneous measurement of the mean monocyte volume and its distribution width was able to distinguish active infection with an excellent sensitivity of 84.5% and specificity of 90.5% comparable to those obtained from pro-inflammatory cytokine interleukine-6 identifying APTB with great accuracy.

CONCLUSION

The morphological changes of monocytes particular increased mean volume may be a potential indicator to predict active tuberculosis infection.

Discriminating myelodysplastic syndrome and other myeloid malignancies from non-clonal disorders by multiparametric analysis of automated cell data

BACKGROUND

We investigated the usefulness of novel complete blood count (CBC) data for discriminating myeloid malignancies from non-clonal CBC abnormalities.

METHODS

Data were obtained during routine CBC tests of 119 samples from 37 myelodysplastic syndrome (MDS) patients, 92 samples from 45 myeloproliferative neoplasm (MPN) patients, and 15 samples from 11 chronic myelogenous leukemia (CML) patients using a DxH800 (Beckman Coulter). Data obtained from patients with hypocellular bone marrow and from those with other non-clonal diseases with CBC abnormalities were included in the comparisons.

RESULTS

For cell population data of neutrophils, the means of median, upper median, lower median, and low angle light scatters were significantly lower in MDS patients than in patients without hematological malignancies. Low hemoglobin density (LHD) did not significantly differ between the MDS and non-clonal cytopenia patients, but it was significantly higher in the MPN and CML patients. We selected 13 parameters and scored the MDS diagnosis using cut-off values obtained from receiver operating characteristic (ROC) curve analysis. Using a score > 9, MDS was distinguished from non-clonal cytopenia with a sensitivity of 92.4% and a specificity of 85.4%.

CONCLUSIONS

Multiparametric analyses of new automated parameters are useful for discriminating MDS from non-clonal cytopenia.

The Importance of Mean Neutrophil Volume (MNV) Values in Differential Diagnosis of Bacterial Sepsis

INTRODUCTION

Bloodstream infections are a significant cause of morbidity and mortality in hospitalized patients. Blood cultures and other laboratory tests are used for diagnosis. Among these tests, the mean neutrophil volume (MNV) value is reported as a potential indicator that supports the diagnosis of sepsis. Our study identified the MNV values of patients via microorganisms cultivated from blood cultures and examined the role of these MNV values in the early diagnosis of bloodstream infections.

METHODS

Our study surveyed retrospectively 148 adult patient blood culture samples that had been sent to our laboratory. BACTEC 9050 (Becton Dickinson, USA) and BACTEC FX 40 (Becton Dickinson, USA) devices were used in the blood culture isolation procedures.

RESULTS

The average MNV value was found to be 159.0 (+11.3) in patients whose sepsis originated from Gram-negative bacteria, and the average MNV value was measured as 152.4 (+14.5) among patients whose sepsis originated from Gram-positive bacteria. When comparing groups of patients having Gram-negative bacteria and patients having Gram-positive bacteria, a statistically significant difference (p = 0.041) in the MNV values was observed.

CONCLUSION

The MNV value was found to be statistically significant in discrimination of Gram-negative and Gram-positive sepsis. Considering these findings, measuring the MNV values can help initiate proper antibiotic treatment more quickly, and we think that this will help lower the mortality rate. However, these findings should be supported with further studies.

The VCS parameters: Potential hematological indicators for predicting antituberculosis drug-induced neutropenia

BACKGROUND

The morphological changes in activated neutrophils associated with antituberculosis drugs can be measured by volume, conductivity, and scatter (VCS) technology on the Coulter LH750 hematology analyzer. We conducted the current study to further validate the clinical usefulness of the neutrophil VCS parameters in predicting drug-induced neutropenia.

METHODS

Peripheral blood samples were collected from 52 patients with drug-induced neutropenia, 309 patients without any abnormal CBC, and 237 healthy controls. The mean neutrophil volume (MNV) with its distribution width (NDW) and the mean neutrophil scatter (MNS) were studied.

RESULTS

We observed a significant increase in the MNV and NDW as well as a significant decrease in the MNS in neutropenia patients approximately one week prior to development of neutropenia compared to healthy controls as well as to case controls. In addition, the delta MNV and delta MNS were respectively correlated well with delta absolute neutrophil counts when neutropenia occurred. The ROC curve analyses showed that the MNV、NDW and MNS had larger areas under curves compared to conventional parameters. With a cutoff of 150.15 for the MNV, a sensitivity of 84.4% and specificity of 75.7% were achieved prior to neutropenia.

CONCLUSION

The neutrophil VCS parameters may be clinically useful as potential hematological indicators for predicting antituberculosis drug-induced neutropenia.

The value of eosinophil VCS parameters in predicting hepatotoxicity of antituberculosis drugs

INTRODUCTION

Drug-induced liver injury (DILI) is the most frequent cause of discontinuation of antituberculosis medication and difficult to predict. In recent years, liver eosinophilia has been associated with incidence of DILI. We hypothesize that morphologic changes in reactive eosinophils associated with DILI may be determined by LH750 (Beckman Coulter, Fullerton, CA) with VCS technology.

METHODS

The absolute eosinophil (AEC), percentage of eosinophil (EOSI%), VCS parameters, and standard deviation (SD) of 500 health controls, 376 patients without DILI, and 50 DILI patients were compared in terms of diagnostic sensitivity and specificity for DILI.

RESULTS

In DILI patients, the increased mean eosinophil volume (MEV) and size variability (MEV-SD) were observed prior to alanine aminotransferase (ALT) elevations. The MEV was correlated well with ALT after therapy. The ROC curve analyses revealed that the MEV and MEV-SD had larger areas under curves (0.894, 0.815, in the week prior to DILI) compared to other parameters. Using a cutoff of 163.15 fL for the MEV and a cutoff of 17.11 for MEV-SD, the sensitivities of 81% and 72% and specificities of 82% and 80% were achieved, respectively, which are higher than other parameters prior to DILI occurred.

CONCLUSIONS

The MEV with size variability (MEV-SD) is a quantitative, objective, and more sensitive parameter and has a potential to be an additional indicator for DILI.

Volume Conductivity and Scatter Parameters as an Indicator of Acute Bacterial Infections by the Automated Haematology Analyser

INTRODUCTION

Complete blood picture is the first and foremost investigation ordered for evaluation of acute infectious processes which require early and prompt intervention. With the advent of automated Coulter (®) Haematology analysers, the Volume, Conductivity & Scatter parameters of the leucocytes could be analysed for the early detection of the infections.

AIM

To evaluate the clinical usefulness of Volume, Conductivity & Scatter parameters of neutrophils & monocytes in predicting the onset of acute bacterial infections.

MATERIALS AND METHODS

Peripheral blood samples from 94 patients with infections (systemic infections n=36 & localised infections n=58) and 46 control subjects were studied using the Volume, Conductivity & Scatter parameters by the Coulter Haematology analyser.

RESULTS

We observed a significant increase in the mean channel of neutrophil volume & mean channel of monocyte volume from patients with infections (both systemic & localised) as compared with control subjects (Mean Neutrophil Volume: 158.3 ± 13.7 vs 137.2 ± 4.3; p<0.001) & (Mean Monocyte Volume: 177.8± 16 vs 161.7 ± 6.04; p <0.001). However, there was no significant difference in the Mean Neutrophil Volume of patients with systemic infection & localised infections (160.5±17.5 vs 156.8±10.5, p>0.05).

CONCLUSION

The Volume, Conductivity & Scatter parameters like Mean Neutrophil Volume & Mean Monocyte Volume are more sensitive parameters and could prove to be a quick diagnostic indicator of acute bacterial infections.

VCS parameters of neutrophils, monocytes and lymphocytes may indicate local bacterial infection in cancer patients who accepted cytotoxic chemotherapeutics

Bacterial infections increased greatly in cancer patients who accepted cytotoxic chemotherapeutics. VCS parameters of neutrophils were reported to be an indicator for acute bacterial infection accompanied by increased WBC counts. Here we explored the possibility of VCS parameters of neutrophils, monocytes and lymphocytes in indicating the local bacterial infection in cancer patients. A total of 310 cancer patients and 90 healthy controls were retrospectively analyzed, and 190 of them were diagnosed as acute local bacterial infection. The VCS parameters acquired from a Beckman Coulter LH750 haematology analyzer were investigated to determine which VCS parameters could indicate local bacterial infection in cancer patients with leucopenia caused by cytotoxic agents. VCS parameters of cancer patients were significantly affected by infection. For diagnosing bacterial infection of cancer patients, the best single indicator was mean monocyte light scatter (MMS) with a sensitivity of 95.12 % and a specificity of 58.82 % and the area under the curve (AUC) was 0.792. A combination of the following five parameters: mean neutrophil volume (MNV), MMS, mean lymphocyte conductivity (MLC), mean lymphocyte light scatter (MLS) and neutrophil volume distribution width (NDW) could provide a better index in diagnosing bacterial infection than any single parameter (sensitivity 75.8 %, specificity 64.72 %, AUC 0.763). Taking WBC counts into consideration, VCS parameters could better indicate bacterial infection for cancer patients with abnormal WBC level than that with normal WBC level. Aside from neutrophils, the VCS of monocytes and lymphocytes were also ideal indicators for bacterial infection. The combination of VCS parameters could increase the sensitivity, specificity and accuracy of diagnosis of cancer patients.

Elevated mean neutrophil volume represents altered neutrophil composition and reflects damage after myocardial infarction

Myocardial infarction (MI) induces an inflammatory response in which neutrophils fulfill a prominent role. Mean neutrophil volume (MNV) represents the average size of the circulating neutrophil population. Our goal was to determine the effect of MI on MNV and investigate the mechanisms behind MNV elevation. MNV of 84 MI patients was compared with the MNV of 209 stable angina patients and correlated to simultaneously measured CK levels. Fourteen pigs were subjected to temporary coronary balloon occlusion and blood was sampled at multiple time points to measure MNV. Echocardiography was performed followed by ex vivo infarct size assessment after 72 h. MNV was higher in MI patients compared to stable angina patients (602 SD26 AU vs. 580 SD20 AU, p < 0.0001) and correlated with simultaneously measured CK levels (R = 0.357, p < 0.0001). In pigs, MNV was elevated post-MI (451 SD11 AU vs. 469 SD12 AU), p < 0.0001). MNV correlated with infarct size (R = 0.705, p = 0.007) and inversely correlated with left ventricular ejection fraction (R = −0.718, p = 0.009). Cell sorting revealed an increased presence of banded neutrophils after MI, which have a higher MNV compared to mature neutrophils post-MI (495 SD14 AU vs. 478 SD11 AU, p = 0.012). MNV from coronary sinus blood was higher than MNV of neutrophils from simultaneously sampled arterial blood (463 SD7.6 AU vs. 461 SD8.6 AU, p = 0.013) post-MI. The current study shows MNV is elevated and reflects cardiac damage post-MI. MNV increases due to altered neutrophil composition and systemic neutrophil activation. MNV may be an interesting parameter for prognostic assessment in MI and provide new insights into pathological innate immune responses evoked by ischemia–reperfusion.

Automated screening for myelodysplastic syndromes through analysis of complete blood count and cell population data parameters

The diagnosis of myelodysplastic syndromes (MDS) requires a high clinical index of suspicion to prompt bone marrow studies as well as subjective assessment of dysplastic morphology. We sought to determine if data collected by automated hematology analyzers during complete blood count (CBC) analysis might help to identify MDS in a routine clinical setting. We collected CBC parameters (including those for research use only and cell population data) and demographic information in a large (>5,000), unselected sequential cohort of outpatients. The cohort was divided into independent training and test groups to develop and validate a random forest classifier that identifies MDS. The classifier effectively identified MDS and had a receiver operating characteristic area under the curve (AUC) of 0.942. Platelet distribution width and the standard deviation of red blood cell distribution width were the most discriminating variables within the classifier. Additionally, a similar classifier was validated with an additional, independent set of >200 patients from a second institution with an AUC of 0.93. This retrospective study demonstrates the feasibility of identifying MDS in an unselected outpatient population using data routinely collected during CBC analysis with a classifier that has been validated using two independent data sets from different institutions.

Delta mean neutrophil volume (ΔMNV) is comparable to procalcitonin for predicting postsurgical bacterial infection

BACKGROUND

The Coulter LH750 (Beckman Coulter, Brea, CA) analyzer can determine intrinsic biophysical properties of white blood cell (WBC), known as cell population data. Previous studies have shown that mean neutrophil volume (MNV) was significantly increased in postsurgical patients with bacterial infection. To further validate its potential clinical usefulness, we investigate the changes in MNV before and after surgery, called ΔMNV. We also compare the ΔMNV with procalcitonin (PCT) and C-reactive protein (CRP) in terms of diagnostic sensitivity and specificity for postsurgical bacterial infection.

METHODS

Blood samples from 300 healthy controls, 219 cardiac surgical patients without postsurgical infection, and 31 cardiac surgical patients complicated with postsurgical bacterial infection were studied.

RESULTS

There are no statistically significant differences for WBC count and neutrophil percentage prior to or after surgery between postsurgical noninfected and infected patients. However, the ΔMNV is significantly increased in postsurgical infected patients when compared with noninfected patients (P < 0.05). The receiver-operating characteristics analysis reveals the ΔMNV and PCT have largest areas under curves (0.92, 0.93 on the second day and 0.94, 0.99 on the third day postsurgery, respectively) compared to other parameters.

CONCLUSION

ΔMNV shows comparable sensitivity and specificity to PCT and superior sensitivity and specificity to WBC or CRP for predicting postsurgical bacterial infection. The potential clinical application of this parameter merits further exploration in a larger prospective study.

Automated screening for tuberculosis by multiparametric analysis of data obtained during routine complete blood count

INTRODUCTION

The main goal of this study was to develop a multiparametric cell population data (CPD) model that combines information from several morphologic parameters generated by DxH800, in addition to the traditional parameters regularly reported in the CBC-diff, and to test the performance of this model in screening the general population for primary tuberculosis (TB).

METHODS

A total of 3741 study cases were divided into two groups, test and validation set at cut-off value of 6000 WBCs/μL. We developed multiparametric model for primary TB screening (TB hemeprint), selected CPD, and calculated parameters which could discriminate primary TB from other non-TB diseases and normal control in test set. We applied it to the validation set, which was a set of completely different samples, to test its reproducibility if applied to a routine laboratory test.

RESULTS

After screening primary TB using TB hemeprint, sensitivity, specificity, PPV, and NPV were 85.4%, 89.6%, 31.1%, and 99.1%, respectively, in primary TB with lower than 6000 WBCs/μL of test set (test set-L). In primary TB with higher than 6000 WBCs/μL of test set (test set-H), those values were 83.1%, 85.6%, 29.7%, and 98.6%, respectively. There were only 0.4% (2/461) and 0.6% (2/326) of normal control samples included in test set-L and -H, respectively. Diagnostic efficiencies except sensitivity in each validation set were very comparable with those in each test set.

CONCLUSION

Tuberculosis hemeprint may allow us to screen primary TB with acceptable sensitivity and specificity using combination of TB-specific CPD and calculated parameters.

Biological variations of leukocyte numerical and morphologic parameters determined by UniCel DxH 800 hematology analyzer

CONTEXT

The Coulter DxH 800 hematology analyzer can determine leukocyte numerical parameters (total leukocyte counts and differentials). It also measures intrinsic biophysical properties of these cells in their near-native state. These morphologic measurements are known as cell population data (CPD).

OBJECTIVE

To study, for the first time, the biological variations of morphologic parameters or CPD and reinvestigate numerical parameters using the newest Coulter hematology analyzer. Design.-Forty adult volunteers (21 women, 19 men) were included. All participants maintained their normal lifestyles. Blood samples were drawn in duplicate by a single experienced phlebotomist and analyzed within 2 hours using a single analyzer. Before each batch analysis, the instrument quality controls were performed using the same lots of reagents.

RESULTS

Within-subject (CV(I)) and between-subjects (CV(G)) biological variations for numerical parameters are smaller than previously reported. Cell population data have much smaller overall CV(I) and CV(G) compared to numerical parameters, suggesting that these parameters are less variable around the homeostatic set point intraindividually and interindividually. Index of individuality (ratio of CV(I)/CV(G)) for CPD was low. In addition, intraday and interday biological variations of all parameters are fairly constant.

CONCLUSIONS

These observations are clinically valuable. Data on CV(I) and analytical precision may be used to generate objective delta-check values for use in quality management. Comparing CV(I) and CV(G) on CPD may allow us to decide the utility of traditional population-based reference ranges. Documentation of CPD on biological variations is an essential prerequisite in the development of any new application clinically.

The lymph index: a potential hematological parameter for viral infection

OBJECTIVE

An LH750 hematology analyzer with VCS (volume, conductivity, and light scatter) technology can determine morphologic properties of peripheral leukocytes, known as cell population data (CPD). We have previously demonstrated that the lymphocyte CPD exhibit significant changes in acute hepatitis B virus infection. A simplified lymphocyte CPD, the lymph index, was proposed. We conducted the current study to further evaluate the clinical usefulness of the lymph index, and included patients with various viral infections, as well as those with acute bacterial infections.

METHODS

Peripheral blood was collected from 72 patients with viral infections, 46 patients with acute bacterial infections, and 204 controls. The lymphocyte CPD included the mean volume (LV) with its standard deviation (LV-SD) and the conductivity (LC). The lymph index was calculated as LV × LV-SD ÷ LC.

RESULTS

The lymph index was significantly increased in viral infections and only mildly increased in acute bacterial infections compared to controls. Using a lymph index cutoff value of ≥ 12.92, we achieved 91.67% sensitivity and 97.2% specificity for diagnosing viral infection.

CONCLUSIONS

The findings may be clinically useful since these morphological parameters are readily obtained by hematology analyzer during automated leukocyte differentials. They are quantitative, objective, and fast. The lymph index could be a potential hematological parameter for viral infection.