Pseudo-NRBC in the Mindray BC-6800Plus analyzer: A clue for diagnostic anticipation of fungemia. Experimental and preliminary clinical reports

INTRODUCTION

Candidemia can be a significant cause of death in immunosuppressed or debilitated patients particularly. Abnormalities of the instrumental cytograms of some hematological analyzers, such as Mindray BC-6800Plus, can be related to circulating Candida. We studied the possible diagnostic usefulness of this information.

METHODS

A fungal bloodstream infection has been simulated by adding aliquots of Candida albicans, Candida parapsilosis, and Candida glabrata to 75 leftovers and anonymized peripheral blood samples. Cytographic abnormalities like those of experimental samples were used to select patients with possible fungemia. The microscopic review of peripheral blood smears constituted the confirmatory method.

RESULTS

In all experimental samples, the various Candida types caused pseudo-NRBC and morphological abnormalities of WNB and DIFF cytograms. Circulating blastospores, free or engulfed by neutrophils, were the microscopic findings in the peripheral blood smears. In the clinical verification, 72 patients were recruited based on the presence of an evocative cluster in the WNB and DIFF cytograms. The microscopic review of 39 out of 72 samples was positive for NRBC. According to blood cultures, light microscopy revealed fungal forms of several Candida or non-Candida types in the remaining 33 samples. Nine of these cases were not yet known to suffer from bloodstream infection.

CONCLUSIONS

Although further confirmatory clinical studies are required for these diagnostic abilities, the BC 6800Plus cytographic abnormalities related to fungemia have proven helpful in rapidly monitoring persistent fungemia in already diagnosed patients. In unknown or undiagnosed cases, they could be the trigger point for the subsequent diagnostic-therapeutic pathway.

Nucleated red blood cells are a late biomarker in predicting intensive care unit mortality in patients with COVID-19 acute respiratory distress syndrome: an observational cohort study

Background

Nucleated red blood cells (nRBC) are precursor cells of the erythropoiesis that are absent from the peripheral blood under physiological conditions. Their presence is associated with adverse outcomes in critically ill patients. This study aimed to evaluate the predictive value of nRBC on mortality in intensive care unit (ICU) patients with COVID-19 acute respiratory distress syndrome (ARDS).

Material and methods

This retrospective, observational cohort study analyzed data on 206 ICU patients diagnosed with COVID-19 ARDS between March 2020 and March 2022. The primary endpoint was ICU mortality, and secondary endpoints included ICU and hospital stay lengths, ventilation hours, and the time courses of disease severity scores and clinical and laboratory parameters.

Results

Among the included patients, 68.9% tested positive for nRBC at least once during their ICU stay. A maximum nRBC of 105 µl-1 had the highest accuracy in predicting ICU mortality (area under the curve of the receiver operating characteristic [AUCROC] 0.780, p < 0.001, sensitivity 69.0%, specificity 75.5%). Mortality was significantly higher among patients with nRBC >105 µl-1 than ≤105 µl-1 (86.5% vs. 51.3%, p = 0.008). Compared to patients negative for nRBC in their peripheral blood, those positive for nRBC required longer mechanical ventilation (127 [44 - 289] h vs. 517 [255 - 950] h, p < 0.001), ICU stays (12 [8 - 19] vs. 27 [13 - 51] d, p < 0.001), and hospital stays (19 [12 - 29] d vs. 31 [16 - 58] d, p < 0.001). Peak Sepsis-related Organ Failure Assessment (SOFA), Simplified Acute Physiology Score, PaO2/FiO2, interleukin-6, and procalcitonin values were reached before the peak nRBC level. However, the predictive performance of the SOFA (AUCROC 0.842, p < 0.001) was considerably improved when a maximum SOFA score >8 and nRBC >105 µl-1 were combined.

Discussion

nRBC predict ICU mortality and indicate disease severity among patients with COVID-19 ARDS, and they should be considered a clinical alarm signal for a worse outcome. nRBC are a late predictor of ICU mortality compared to other established clinical scoring systems and laboratory parameters but improve the prediction accuracy when combined with the SOFA score.

Diagnostic Value and Prognostic Significance of Nucleated Red Blood Cells (NRBCs) in Selected Medical Conditions

Nucleated red blood cells (NRBCs) are premature erythrocyte precursors that reside in the bone marrow of humans of all ages as an element of erythropoiesis. They rarely present in healthy adults' circulatory systems but can be found circulating in fetuses and neonates. An NRBC count is a cost-effective laboratory test that is currently rarely used in everyday clinical practice; it is mostly used in the diagnosis of hematological diseases/disorders relating to erythropoiesis, anemia, or hemolysis. However, according to several studies, it may be used as a biomarker in the diagnosis and clinical outcome prognosis of preterm infants or severely ill adult patients. This would allow for a quick diagnosis of life-threatening conditions and the prediction of a possible change in a patient's condition, especially in relation to patients in the intensive care unit. In this review, we sought to summarize the possible use of NRBCs as a prognostic marker in various disease entities. Research into the evaluation of the NRBCs in the pediatric population most often concerns neonatal hypoxia, the occurrence and consequences of asphyxia, and overall neonatal mortality. Among adults, NRBCs can be used to predict changes in clinical condition and mortality in critically ill patients, including those with sepsis, trauma, ARDS, acute pancreatitis, or severe cardiovascular disease.

The Presence of Circulating Nucleated Red Blood Cells Is Associated With Disease Severity in Patients of Hemorrhagic Fever With Renal Syndrome

Hemorrhagic fever with renal syndrome (HFRS) is a regional infectious disease of epidemic potential caused by the Hantaan virus (HTNV). Red blood cells (RBCs) are the major components of peripheral blood. However, pathological changes in RBCs and the underlying mechanisms during HTNV infection remain largely unclear. Therefore, this study sought to explore changes in RBCs in the peripheral blood of HFRS patients. We isolated PBMCs from HFRS patients and performed single-cell RNA sequencing. The results showed that clusters of RBCs in the peripheral blood of HFRS could be classified as nucleated red blood cells (NRBC) based on their cellular components, gene expression profiles and cell surface markers. In addition, it was shown that the higher the count of NRBC in peripheral blood, the more severe the disease status was. Moreover, hematological indices related to RBCs were analyzed and the results showed that impairment in the folate pathway might be the possible reason behind the presence of NRBCs. This study, for the first time showed that the presence of NRBCs in the peripheral blood of HFRS patients was associated with disease severity. This was also the first study to show that infection with the HTNV virus hindered the maturation of RBCs. Therefore, this work provides further insights on the role of and pathological changes in RBCs during HTNV infection.

Diagnostic Value of Non-Invasive Prenatal Screening of β-thalassemia by Cell Free Fetal DNA and Fetal NRBC

BACKGROUND

Beta thalassemia is a common disorder with autosomal recessive inheritance. The most prenatal diagnostic methods are the invasive techniques that have the risk of miscarriage. Now the non-invasive methods will be gradually alternative for these invasive techniques.

OBJECTIVE

The aim of this study is to evaluate and compare the diagnostic value of two non-invasive diagnostic methods for fetal thalassemia using cell free fetal DNA (cff-DNA) and nucleated RBC (NRBC) in one sampling community.

METHODS

10 ml of blood was taken in two k3EDTA tube from 32 pregnant women (mean of gestational age = 11 weeks), who themselves and their husbands had minor thalassemia. One tube was used to enrich NRBC and other was used for cff-DNA extraction. NRBCs were isolated by MACS method and immunohistochemistry; the genome of stained cells was amplified by multiple displacement amplification (MDA) procedure. These products were used as template in b-globin segments PCR. cff-DNA was extracted by THP method and 300 bp areas were recovered from the agarose gel as fetus DNA. These DNA were used as template in touch down PCR to amplify b-globin gen. The amplified b-globin segments were sequenced and the results compared with CVS resul.

RESULTS

The data showed that sensitivity and specificity of thalassemia diagnosis by NRBC were 100% and 92% respectively and sensitivity and specificity of thalassemia diagnosis by cff-DNA were 100% and 84% respectively.

CONCLUSION

These methods with high sensitivity can be used as screening test but due to their lower specificity than CVS, they cannot be used as diagnostic test.

Emergence role of nucleated red blood cells in molecular response evaluation for chronic myeloid leukemia

Purpose

To investigate and evaluate the role of nucleated red blood cells (NRBCs) and other markers in predicting remission failure in chronic myeloid leukemia (CML) patients treated with imatinib.

Methods

Seventy-one CML patients with BCR-ABL(+) in bone marrow cells were selected for this study. Molecular response evaluations were done every three months according to the recommendations of European LeukemiaNet (ELN). Patients were defined as remission failure if BCR-ABL transcripts >10% after 6 months (T6), >1% after 12 months (T12), and >0.1% after 18 (T18) months of treatment. The logistic regression was used to determine the optimal cut-off point of each marker and test the association of marker level with remission failure.

Results

The median NRBC, white blood cells, blast cells, basophils, and platelets were declined parallel with the decreases of BCR-ABL transcripts in bone marrow cells after 6 months of treatment (P<0.001). In addition, NRBC was almost not found in the blood of patients who archived good response at T6, T12, and T18 time-points. Interestingly, patients with a high level of NRBC (cut-off: 0.003×10⁹/L) have higher BCR-ABL transcripts compared to others. The elevated NRBC at T6 (OR=6.49, P=0.042), T12 (OR=6.73, P=0.007), and T18 (OR=5.96, P=0.009) time-points was identified as an independent factor for the remission failure.

Conclusion

The results of this study showed that a high number of NRBC in peripheral blood of CML patients is associated with higher BCR-ABL transcripts in bone marrow cells. The elevated NRBC might serve as an independent marker for molecular remission failure in CML.

Neutrophil-to-lymphocyte ratio, nucleated red blood cells and erythrocyte abnormalities in canine systemic inflammatory response syndrome

Systemic inflammatory response syndrome (SIRS) is the manifestation of the systemic response to an infectious or non-infectious disease. We evaluated the association between erythrocyte parameters, including nucleated red blood cells (NRBCs) and leukocyte ratios (NLR, neutrophil-to-lymphocyte ratio; BLR, band neutrophil-to-lymphocyte ratio; BLNR, band neutrophil-to-neutrophil-to-lymphocyte ratio). A review of the medical records was conducted searching SIRS dogs among those admitted to our intensive care unit and a SIRS grading was obtained based on how many criteria were fulfilled. The Acute Patient Physiology and Laboratory Evaluation (APPLE_fast) score was assessed in each dog. Survival rate was assessed 15 days after admission. Dogs with clinical and/or clinicopathological signs of hemolytic or hemorrhagic disorders were excluded. Dogs with ≥2 criteria of SIRS along with a documented underlying infectious cause were recorded as septic (32/90, 35%). A SIRS grading >2 (p = .001) and an APPLE_fast score > 25 (p = .03) were associated with mortality. Twenty-two of SIRS dogs (24%) showed circulating NRBCs. The occurrence of circulating NRBCs was associated with the mortality in SIRS groups (p = .0025). The median NLR was 11.69 and NLR was lower in septic dogs compared to non-septic ones (p = .0272). APPLE_fast, SIRS grading and circulating NRBCs may be considered as negative prognostic factors in canine SIRS. NLR could be a useful tool in dogs with SIRS, which was significantly lower in the septic group. Further prospective, large-scale studies investigating BLR and BNLR in canine SIRS are warranted.

Hospital Disaster Preparedness in Switzerland Over a Decade: A National Survey

OBJECTIVE

The present study aimed to provide a comprehensive assessment of Swiss hospital disaster preparedness in 2016 compared with the 2006 data.

METHODS

A questionnaire was addressed in 2016 to all heads responsible for Swiss emergency departments (EDs).

RESULTS

Of the 107 hospitals included, 83 (78%) returned the survey. Overall, 76 (92%) hospitals had a plan in case of a mass casualty incident, and 76 (93%) in case of an accident within the hospital itself. There was a lack in preparedness for specific situations: less than a third of hospitals had a specific plan for nuclear/radiological, biological, chemical, and burns (NRBC+B) patients: nuclear/radiological (14; 18%), biological (25; 31%), chemical (27; 34%), and burns (15; 49%), and 48 (61%) of EDs had a decontamination area. Less than a quarter of hospitals had specific plans for the most vulnerable populations during disasters, such as seniors (12; 15%) and children (19; 24%).

CONCLUSIONS

The rate of hospitals with a disaster plan has increased since 2006, reaching a level of 92%. The Swiss health care system remains vulnerable to specific threats like NRBC. The lack of national legislation and funds aimed at fostering hospitals' preparedness to disasters may be the root cause to explain the vulnerability of Swiss hospitals regarding disaster medicine. (Disaster Med Public Health Preparedness. 2019;13:433-439).

Validity of Selected WBC Differentiation Flags in Sysmex XT-1800i

BACKGROUND

Automatic Cell Counter devises make the CBC differential very easy and delivering the results in few second. However, the problem with this device is facing a flag requires a time-consuming microscopic review of the specimen which causes unacceptable wait times for patient as well as costs for laboratories. In this study, we calculated the validity of WBC diff flags in Sysmex XT-1800i. In addition, we verified the correlation between manual and automated samples.

METHODS

Overall, 1095 flagged samples were selected in the period of 6 weeks (Imam Hospital complex, Tehran Iran, 2014). The results of both automated and manual counting of the samples were carefully studied and compared. Totally, 624 NRBC flags, 450 Blast flags, 155 abnormal WBC Scatter gram flags, 140 Eosinophilia flags and 468 Monocytosis flags were identified.

RESULTS

Considering NRBC and blast flags there was a significant difference between our manual counted and automated counted NRBCs and blasts (P<0.05). There was no significant difference between automated and manual counting of flags for WBC Scatter gram. A significant difference between automated and manual counting data in flags, eosinophilia and monocytosis was foun (P<0.05).

CONCLUSION

We propose the NRBC flags to be ignored and report negative except for the neonatal ward, and the Blasts flags to be ignored and report negative in all the cases. The WBC Scatter gram should be report positive. For eosinophilia and monocytosis flags, we propose, the Sysmex results should be considered correct and the manual checking would not be necessary.

Nucleated red blood cells count in pregnancies with idiopathic intra-uterine growth restriction

OBJECTIVE

Elevated nucleated red blood cell (NRBC) count is introduced as a potential marker of intra-uterine growth restriction (IUGR). To investigate the probable association regardless of any known underlying disease, we aimed to study disturbances in NRBC count in infants experiencing idiopathic IUGR.

MATERIALS AND METHODS

Twenty three infants regarded IUGR without any known cause were chosen to be compared to 48 normal neonates. Blood samples were collected instantly after birth and the same measurements were done in both groups.

RESULTS

NRBC count/100 white blood cells was significantly higher in the IUGR group (P value < 0.001). pH measurements did not reveal any significant difference.

CONCLUSION

Increased NRBC count in cases of idiopathic IUGR in absence of chronic hypoxia could strengthen its predictive value suggested in previous studies. It could help early IUGR detection and beneficial intervention.

Placental pathology and neurological morbidity in preterm infants during the first two weeks after birth

BACKGROUND

The placenta plays a crucial role during pregnancy and dysfunction causes long-term neurological problems. Identifying placenta-related risks for neurological problems shortly after birth may provide clues for early interventions aiming to improve neurological outcome.

OBJECTIVE

To determine the association between placental pathology and neurological morbidity in preterm infants during the first two weeks after birth.

STUDY DESIGN

Placentas of 52 singleton, preterm infants (GA: 25-31weeks, BW: 560-2250 grammes) were examined for histopathology. The infants' neurological condition shortly after birth was determined by assessing the quality of their general movements (GMs): normal, abnormal, or hypokinetic, on days 5, 8, and 15. A motor optimality score (MOS) was also assigned.

RESULTS

Examination of the placentas revealed maternal vascular underperfusion (n=29), ascending intrauterine infection (AIUI) (n=19), villitis of unknown aetiology (n=6), chronic deciduitis (n=11), foetal thrombotic vasculopathy (FTV) (n=9), and elevated nucleated red blood cells (NRBCs) as a marker for foetal hypoxia (n=7). None of the placental lesions were significantly associated with the quality of GMs or MOS.

CONCLUSIONS

This study indicated that placental lesions were not associated with infants' neurological condition as measured by the quality of their general movements during the first two weeks after birth.

Performance and abnormal cell flagging comparisons of three automated blood cell counters: Cell-Dyn Sapphire, DxH-800, and XN-2000

OBJECTIVES

To compare two hematological analyzers-the DxH-800 (DxH; Beckman-Coulter, Miami, FL) and XN-2000 (XN; Sysmex, Kobe, Japan)-with the Cell-Dyn Sapphire (SAPH; Abbott, Santa Clara, CA).

METHODS

We analyzed 4,375 samples. Slide reviews were made in the presence of blast, abnormal lymphocyte, and immature granulocyte (IG) flags or nucleated RBC (NRBC) count.

RESULTS

The analyzers exhibited excellent correlations for CBC and neutrophils but displayed a limit correlation for lymphocytes. The XN did not miss circulating blasts (0.5%-95% in microscopy). For NRBCs, the XN demonstrated a sensitivity of 90%; DxH, 74%; and SAPH, 29%. Only the XN demonstrated a correlation with microscopy, permitting a WBC six-part differential until 15% of NRBCs. The XN and DxH gave useful IG counts with a cutoff less than 5% and a WBC level more than 2,500/mm(3). For abnormal lymphocytes detection, only XN demonstrated sensitivity of more than 95%, but its specificity of 54% requires adaptation.

CONCLUSION

The XN increases the sensitivity of abnormal cell detection compared with the other counters, permitting a seven-part differential between predefined levels, decreasing the slide review from 20% to 9%.

Placental pathology in full-term infants with hypoxic-ischemic neonatal encephalopathy and association with magnetic resonance imaging pattern of brain injury

OBJECTIVE

To investigate the relationship between placental pathology and pattern of brain injury in full-term infants with neonatal encephalopathy after a presumed hypoxic-ischemic insult.

STUDY DESIGN

The study group comprised full-term infants with neonatal encephalopathy subsequent to presumed hypoxia-ischemia with available placenta for analysis who underwent cerebral magnetic resonance imaging (MRI) within the first 15 days after birth. Macroscopic and microscopic characteristics of the placenta were assessed. The infants were classified according to the predominant pattern of brain injury detected on MRI: no injury, predominant white matter/watershed injury, predominant basal ganglia and thalami (BGT) injury, or white matter/watershed injury with BGT involvement. Maternal and perinatal clinical factors were recorded.

RESULTS

Placental tissue was available for analysis in 95 of 171 infants evaluated (56%). Among these 95 infants, 34 had no cerebral abnormalities on MRI, 27 had white matter/watershed injury, 18 had BGT injury, and 16 had white matter/watershed injury with BGT involvement. Chorioamnionitis was a common placental finding in both the infants without injury (59%) and those with white matter/BGT injury (56%). On multinomial logistic regression analysis, white matter/watershed injury with and without BGT involvement was associated with decreased placental maturation. Hypoglycemia was associated with an increased risk of the white matter/BGT injury pattern (OR,5.4; 95% CI, 1.4-21.4). The BGT injury pattern was associated with chronic villitis (OR, 12.7; 95% CI, 2.4-68.7). A placental weight <10th percentile appeared to be protective against brain injury, especially for the BGT pattern (OR, 0.1; 95% CI, 0.01-0.7).

CONCLUSION

Placental weight <10th percentile was mainly associated with normal cerebral MRI findings. Decreased placental maturation and hypoglycemia <2.0 mmol/L were associated with increased risk of white matter/watershed injury with or without BGT involvement. Chronic villitis was associated with BGT injury irrespective of white matter injury.

Unique monoclonal antibodies specifically bind surface structures on human fetal erythroid blood cells

BACKGROUND

Continuing efforts in development of non-invasive prenatal genetic tests have focused on the isolation of fetal nucleated red blood cells (NRBCs) from maternal blood for decades. Because no fetal cell-specific antibody has been described so far, the present study focused on the development of monoclonal antibodies (mAbs) to antigens that are expressed exclusively on fetal NRBCs.

METHODS

Mice were immunized with fetal erythroid cell membranes and hybridomas screened for Abs using a multi-parameter fluorescence-activated cell sorting (FACS). Selected mAbs were evaluated by comparative FACS analysis involving Abs known to bind erythroid cell surface markers (CD71, CD36, CD34), antigen-i, galactose, or glycophorin-A (GPA). Specificity was further confirmed by extensive immunohistological and immunocytological analyses of NRBCs from umbilical cord blood and fetal and adult cells from liver, bone marrow, peripheral blood, and lymphoid tissues.

RESULTS

Screening of 690 hybridomas yielded three clones of which Abs from 4B8 and 4B9 clones demonstrated the desired specificity for a novel antigenic structure expressed on fetal erythroblast cell membranes. The antigenic structure identified is different from known surface markers (CD36, CD71, GPA, antigen-i, and galactose), and is not present on circulating adult erythroid cells, except for occasional detectability in adult bone marrow cells.

CONCLUSIONS

The new mAbs specifically bind the same or highly overlapping epitopes of a surface antigen that is almost exclusively expressed on fetal erythroid cells. The high specificity of the mAbs should facilitate development of simple methods for reliable isolation of fetal NRBCs and their use in non-invasive prenatal diagnosis of fetal genetic status.