A prolonged microscopic observation improves detection of underpopulated cells in peripheral blood smears.

We evaluated an extended time in the microscopic review in samples in which the potential clinical information could be increased with respect to those that could be achieved with the usual laboratory methodologies. We used samples containing nucleated red blood cells in a small amount and cytopenic samples. For these purposes for each peripheral blood smear, the timing of eye-count differential was increased up to 20 min, regardless of the final number of cells which could be counted. In addition, an automated system for digital analysis of peripheral blood smears was employed and the number of cells counted was brought up to 1000 leukocytes. In both manual and automatic light microscopy extended observation, we obtained more diagnostic information in respect to those with routine or standard methods. Both automated and manual increase systems of the timing for microscopic review are useful tools to find diagnostic information that otherwise would be lost using normal and standard procedures. So, these methods should be used especially when there is a higher pre-test probability for discovery of pathological cells.

Detection of Apoptotic Lymphocytes Through Sysmex XN-1000 As a Diagnostic Marker for Mononucleosis Syndrome.

BACKGROUND: The infectious mononucleosis (IM) includes clue elements, apoptotic and atypical lymphocytes. In IM, the evaluation of dot plot provided by Sysmex XN-1000 analyzer revealed a stretched lymphocytic cluster, white cell differential channel (WDF), on cytogram. METHODS: In this study, we analyzed 698 samples that include 39 IM, 76 chronic lymphoproliferative disorders, 25 nonclonal lymphocytosis, and 40 healthy donors. Five hundred eighteen samples with other diseases or interference were evaluated. The algorithm was validated on 40,000 files that were received from internal database of Sysmex-Dasit. RESULTS: The analysis of flow cytometry standard (FCS) files in WDF channel and presumed apoptotic lymphocytes counts on side scatter/forward scatter (SSC/FSC) and SSC/SFL (where SFL is side fluorescence) dot plot revealed excellent correlation among apoptotic cells on peripheral blood smear (R(2)  = 0.79 and 0.75). There was a variation of positional parameters in lymphocyte clusters WX, WY, and WZ. If WX-SSC > 500 and WY-SFL > 1,000 and WZ-FSC > 700, specificity equals to 99% and sensitivity equals to 100%. If nucleated red blood cell (NRBC) <0.03 × 10(3) /µl, specificity equals to 100%. In received files, positives were 1% adding the simultaneous presence of a percentage of events in the two gates relating to the apoptotic lymphocytes of 1.2% of WBC. CONCLUSION: On Sysmex XN-1000, dot-plot observation allowed immediate detection of IM. Meanwhile, an algorithm based on the parameters on these plots can be calculated with excellent performance.

Severe high-molecular-weight kininogen deficiency: clinical characteristics, deficiency-causing KNG1 variants, and estimated prevalence.

BACKGROUND: Severe high-molecular-weight kininogen (HK) deficiency is a poorly studied autosomal recessive contact system defect caused by pathogenic, biallelic KNG1 variants. AIM: We performed the first comprehensive analysis of diagnostic, clinical, genetic, and epidemiological aspects of HK deficiency. METHODS: We collected clinical information and blood samples from a newly detected HK-deficient individual and from published cases identified by a systematic literature review. Activity and antigen levels of coagulation factors were determined. Genetic analyses of KNG1 and KLKB1 were performed by Sanger sequencing. The frequency of HK deficiency was estimated considering truncating KNG1 variants from GnomAD. RESULTS: We identified 48 cases of severe HK deficiency (41 families), of these 47 have been previously published (n = 19 from gray literature). We genotyped 3 cases and critically appraised 10 studies with genetic data. Ten HK deficiency-causing variants (one new) were identified. All of them were truncating mutations, whereas the only known HK amino acid substitution with a relevant phenotype instead causes hereditary angioedema. Conservative estimates suggest an overall prevalence of severe HK deficiency of approximately one case per 8 million population, slightly higher in Africans. Individuals with HK deficiency appeared asymptomatic and had decreased levels of prekallikrein and factor XI, which could lead to misdiagnosis. CONCLUSION: HK deficiency is a rare condition with only few known pathogenic variants. It has an apparently good prognosis but is prone to misdiagnosis. Our understanding of its clinical implications is still limited, and an international prekallikrein and HK deficiency registry is being established to fill this knowledge gap.

Mindray BC-6800 haematological analyser: 3D-DIFF scattergram usefulness in infectious mononucleosis diagnosis.

INTRODUCTION: 3D-DIFF scattergram of the Mindray BC-6800 haematological analyser shows morphological abnormalities and lymphocyte cluster splitting related to the presence of reactive lymphocytes. This study aims to assess whether these cytographic changes are useful in detecting both activated and apoptotic lymphocytes, leading to an improvement in the laboratory diagnostic process of infectious mononucleosis. METHODS: Two hundred three samples with modified shape and doubled lymphocyte cluster of DIFF scattergram (study group) were divided into two different subgroups: with and, respectively, without serological evidence of ongoing IM. Activated and apoptotic cells in peripheral blood were counted by light microscopy or gating in the instrumental dot plots. Values of apoptotic cells counted by microscopy were compared with those resulting from gating. RESULTS: Samples with both shape change and doubled lymphocyte cluster had serological profiles according to the diagnosis of ongoing infectious mononucleosis. Blood smears review was positive for reactive lymphocytes in all 112 samples (100%). An underestimation of apoptotic cell count by light microscopy compared with the gating in the instrumental scatterplot was also observed (96 out of 112, 85.7%). CONCLUSION: The additional lymphocyte cluster was significantly associated with activated and apoptotic lymphocytes in samples with serology suggesting ongoing infectious mononucleosis. Considering the significance of clue for infectious mononucleosis assigned to the apoptotic lymphocytes, a specific flag such as "apoptotic cells?" could be associate with the related cluster. Such a flag could be used for dedicated rules for smears review, thus increasing infectious mononucleosis detection in laboratories that do not usually practise instrumental cytograms observation.

The diagnostic use of ADVIA 2120i Siemens and an "APL criteria" can help to reduce the rate of early death in the APL.

INTRODUCTION: Acute promyelocytic leukemia (APL) is a type of acute myeloid leukemia (AML) with a life-threatening coagulopathy. Once it is suspected, ATRA should be started. Appreciation of APL details is critical, but an experienced hematopathologist may not be available. We developed an algorithm, based on the parameters generated by automated blood cell counter ADVIA 2120i Siemens that can aid the diagnosis of APL. METHODS: All parameters in the algorithm were selected on the bases of the pathophysiology of the APL and the analyzer's technology. We used c1 cutoff: PLT < 150 × 103 ; % Mono<10; % LUC<4; % hyperchromic cells > 2; %saturated cells ≥ 1; % blasts > 4. Satisfying at least five of six cutoffs, we obtained an "APL criteria". It was tested on 247.209 raw-data from routine and emergency samples and on 124 raw-data from APL. We performed a multiparametric analyses and obtained definitive cutoffs (c2). It was validated on a new group of 51.002 raw-data from routine and emergency. Finally, it was tested on AML and ALL, MDS, MPN, oncologic samples, and hemolytic and megaloblastic anemia. RESULTS: The algorithm provided a high sensitivity (86.30%) and high specificity (99.83%) in APL with high or normal number of WBC and satisfactory results in APL with cytopenia (80%). The specificity was very high also in groups of hematological and nonhematological diseases. It can be used as an "APL criteria" to alert pathologists of the possible presence of APL. It together with instrumental and classical morphology may allow to reduce the time of diagnosis with further reduction in early death.

Automatic wedge smears preparation may cause traumatic morphological changes in peripheral blood cells.

In recent years, several automated analysers that prepare and stain blood smears have been introduced in clinical laboratories. Despite the use of instrumental settings based on physical characteristic of individual samples, traumatic injuries of neutrophil and lymphocytes can be observed. Some samples present a very high percentage of damaged cells, allowing the speculation that a cellular susceptibility may enhance mechanical traumatism. These artefacts can puzzle morphological evaluation in both traditional and digitised microscopy; in addition, unskilled operators can be misled.

Short preheating at 41°C leads to a red blood cells count comparable to that in RET channel of Sysmex analysers in samples showing cold agglutination.

AIMS: The presence of cold agglutinin in blood samples can cause a spontaneous agglutination of red blood cells (RBCs) when low temperature occurs. This phenomenon causes a spurious lowering of RBC count on the automated haematological analysers that are detected by incongruous values (≥370 g/L) of the mean cellular haemoglobi concentration (MCHC). A preheating at 37°C can remove the RBC agglutination generally resulting in a reliable count. It has been reported that the same result can be reached by using the optical reticulocyte (RET) channel of Sysmex analysers where the RBC count is not influenced by the presence of cold agglutinin. This study aims to evaluate these data in a larger population, with regard to environmental conditions on Sysmex analysers. We have also evaluated the influence of different thermal pretreatments on the RBC count. METHODS: This study was performed on 96 remnants of peripheral blood samples (48 with MCHC in normal range and 48 with MCHC>370 g/L) which have been analysed in different preanalytical conditions on the Sysmex analysers. RESULTS: A preheating of samples at 41°C for 1 min leads to a reversibility of the cold agglutination comparable to the one observed in the RET channel and yields better results compared with 37°C for 2 hours. CONCLUSIONS: None of described procedures assure the complete cold agglutination reversibility in every case. Consequently, since the haematological analysers not yet provide reliable parameters to confirm the complete resolution of agglutination, further verification of RBC count accuracy needs to be performed.