ABSTRACT
Objectives: Giant inclusions in leukocytes is a common feature that can be observed in some infections but can be also related to rare genetic disorders such as Chédiak-Higashi syndrome (CHS). A differential diagnosis between these groups of diseases has to be performed using specific genetic tests. Clinical and pathological history is relevant for a diagnostic orientation due to the difficulty and specificity of the diagnostic confirmation. Case presenation: We present the case of a 3-years-old male patient with recurrent respiratory infections. It is important to highlight the presence of a lock of white hair on the front of the head and some hypopigmentation of the skin. In the blood smear, the presence of big cytoplasm granules in all the leukocytes, especially in neutrophils. Conclusions: CHS is an uncommon genetic disorder caused by the mutation in the LYST gene situated in chromosome 1q42.3 which codified for LYST protein. Molecular genetic testing also can be done to detect the biallelic variants in the LYST gene. It is essential to perform peripheral blood smears in the presence of changes in quantitative and/or qualitative values in the complete blood count as a first step in the diagnosis algorithm.
ABSTRACT
Efficiency and accuracy in automated hematology analyzers are very important for clinical laboratories. The purpose was to evaluate the flags and results reported by the newest Beckman Coulter analyzer DxH 900 compared to the Sysmex XN20 system. Samples were analyzed on the XN20 (Sysmex, Kobe, Japan) and on the Beckman Coulter DxH 900 (Beckman Coulter, Miami, Florida, USA). Slide reviews were performed microscopically. Morphologic criteria were used to identify abnormal cells as recommended by International Consensus Group for Hematology (ICSH): blasts, immature granulocytes (IG%), abnormal lymphocytes (ALs) and plasma cells. Results: there was a strong correlation between the analyzers in almost all clinical parameters tested. Both DxH 900 and XN20 showed an excellent degree of association for the leukocyte differential compared to the reference method (manual microscopy). When it comes to IG%, XN20 showed a positive bias for higher results. Related to platelets, there are no differences between the two methods for PLT count. For mean platelet volume (MPV), DxH 900 provided 100% results of the samples analyzed while XN20 while in the XN20 analyzer, 16% of the results were missing. From our results we came to the conclusion that both analyzers, DxH 900 and XN20 were clinically accurate and efficient. Abnormal Lymphocyte detection highlighted the differences between the two technologies as only minimal agreement was obtained. DxH 900 demonstrated higher sensitivity in detecting IG with good correlation with microscopic review. The DxH 900 for platelet clumps identification provides an excellent flag (PLT Clumps) with the highest sensitivity observed in our evaluation.
ABSTRACT
The high infectivity of SARS-CoV-2 makes it essential to develop a rapid and accurate diagnostic test so that carriers can be isolated at an early stage. Viral RNA in nasopharyngeal samples by RT-PCR is currently considered the reference method although it is not recognized as a strong gold standard due to certain drawbacks. Here we develop a methodology combining the analysis of from human nasopharyngeal (NP) samples by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) with the use of machine learning (ML). A total of 236 NP samples collected in two different viral transport media were analyzed with minimal sample preparation and the subsequent mass spectra data was used to build different ML models with two different techniques. The best model showed high performance in terms of accuracy, sensitivity and specificity, in all cases reaching values higher than 90%. Our results suggest that the analysis of NP samples by MALDI-TOF MS and ML is a simple, safe, fast and economic diagnostic test for COVID-19.
