COMMENT ON THIS CLINICAL CASE

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Aspergillose cérébrale traitée avec succès par voriconazole chez un patient immunodéprimé

Cerebral aspergillosis is a severe invasive mycosis occurring in immunocompromised patients. This pathology is associated with a high rate of mortality and is a current complication of pulmonary invasive aspergillosis. We report the case of a 44-year-old immunocompromised male with a recent history of oropharyngeal carcinoma. At his admission the patient presented with fever and confusion. Imaging revealed the presence of a cerebral abscess combined with lung infiltrates. During hospitalization and despite a broad-spectrum antibiotic regimen his condition worsened. A thin needle aspiration of the abscess was performed for diagnosis purpose. Histological examination of the tissue showed septate and branched hyphae with 45° angles suggestive of Aspergillus. A real-time PCR specific for the detection of Aspergillus sp. was carried out and confirmed the fungal etiology of the abscess. Rare colonies of A. fumigatus were isolated a few days later. The diagnosis of invasive pulmonary aspergillosis complicated by a cerebral dissemination was confirmed. Antifungal treatment based on voriconazole 4 mg/kg q12h was introduced and the dosage was successfully increased up to 5 mg/kg q12h by drug monitoring. This case highlights the usefulness of the Aspergillus PCR for the rapid identification of hyphae in tissue biopsies (or in the event of negative culture), and the importance of therapeutic drug monitoring in treatment by voriconazole

Evaluation of the Sysmex XE-5000 for automated body fluid and cerebrospinal fluid analysis

peer reviewedLe mode d’analyse des liquides de ponction du Sysmex XE-5000 a été évalué sur 159 liquides de ponction, dont 60 liquides céphalorachidiens. La numération érythrocytaire et leucocytaire a été comparée aux comptages réalisés en microscopie en chambre de Fuchs-Rosenthal. La différentiation des cellules monucléées et polynucléées par le XE-5000 a été comparée à la formule manuelle obtenue sur lames de cytocentrifugation. Une bonne corrélation a été obtenue entre le XE-5000 et la technique manuelle avec des coefficients de corrélation supérieurs à 0,8 pour la numération des érythrocytes et des leucocytes ainsi que pour la différenciation leucocytaire pour la plupart des liquides de ponction. La limite de sensibilité fonctionnelle (c’est-à-dire une précision intra-série supérieure à 20 %) a été atteinte pour des numérations érythrocytaires inférieures à 400/ L et leucocytaires inférieures à 30/ L. La contamination inter-échantillons est négligeable et la linéarité est satisfaisante jusqu’à 400 érythrocytes/ L et 30 leucocytes/ L. Ces résultats montrent que l’analyse automatisée des liquides de ponction par le XE-5000 est une alternative acceptable à la technique microscopique de référence aussi bien pour la numération érythrocytaire et leucocytaire que pour la différenciation des cellules polymorphonucléées et mononucléées pour la majorité des liquides de ponction y compris les liquides céphalorachidiens. The body fluid mode on the Sysmex XE-5000 automated hematology analyzer was evaluated on 99 body fluids and 60 cerebrospinal fluids. Erythrocyte and leukocyte numeration was compared to microscopic counts on Fuchs-Rosenthal chambers. Differentiation of mononuclear (MN) and polymorphonuclear (PMN) cells on the XE-5000 was compared to manual differential on cytospin slides. A good agreement was found between the XE-5000 and the manual method with correlation coefficients more than 0.8 for erythrocyte counts, leukocyte counts and leukocyte differentiation in most types of body fluids. The functional sensitivity limit (i.e., within run precision more than 20%) was reached for red blood cell counts more than 400/ L and white blood cell counts more than 30/ L. Carry over was negligible and linearity was adequate for as low as 400 erythrocytes/ L and 30 leucocytes/ L. Our results demonstrate that the automated body fluid analysis on the XE-5000 is an acceptable alternative to the microscopic reference method for erythrocyte and leukocyte numeration as well as MN and PMN differential for most body fluids including cerebrospinal fluids

Nationwide Harmonization Effort for Semi-Quantitative Reporting of SARS-CoV-2 PCR Test Results in Belgium.

From early 2020, a high demand for SARS-CoV-2 tests was driven by several testing indications, including asymptomatic cases, resulting in the massive roll-out of PCR assays to combat the pandemic. Considering the dynamic of viral shedding during the course of infection, the demand to report cycle threshold (Ct) values rapidly emerged. As Ct values can be affected by a number of factors, we considered that harmonization of semi-quantitative PCR results across laboratories would avoid potential divergent interpretations, particularly in the absence of clinical or serological information. A proposal to harmonize reporting of test results was drafted by the National Reference Centre (NRC) UZ/KU Leuven, distinguishing four categories of positivity based on RNA copies/mL. Pre-quantified control material was shipped to 124 laboratories with instructions to setup a standard curve to define thresholds per assay. For each assay, the mean Ct value and corresponding standard deviation was calculated per target gene, for the three concentrations (10, 10 and 10 copies/mL) that determine the classification. The results of 17 assays are summarized. This harmonization effort allowed to ensure that all Belgian laboratories would report positive PCR results in the same semi-quantitative manner to clinicians and to the national database which feeds contact tracing interventions