Plasma Apolipoprotein Concentrations Are Highly Altered in Severe Intensive Care Unit COVID-19 Patients: Preliminary Results from the LIPICOR Cohort Study.

SARS-CoV-2 infection goes beyond acute pneumonia, as it also impacts lipid metabolism. Decreased HDL-C and LDL-C levels have been reported in patients with COVID-19. The lipid profile is a less robust biochemical marker than apolipoproteins, components of lipoproteins. However, the association of apolipoprotein levels during COVID-19 is not well described and understood. The objective of our study is to measure plasma levels of 14 apolipoproteins in patients with COVID-19 and to evaluate the relationships between apolipoprotein levels, severity factors and patient outcomes. From November to March 2021, 44 patients were recruited on admission to the intensive care unit because of COVID-19. Fourteen apolipoproteins and LCAT were measured by LC-MS/MS in plasma of 44 COVID-19 patients on admission to the ICU and 44 healthy control subjects. Absolute apolipoprotein concentrations were compared between COVID-19 patients and controls. Plasma apolipoproteins (Apo) A (I, II, IV), C(I, II), D, H, J and M and LCAT were lower in COVID-19 patients, whereas Apo E was higher. COVID-19 severity factors such as PaO2/FiO2 ratio, SO-FA score and CRP were correlated with certain apolipoproteins. Lower Apo B100 and LCAT levels were observed in non-survivors of COVID-19 versus survivors. To conclude, in this study, lipid and apolipoprotein profiles are altered in COVID-19 patients. Low Apo B100 and LCAT levels may be predictive of non-survival in COVID-19 patients.

Low HDL-Cholesterol Concentrations in Lung Transplant Candidates are Strongly Associated With One-Year Mortality After Lung Transplantation.

High-density lipoproteins (HDLs), whose main role is the reverse transport of cholesterol, also have pleiotropic anti-inflammatory, antioxidant, anti-apoptotic and anti-infectious properties. During sepsis, HDL cholesterol (HDL-C) concentration is low, HDL particle functionality is altered, and these modifications are correlated with poor outcomes. Based on the protective effects of HDL, we hypothesized that HDL-C levels could be associated with lung transplantation (LT) outcome. We thus looked for an association between basal HDL-C concentration and one-year mortality after LT. In this single-center prospective study including consecutive LTs from 2015 to 2020, 215 patients were included, essentially pulmonary fibrosis (47%) and chronic obstructive pulmonary disease (COPD) (38%) patients. Mortality rate at one-year was 23%. Basal HDL-C concentration stratified nonsurvivors to survivors at one-year (HDL-C = 1.26 [1.12-1.62] mmol/L vs. HDL-C = 1.55 [1.22-1.97] mmol/L, p = 0.006). Multivariate analysis confirmed that HDL-C concentration during the pretransplant assessment period was the only variable inversely associated with mortality. Moreover, mortality at one-year in patients with HDL-C concentrations ≤1.45 mmol/L was significantly higher (log-rank test, p = 0.00085). In conclusion, low basal HDL-C concentrations in candidates for LT are strongly associated with mortality after LT. To better understand this association, further studies in this field are essential and, in particular, a better characterization of HDL particles seems necessary.

Relationship between liver dysfunction, lipoprotein concentration and mortality during sepsis.

BACKGROUND: High-density lipoproteins (HDLs) are synthesized by the liver and display endothelioprotective properties, including anti-inflammatory, antiapoptotic, antithrombotic and antioxidant effects. In both septic and chronic liver failure patients, a low HDL cholesterol (HDL-C) concentration is associated with overmortality. Whereas sepsis-associated liver dysfunction is poorly defined, the aim of this study was to characterize the relationship between liver dysfunction, lipoprotein concentrations and mortality in septic patients in the intensive care unit (ICU). METHODS: A prospective observational study was conducted in a university hospital ICU. All consecutive patients admitted for septic shock or sepsis were included. Total cholesterol, HDL-C, low-density lipoprotein-cholesterol (LDL-C), and triglyceride levels were assessed at admission. Sepsis-associated liver dysfunction was defined as a serum bilirubin≥ 2N or aspartate aminotransferase/alanine aminotransferase concentrations ≥ 2N. Short-term and one-year prognostic outcomes were prospectively assessed. RESULTS: A total of 219 septic patients were included, and 15% of them presented with sepsis-associated liver dysfunction at admission. Low concentrations of lipoproteins were associated with mortality at Day 28 in the overall population. Sepsis-associated liver dysfunction at admission was associated with overmortality. In this subgroup, patients had a lower HDL-C concentration than patients without hepatic dysfunction (HDL-C = 0.31 [0.25, 0.55] mmol/L vs. 0.48 [0.29, 0.73] mmol/L, p = 0.0079) but there was no relationship with the outcome. Interestingly, no correlation was observed between lipoprotein concentrations and liver dysfunction markers. CONCLUSION: Sepsis-associated liver dysfunction at ICU admission is strongly associated with overmortality and is associated with a lower HDL-C concentration. However, in this subgroup of patients, HDL-C concentration had no relationship with mortality. Further exploratory studies are needed to better understand the interaction between lipoproteins and liver dysfunction during sepsis.

Performance evaluation of the high sensitive troponin I assay on the Atellica IM analyser.

Introduction: The Fourth Universal Definition of Myocardial Infarction Global Taskforce recommends the use of high sensitive troponin (hs-Tn) assays in the diagnosis of acute myocardial infarction. We evaluated the analytical performance of the Atellica IM High-sensitivity Troponin I Assay (hs-TnI) (Siemens Healthcare Diagnostics Inc., Tarrytown, USA) and compared its performance to other hs-TnI assays (Siemens Advia Centaur, Dimension Vista, Dimension EXL, and Abbott Architect (Wiesbaden, Germany)) at one or more sites across Europe. Materials and methods: Precision, detection limit, linearity, method comparison, and interference studies were performed according to Clinical and Laboratory Standards Institute protocols. Values in 40 healthy individuals were compared to the manufacturer's cut-offs. Sample turnaround time (TAT) was examined. Results: Imprecision repeatability CVs were 1.1-4.7% and within-lab imprecision were 1.8-7.6% (10.0-25,000 ng/L). The limit of blank (LoB), detection (LoD), and quantitation (LoQ) aligned with the manufacturer's values of 0.5 ng/L, 1.6 ng/L, and 2.5 ng/L, respectively. Passing-Bablok regression demonstrated good correlations between Atellica IM analyser with other systems; some minor deviations were observed. All results in healthy volunteers fell below the 99th percentile URL, and greater than 50% of each sex demonstrated values above the LoD. No interference was observed for biotin (≤ 1500 µg/L), but a slight bias at 5.0 g/L haemoglobin and 50 ng/L Tn was observed. TAT from was fast (mean time = 10.9 minutes) and reproducible (6%CV). Conclusions: Real-world analytical and TAT performance of the hs-TnI assay on the Atellica IM analyser make this assay fit for routine use in clinical laboratories.

First Recombinant High-Density Lipoprotein Particles Administration in a Severe ICU COVID-19 Patient, a Multi-Omics Exploratory Investigation.

High-density lipoproteins (HDLs) have multiple endothelioprotective properties. During SARS-CoV-2 infection, HDL-cholesterol (HDL-C) concentration is markedly reduced, and studies have described severe impairment of the functionality of HDL particles. Here, we report a multi-omic investigation of the first administration of recombinant HDL (rHDL) particles in a severe COVID-19 patient in an intensive care unit. Plasma ApoA1 increased and HDL-C decreased after each recombinant HDL injection, suggesting that these particles were functional in terms of reverse cholesterol transport. The proportion of large HDL particles also increased after injection of recombinant HDL. Shotgun proteomics performed on HDLs isolated by ultracentrifugation indicated that ApoA1 was more abundant after injections whereas most of the pro-inflammatory proteins identified were less abundant. Assessment of Serum amyloid A-1, inflammatory markers, and cytokines showed a significant decrease for most of them during recombinant HDL infusion. Our results suggest that recombinant HDL infusion is feasible and a potential therapeutic strategy to be explored in COVID-19 patients.

Lipoprotein concentration in patients requiring extracorporeal membrane oxygenation.

Extracorporeal membrane oxygenation (ECMO), a relevant technology for patients with acute respiratory distress syndrome (ARDS) or acute cardiac failure (ACF), is a frequent cause of systemic inflammatory response syndrome. During sepsis, HDL cholesterol (HDL-C) and LDL cholesterol (LDL-C) concentrations decrease, and an association between low lipoprotein levels and poor outcomes was reported. There are no data from patients undergoing ECMO. The goal of this study was to characterize the lipoprotein profiles of ICU patients requiring ECMO. All consecutive patients admitted for ARDS or ACF requiring ECMO were prospectively included. Daily lipoprotein levels and short-term prognosis outcome were assessed. 25 patients were included. On admission, lipoprotein concentrations were low, under the reference values ([HDL-C] = 0.6[0.4-0.8]mmol/L;[LDL-C] = 1.3[1.0-1.7]mmol/L). A statistically significant rise in lipoproteins overtime was observed during the ICU stay. We found no relationship between lipoproteins concentrations and mortality on Day-28 (p = 0.689 and p = 0.979, respectively). Comparison of surviving patients with non-surviving patients did not reveal any differences in lipoproteins concentrations. Stratification between septic and non-septic patients demonstrated that septic patients had lower lipoproteins concentrations on admission (HDL-C: 0.5[0.3-0.6]mmol/l vs 0.8[0.6-0.9]mmol/l, p = 0.003; LDL-C: 1.1[0.9-1.5]mmol/l vs 1.5[1.3-2.6]mmol/l; p = 0.012), whereas these two groups were comparable in terms of severity and outcomes. HDL-C concentrations during ICU hospitalization were also significantly lower in the septic group than in the non-septic group (p = 0.035). In conclusion, Lipoprotein concentrations are low in patients requiring ECMO but are not associated with poor outcomes. The subpopulation of septic patients had lower lipoprotein levels overtime, which reinforces the potential key-role of these particles during sepsis.

Altered high-density lipoprotein composition and functions during severe COVID-19.

Coronavirus disease 2019 (COVID-19) pandemic is affecting millions of patients worldwide. The consequences of initial exposure to SARS-CoV-2 go beyond pulmonary damage, with a particular impact on lipid metabolism. Decreased levels in HDL-C were reported in COVID-19 patients. Since HDL particles display antioxidant, anti-inflammatory and potential anti-infectious properties, we aimed at characterizing HDL proteome and functionality during COVID-19 relative to healthy subjects. HDLs were isolated from plasma of 8 severe COVID-19 patients sampled at admission to intensive care unit (Day 1, D1) at D3 and D7, and from 16 sex- and age-matched healthy subjects. Proteomic analysis was performed by LC-MS/MS. The relative amounts of proteins identified in HDLs were compared between COVID-19 and controls. apolipoprotein A-I and paraoxonase 1 were confirmed by Western-blot analysis to be less abundant in COVID-19 versus controls, whereas serum amyloid A and alpha-1 antitrypsin were higher. HDLs from patients were less protective in endothelial cells stiumalted by TNFα (permeability, VE-cadherin disorganization and apoptosis). In these conditions, HDL inhibition of apoptosis was blunted in COVID-19 relative to controls. In conclusion, we show major changes in HDL proteome and decreased functionality in severe COVID-19 patients.

Relationship between lipoprotein concentrations and short-term and 1-year mortality in intensive care unit septic patients: results from the HIGHSEPS study.

BACKGROUND: High-density lipoproteins (HDLs), particles characterized by their reverse cholesterol transport function, display pleiotropic properties, including anti-inflammatory and antioxidant functions. Moreover, all lipoproteins (HDLs but also low-density lipoproteins (LDLs)) neutralize lipopolysaccharides, leading to increased bacterial clearance. These two lipoproteins decrease during sepsis, and an association between low lipoprotein levels and poor outcome was reported. The goals of this study were to characterize the lipid profile of septic patients hospitalized in our intensive care unit (ICU) and to determine the relationship with the outcome. METHODS: A prospective observational study was conducted in a university hospital ICU. All consecutive patients admitted for septic shock or sepsis were included. Total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglyceride levels were assessed at admission (day 1), at day 3, and at ICU discharge. When available, a prehospitalization lipid profile collected prior to the patient's hospitalization was compiled. Short-term and 1-year prognostic outcomes were prospectively assessed. RESULTS: A total of 205 patients were included. We found a decrease in HDL-C concentration between previous values and those at admission, followed by an additional decrease at day 3. At ICU discharge, the concentration was higher than that at day 3 but did not reach the concentration measured prior to hospitalization (prior HDL-C = 1.22 (1.04-1.57) mmol/l; day 1 HDL-C = 0.44 (0.29-0.70) mmol/l; day 3 HDL-C = 0.30 (0.25-0.48) mmol/l; and HDL-C at discharge = 0.65 (0.42-0.82) mmol/l). A similar trend was found for LDL-C (prior LDL-C = 2.7 (1.91-3.33) mmol/l; day 1 LDL-C = 1.0 (0.58-1.50) mmol/l; day 3 LDL-C = 1.04 (0.64-1.54) mmol/l; and LDL-C at discharge = 1.69 (1.26-2.21) mmol/l). Mixed models for repeated measures of lipoprotein concentrations showed a significant difference in HDL-C and LDL-C concentrations over time between survivors and nonsurvivors at day 28. An HDL-C concentration at admission of less than 0.4 mmol/l was associated with increased mortality at day 28 (log-rank test, p = 0.034) but not at 1 year (log-rank test, p = 0.24). An LDL-C concentration at admission of less than 0.72 mmol/l was associated with increased mortality at day 28 and at 1 year (log-rank test, p < 0.001 and p = 0.007, respectively). No link was found between prior lipid profile and mortality. CONCLUSIONS: We showed no relationship between the prehospitalization lipid profile and patient outcome, but low lipoprotein levels in the ICU were strongly associated with short-term mortality.

Lipoprotein concentrations over time in the intensive care unit COVID-19 patients: Results from the ApoCOVID study.

INTRODUCTION: Severe acute respiratory syndrome coronavirus2 has caused a global pandemic of coronavirus disease 2019 (COVID-19). High-density lipoproteins (HDLs), particles chiefly known for their reverse cholesterol transport function, also display pleiotropic properties, including anti-inflammatory or antioxidant functions. HDLs and low-density lipoproteins (LDLs) can neutralize lipopolysaccharides and increase bacterial clearance. HDL cholesterol (HDL-C) and LDL cholesterol (LDL-C) decrease during bacterial sepsis, and an association has been reported between low lipoprotein levels and poor patient outcomes. The goal of this study was to characterize the lipoprotein profiles of severe ICU patients hospitalized for COVID-19 pneumonia and to assess their changes during bacterial ventilator-associated pneumonia (VAP) superinfection. METHODS: A prospective study was conducted in a university hospital ICU. All consecutive patients admitted for COVID-19 pneumonia were included. Lipoprotein levels were assessed at admission and daily thereafter. The assessed outcomes were survival at 28 days and the incidence of VAP. RESULTS: A total of 48 patients were included. Upon admission, lipoprotein concentrations were low, typically under the reference values ([HDL-C] = 0.7[0.5-0.9] mmol/L; [LDL-C] = 1.8[1.3-2.3] mmol/L). A statistically significant increase in HDL-C and LDL-C over time during the ICU stay was found. There was no relationship between HDL-C and LDL-C concentrations and mortality on day 28 (log-rank p = 0.554 and p = 0.083, respectively). A comparison of alive and dead patients on day 28 did not reveal any differences in HDL-C and LDL-C concentrations over time. Bacterial VAP was frequent (64%). An association was observed between HDL-C and LDL-C concentrations on the day of the first VAP diagnosis and mortality ([HDL-C] = 0.6[0.5-0.9] mmol/L in survivors vs. [HDL-C] = 0.5[0.3-0.6] mmol/L in nonsurvivors, p = 0.036; [LDL-C] = 2.2[1.9-3.0] mmol/L in survivors vs. [LDL-C] = 1.3[0.9-2.0] mmol/L in nonsurvivors, p = 0.006). CONCLUSION: HDL-C and LDL-C concentrations upon ICU admission are low in severe COVID-19 pneumonia patients but are not associated with poor outcomes. However, low lipoprotein concentrations in the case of bacterial superinfection during ICU hospitalization are associated with mortality, which reinforces the potential role of these particles during bacterial sepsis.

Multi-centre evaluation of recent troponin assays for the diagnosis of NSTEMI.

OBJECTIVES: We aimed to compare the use of nine different cardiac troponin (cTn) assays (2 cTnT and 7 cTnI) for the diagnosis of NSTEMI in a single multi-centre population. DESIGN AND METHODS: One hundred and fifty-eight patients were included (mean age 60 years, SD 17 years), including 23 patients (14%) with NSTEMI. RESULTS: The analytical comparison highlighted a large heterogeneity of cTn assays, as reflected by percentages of patients with detectable cTn, correlation coefficients, Passing-Bablok comparisons and concordance coefficients. Correlations within cTnI assays were good and correlation within cTnT assays was excellent. Diagnostic performances demonstrated that each cTn assay has specific threshold values. Furthermore, some assays (HS-cTnI and T, cTnI-Pathfast and cTnI-Centaur) indicated high sensitivity and negative predictive value using the limit of detection (LoD) diagnostic strategy. For the latter assays, a significant increase in specificity was found when using the 99th percentile or the H0-H3 strategies, in comparison to the LoD strategy. When applying the European Society of Cardiology H0-H3 algorithm, comparable diagnostic performances were obtained. CONCLUSION: All 9 cTn assays indicated overall good diagnostic performances for the diagnosis of NSTEMI in emergency departments when the recommended algorithm based on the variation of cTn value between two measurements at admission and 3 h later was used.

Impact of Fetuin-A on progression of calcific aortic valve stenosis - The COFRASA - GENERAC study.

BACKGROUND: Aortic stenosis (AS) is an active disease, but the determinants of AS progression remain largely unknown. Low levels of Fetuin-A, a powerful inhibitor of ectopic calcification, have been linked to ectopic calcium tissue deposition but its role in AS progression has not been clearly evaluated. METHODS: In our ongoing prospective cohort (COFRASA/GENERAC), serum Fetuin-A level was measured at baseline and AS severity was evaluated at baseline and yearly thereafter using echocardiography (mean pressure gradient (MPG)) and computed tomography (degree of aortic valve calcification (AVC)). Annual progression was calculated as [(final measurement-baseline measurement)/follow-up duration] for both MPG and AVC measurements. RESULTS: We enrolled 296 patients (74 ±â€¯10 years,73% men); mean follow-up duration was 3.0 ±â€¯1.7 years. No correlation was found between baseline serum Fetuin-A (0.55 ±â€¯0.15 g/L) and baseline AS severity (r = 0.25, p = 0.87 for MPG; r = 0.06, p = 0.36 for AVC). More importantly, there was no correlation between baseline serum Fetuin-A level and AS progression either assessed using MPG or AVC (both r = 0.01, p = 0.82). In bivariate analysis, after adjustment for age, gender, baseline AS severity, or valve anatomy, Fetuin-A was not associated with AS progression (all p > 0.20). The absence of link with AS progression was further confirmed by the absence of link betwen serum Fetuin-A and the occurrence of AS-related events (p = 0.17). CONCLUSIONS: In a large prospective cohort of AS patients, serum Fetuin-A was not associated to hemodynamic or anatomic AS progression. Despite its capacity to inhibit ectopic calcium deposition, Fetuin-A serum level seemed to have minor influence on AS progression.

Effect of a Red Blood Cell Transfusion on Biological Markers Used to Determine the Cause of Anemia: A Prospective Study.

BACKGROUND: Blood test results required for the evaluation of anemia are considered difficult to interpret after red blood cell transfusion. However, this hypothesis is neither supported by a strong physiological rationale nor is it evidence based. METHODS: We conducted a prospective multicenter study to compare the values of key assays prior to and after a course of red blood cell transfusion in the emergency or internal medicine units in 4 university hospitals. The following parameters were measured prior to and within 48 to 72 hours after transfusion: complete blood count with reticulocyte count, direct Coombs' test, ferritin, transferrin saturation, soluble transferrin receptor, serum and erythrocyte folate, cobalamin, lactate dehydrogenase, bilirubin, haptoglobin, and C-reactive protein. We investigated the impact of transfusion on these parameters and assessed whether abnormal values prior to the transfusion became normal after transfusion (or conversely). RESULTS: There were 77 patients included in the study. Changes in mean values of mean corpuscular volume, soluble transferrin receptor, erythrocyte folate, cobalamin, haptoglobin, lactate dehydrogenase, C-reactive protein, and direct Coombs' test were not statistically significant. Changes in reticulocyte count, ferritin, transferrin saturation, serum folate, and total bilirubin concentrations were statistically significant, but they remained in the same diagnostic category (normal or abnormal) in 79% to 98% of the cases; 97% of patients with iron deficiency still had low ferritin or transferrin saturation after a transfusion. CONCLUSION: Blood tests performed after a one-time red blood cell transfusion can be used to establish the cause of anemia when they have not been performed before.

Reference change values of plasma and urine NGAL in cardiac surgery with cardiopulmonary bypass.

OBJECTIVE: As with any biomarker, interpretation of changes of NGAL concentration must consider its variability in a specific clinical setting. The aim of this study was to calculate the reference change value (RCV) and the index of individuality (II) of plasma and urine NGAL in the context of coronary artery bypass graft surgery with cardiopulmonary bypass, in patients without postoperative acute kidney injury. METHODS: This prospective single-center observational study included patients with a preoperative glomerular filtration rate of >30mlmin-1 1.73m-2, scheduled for elective coronary artery bypass graft with cardiopulmonary bypass and free from postoperative renal injury according to KDIGO criteria during hospital stay or a plasma creatinine Δ<0 (Δ=day1-induction). Plasma and urine NGAL were measured at anesthesia induction, 4h after intensive care admission and on the first and 2nd postoperative day and normalized to plasma proteins or urine creatinine. The RCV was given by the formula: 1.96×√2×√(CVa2+CVi2), were CVi is the intra-individual variability and CVa the reported analytical coefficient of variation of 5%. The II was calculated using the formula II=CVi/CVg for the four previous parameters, where CVg is the inter-individual variability. RESULTS: Of the 100 patients enrolled in the study, 73 or 25 were considered free from acute kidney injury (KDIGO and Δ creatinine criteria, respectively) and included in the analysis. The RCV was 104% and 109% for plasma NGAL and 321% and 608% for urine NGAL. The II was <0.6 for both plasma and urine NGAL. CONCLUSIONS: In patients who underwent coronary artery bypass grafting with normal post-operative kidney function, two-fold change in plasma NGAL and three to six-fold change in urine NGAL occur. In this specific clinical context, pathological variations must consider this biological "noise" for correct interpretation.

Determinants and prognostic value of Galectin-3 in patients with aortic valve stenosis.

OBJECTIVE: Myocardial fibrosis has been proposed as an outcome predictor in asymptomatic patients with severe aortic stenosis (AS) that may lead to consider prophylactic surgery. It can be detected using MRI but its widespread use is limited and development of substitute biomarkers is highly desirable. We analysed the determinants and prognostic value of galectin-3, one promising biomarker linked to myocardial fibrosis. METHODS: Patients with at least mild degenerative AS enrolled between 2006 and 2013 in two ongoing studies, COFRASA/GENERAC (COhorte Française de Rétrécissement Aortique du Sujet Agé/GENEtique du Rétrécissement Aortique), aiming at assessing the determinants of AS occurrence and progression, constituted our population. RESULTS: We prospectively enrolled 583 patients. The mean galectin-3 value was 14.3±5.6 ng/mL. There was no association between galectin-3 and functional status (p=0.55) or AS severity (p=0.58). Independent determinants of galectin-3 were age (p=0.0008), female gender (p=0.04), hypertension (p=0.002), diabetes (p=0.02), reduced left ventricular ejection fraction (p=0.01), diastolic dysfunction (E/e', p=0.02) and creatinine clearance (p<0.0001). Among 330 asymptomatic patients at baseline, galectin-3 was neither predictive of outcome in univariate analysis (p=0.73), nor after adjustment for age, gender, rhythm, creatinine clearance and AS severity (p=0.66). CONCLUSIONS: In a prospective cohort of patients with a wide range of AS severity, galectin-3 was not associated with AS severity or functional status. Main determinants of galectin-3 were age, hypertension and renal function. Galectin-3 did not provide prognostic information on the occurrence of AS-related events. Our results do not support the use of galectin-3 in the decision-making process of asymptomatic patients with AS. TRIAL REGISTRATION NUMBER: COFRASA NCT00338676 and GENERAC CT00647088.

Phaeohyphomycosis due to Alternaria infectoria: a single-center experience with utility of PCR for diagnosis and species identification.

The term phaeohyphomycosis refers to a rare group of fungal infections characterized by the presence of dark-walled hyphae or yeast-like cells in affected tissues. Herein, we report on the clinical and epidemiological characteristics of six cases of phaeohyphomycosis due to Alternaria spp. that occurred in our hospital over a 30-month period (from January 2008 to June 2010). Interestingly, whereas histopathological examinations were positive and fungal cultures yielded molds in all cases, mycological identification using conventional phenotypic methods was never possible despite prolonged incubation of the isolates. Identification of Alternaria infectoria species complex was obtained for each isolate by amplification and sequencing of the internal transcribed spacer of the ribosomal DNA (ITS rDNA). All patients had favourable outcomes following the introduction of azole-based antifungal therapy. This case series describes the clinical course of these six patients and highlights the utility of molecular identification to help in the identification of the etiologic agent when classical mycological methods have failed.