Carlo Mengoli

Use of PCR for diagnosis of invasive aspergillosis: Systematic review and meta-analysis

A systematic review and meta-analysis was done on the use of PCR tests for the diagnosis of invasive aspergillosis. Data from more than 10000 blood, serum, or plasma samples obtained from 1618 patients at risk for invasive aspergillosis were retrieved from 16 studies. Overall, the mean diagnostic odds ratios (DORs) of PCR for proven and probable cases were similar whether two consecutive positive samples were required to define positivity (DOR 15.97 [95% CI 6.83-37.34]) or a single positive PCR test was required (DOR 16.41 [95% CI 6.43-41.88]). Sensitivity and specificity of PCR for two consecutive positive samples were 0.75 (95% CI 0.54-0.88) and 0.87 (95% CI 0.78-0.93), respectively, and if only a single positive sample was required, these values were 0.88 (95% CI 0.75-0.94) and 0.75 (95% CI 0.63-0.84), respectively. Whereas specificity based on a single positive test was significantly lower (p=0.027) than two positive tests, the sensitivity and DOR did not differ significantly. A single PCR-negative result is thus sufficient to exclude a diagnosis of proven or probable invasive aspergillosis. However, two positive tests are required to confirm the diagnosis because the specificity is higher than that attained from a single positive test. Populations at risk varied and there was a lack of homogeneity of the PCR methods used. Efforts are underway to devise a standard for Aspergillus sp PCR for screening, which will help enable formal validation of PCR and estimate its use in patients most likely to benefit.

Aspergillus PCR: one step closer to standardization.

ABSTRACT PCR has been used as an aid in the diagnosis of invasive aspergillosis for almost 2 decades. A lack of standardization has limited both its acceptance as a diagnostic tool and multicenter clinical evaluations, preventing its inclusion in disease-defining criteria. In 2006, the European Aspergillus PCR Initiative was formed. The aim of the initiative was to provide optimal standardized protocols for the widespread clinical evaluation of the Aspergillus PCR to determine its diagnostic role and allow inclusion in disease diagnosis criteria. Quality control panels were developed and circulated to centers for evaluation of the existing methodology before recommendations based on the initial results were proposed for further panels. The centers were anonymously classified as “compliant” or “noncompliant,” according to whether they had followed the proposed recommendations before the performance parameters were determined and meta-regression analysis was performed. Most PCR amplification systems provided similar detection thresholds, although positivity was a function of the fungal burden. When PCR amplification was combined with DNA extraction, 50% of the centers failed to achieve the same level of detection. Meta-regression analysis showed positive correlations between sensitivity and extraction protocols incorporating the proposed recommendations and the use of bead beating, white cell lysis buffer, and an internal control PCR. The use of elution volumes above 100 μl showed a negative correlation with sensitivity. The efficiency of the Aspergillus PCR is limited by the extraction procedure and not by PCR amplification. For PCR testing of whole blood, it is essential that large blood volumes (≥3 ml) be efficiently lysed before bead beating to disrupt the fungal cell and performance of an internal control PCR to exclude false negativity. DNA should be eluted in volumes of <100 μl.

β-Glucan antigenemia assay for the diagnosis of invasive fungal infections in patients with hematological malignancies: a systematic review and meta-analysis of cohort studies from the Third European Conference on Infections in Leukemia (ECIL-3).

BACKGROUND Invasive fungal infections (IFIs) are life-threatening complications in patients with hemato-oncological malignancies, and early diagnosis is crucial for outcome. The compound 1,3-β-D-glucan (BG), a cell wall component of most fungal species, can be detected in blood during IFI. Four commercial BG antigenemia assays are available (Fungitell, Fungitec-G, Wako, and Maruha). This meta-analysis from the Third European Conference on Infections in Leukemia (ECIL-3) assessed the performance of BG assays for the diagnosis of IFI in hemato-oncological patients. METHODS Studies reporting the performance of BG antigenemia assays for the diagnosis of IFI (European Organization for Research and Treatment of Cancer and Mycoses Study Group criteria) in hemato-oncological patients were identified. The analysis was focused on high-quality cohort studies with exclusion of case-control studies. Meta-analysis was performed by conventional meta-analytical pooling and bivariate analysis. RESULTS Six cohort studies were included (1771 adult patients with 414 IFIs of which 215 were proven or probable). Similar performance was observed among the different BG assays. For the cutoff recommended by the manufacturer, the diagnostic performance of the BG assay in proven or probable IFI was better with 2 consecutive positive test results (diagnostic odds ratio for 2 consecutive vs one single positive results, 111.8 [95% confidence interval {CI}, 38.6-324.1] vs 16.3 [95% CI, 6.5-40.8], respectively; heterogeneity index for 2 consecutive vs one single positive results, 0% vs 72.6%, respectively). For 2 consecutive tests, sensitivity and specificity were 49.6% (95% CI, 34.0%-65.3%) and 98.9% (95% CI, 97.4%-99.5%), respectively. Estimated positive and negative predictive values for an IFI prevalence of 10% were 83.5% and 94.6%, respectively. CONCLUSIONS Different BG assays have similar accuracy for the diagnosis of IFI in hemato-oncological patients. Two consecutive positive antigenemia assays have very high specificity, positive predictive value, and negative predictive value. Because sensitivity is low, the test needs to be combined with clinical, radiological, and microbiological findings.

Meta-Analysis of BACTEC MGIT 960 and BACTEC 460 TB, with or without Solid Media, for Detection of Mycobacteria

ABSTRACT In a meta-analysis of 10 studies, the BACTEC 960/MGIT and BACTEC 460 systems showed a sensitivity and specificity in detecting mycobacteria (1,381 strains from 14,745 clinical specimens) of 81.5 and 99.6% and 85.8 and 99.9%, respectively. Combined with solid media, the sensitivity of the two systems increased to 87.7 and 89.7%, respectively.

Antifungal prophylaxis in liver transplant patients: A systematic review and meta-analysis†

We performed a meta‐analysis to determine whether antifungal prophylaxis decreases infectious morbidity and mortality in liver transplant patients. We searched for randomized trials dealing with prophylaxis with systemic antifungal agents. We used a fixed effect model, with risk ratio (RR) and 95% confidence interval (CI); we assessed study quality for heterogeneity and publication bias. Six studies (5 double‐blind), for a total of 698 patients, compared fluconazole, itraconazole, or liposomal amphotericin to placebo (5 studies) or oral nystatin. Prophylaxis reduced colonization (RR, 0.45; CI, 0.37‐0.55), total proven fungal infections (RR, 0.31; CI, 0.21‐0.46), which included both superficial (RR, 0.27; CI, 0.16‐0.45) and invasive (RR, 0.33; CI, 0.18‐0.59) infections, and mortality attributable to fungal infection (RR, 0.30; CI, 0.12‐0.75). Prophylaxis did not affect overall mortality (RR, 1.06; CI, 0.69‐1.64) or empiric treatment for suspected fungal infection (RR, 0.80; CI, 0.39‐1.67). The beneficial effect of antifungal prophylaxis was predominantly associated with the reduction of Candida albicans infection and mortality attributable to C. albicans. Compared to controls, however, patients receiving prophylaxis experienced a higher proportion of episodes of non–albicans Candida, and in particular of C. glabrata. No beneficial effect on invasive Aspergillus infection was observed. In conclusion, our analysis shows a clear, though limited, beneficial effect of antifungal prophylaxis in liver transplant patients. Concerns about the selection of triazole‐resistant Candida strains, however, are realistic, and the potential disadvantages of prophylaxis should be weighed against the established benefits. Liver Transpl 12:850–858, 2006.

Prophylaxis of Candida infections in adult trauma and surgical intensive care patients: a systematic review and meta-analysis

ObjectiveTo determine whether systemic antifungal prophylaxis decreases infectious morbidity and mortality in nonneutropenic, critically ill, trauma and surgical intensive care unit (ICU) adult patients.DesignSystematic review and meta-analysis of randomized clinical trials. We used a fixed effect model, with risk ratio (RR) and 95% confidence intervals (CI).ParticipantsPatients admitted to ICU after surgery or trauma, with multiple risk factors for fungal infections.InterventionsNine studies (seven double blind) with a total of 1,226 patients compared ketoconazole (three) or fluconazole (six) to placebo (eight) or no treatment (one).ResultsProphylaxis with azole was associated with reduced rates of candidemia (RR 0.30, 95% CI 0.10–0.82), mortality attributable to Candida infection (RR 0.25, 95% CI 0.08–0.80), and overall mortality (RR 0.60, 95% CI 0.45–0.81). Time to event analysis showed a significantly lower probability of fungal infections in treated patients. There was no evidence of statistical heterogeneity between studies, and publication bias assessment gave a negative results. There was, however, wide variability in the definition and reporting of some relevant clinical outcomes (e.g., confirmed or suspected infections, colonization) and pooling of these outcome measures was not feasible.ConclusionsProphylaxis of candidal infection among critically ill ICU patients has beneficial effect on certain outcome measures, but additional data from well designed clinical trials and long-term epidemiological observations are needed to provide firm recommendations for the selection of subgroups of patients who would most benefit from prophylaxis and to determine the effect of prophylaxis on fungal resistance patterns.

Abacavir use and cardiovascular disease events: a meta-analysis of published and unpublished data

Background:The use of abacavir (ABC) has been associated with an increased risk of cardiovascular disease in some cohort studies. However, no excess risk of myocardial infarction (MI) with ABC therapy has been observed in individual randomized clinical trials (RCTs) and in the aggregated clinical trials database maintained by the manufacturer of ABC. Objective:To combine all the evidence from RCTs by means of meta-analysis to estimate the effect of combined antiretroviral therapy (cART) containing ABC on MI and overall major cardiovascular events (CVEs). Methods:Primary outcomes included MI, CVE, adverse events requiring discontinuation of treatment, and overall mortality. We used a conventional Mantel–Haenszel method, with risk ratio and 95% confidence intervals (CIs) or, in the presence of heterogeneity, a random-effect model. Results:Data were from 28 primary RCTs (9233 participants) comparing ABC-containing cART (4376 participants) to other regimens not containing ABC (4857 controls). MI data were available from 18 trials (31 episodes in 7054 patients) and CVE data from 20 trials (79 episodes in 7899 patients). Compared to the controls, ABC use did not increase significantly the occurrence of MI (risk ratio 0.73, 95% CI 0.39–1.35; P = 0.31), CVE (risk ratio 0.95, 95% CI 0.62–1.44; P = 0.80), overall mortality (risk ratio 1.20, 95% CI 0.63–2.27; P = 0.58), and adverse events requiring discontinuation of treatment (risk ratio 0.82, 95% CI 0.67–1.00; P = 0.05). Conclusion:This meta-analysis of RCTs does not support the hypothesis that ABC-containing cART regimens carry a greater risk of MI or major cardiovascular events relative to comparator cART.

Evaluation of Aspergillus PCR Protocols for Testing Serum Specimens

ABSTRACT A panel of human serum samples spiked with various amounts of Aspergillus fumigatus genomic DNA was distributed to 23 centers within the European Aspergillus PCR Initiative to determine analytical performance of PCR. Information regarding specific methodological components and PCR performance was requested. The information provided was made anonymous, and meta-regression analysis was performed to determine any procedural factors that significantly altered PCR performance. Ninety-seven percent of protocols were able to detect a threshold of 10 genomes/ml on at least one occasion, with 83% of protocols reproducibly detecting this concentration. Sensitivity and specificity were 86.1% and 93.6%, respectively. Positive associations between sensitivity and the use of larger sample volumes, an internal control PCR, and PCR targeting the internal transcribed spacer (ITS) region were shown. Negative associations between sensitivity and the use of larger elution volumes (≥100 μl) and PCR targeting the mitochondrial genes were demonstrated. Most Aspergillus PCR protocols used to test serum generate satisfactory analytical performance. Testing serum requires less standardization, and the specific recommendations shown in this article will only improve performance.

Early Primary Cytomegalovirus Infection in Pregnancy: Maternal Hyperimmunoglobulin Therapy Improves Outcomes Among Infants at 1 Year of Age

BACKGROUND Primary cytomegalovirus (CMV) infection during pregnancy is the leading infectious cause of congenital neurological disabilities. Early CMV infection carries a higher risk of adverse neonatal outcome (sensorineural hearing loss or neurological deficits). Intravenous hyperimmunoglobulin (HIG) therapy seems to be promising, but its efficacy needs further investigation. METHODS Since 2002, we have enrolled consecutively all pregnant women with early (ie, before gestational week 17) CMV infection. Beginning in 2007, all women were offered treatment with HIG (200 UI per kilogram of maternal weight, in a single intravenous administration). Outcome of infants was evaluated at the age of 1 year. RESULTS Of the 592 women with early primary CMV infection, amniocentesis for CMV DNA detection was performed for 446. Of the 92 CMV-positive fetuses, pregnancy was terminated for 24, HIG was administered to mothers of 31, and no treatment was received by mothers of 37. Fetuses of treated mothers did not differ from fetuses of nontreated mothers according to mothers age, gestational week of infection, CMV load, or detection of abnormal ultrasonography findings. At the 1-year evaluation, 4 of 31 infants with treated mothers (13%; 95% confidence interval [CI], 1%-25%) and 16 of 37 infants with nontreated mothers (43%; 95% CI, 27%-59%) presented with poor outcomes (P < .01, by the 2-tailed Fisher exact test). CONCLUSIONS HIG treatment improved the outcome of fetuses from women who had primary CMV infection before gestational week 17.

Anal and oral human papillomavirus (HPV) infection in HIV-infected subjects in northern Italy: a longitudinal cohort study among men who have sex with men

BackgroundA study including 166 subjects was performed to investigate the frequency and persistence over a 6-month interval of concurrent oral and anal Human Papillomavirus (HPV) infections in Human Immunodeficiency Virus (HIV)-infected men who have sex with men (MSM).MethodsPatients with no previously documented HPV-related anogenital lesion/disease were recruited to participate in a longitudinal study. Polymerase chain reaction (PCR) was performed to detect HPV from oral and anal swabs and to detect Human Herpes Virus 8 (HHV-8) DNA in saliva on 2 separate specimen series, one collected at baseline and the other collected 6 months later. A multivariate logistic analysis was performed using anal HPV infection as the dependent variable versus a set of covariates: age, HIV plasma viral load, CD4+ count, hepatitis B virus (HBV) serology, hepatitis C virus (HCV) serology, syphilis serology and HHV-8 viral shedding. A stepwise elimination of covariates with a p-value > 0.1 was performed.ResultsThe overall prevalence of HPV did not vary significantly between the baseline and the follow-up, either in the oral (20.1 and 21.3%, respectively) or the anal specimens (88.6 and 86.3%). The prevalence of high-risk (HR) genotypes among the HPV-positive specimens was similar in the oral and anal infections (mean values 24.3% and 20.9%). Among 68 patients with either a HR, low-risk (LR) or undetermined genotype at baseline, 75% had persistent HPV and the persistence rates were 71.4% in HR infections and 76.7% in LR infections. There was a lack of genotype concordance between oral and anal HPV samples. The prevalence of HR HPV in anus appeared to be higher in the younger patients, peaking (> 25%) in the 43-50 years age group. A decrease of the high level of anal prevalence of all genotypes of HPV in the patients > 50 years was evident. HHV-8 oral shedding was positively related to HPV anal infection (p = 0.0046). A significant correlation was found between the persistence of HHV-8 shedding and HIV viral load by logistic bivariate analysis (Odds Ratio of HHV-8 persistence for 1-log increase of HIV viral load = 1.725 ± 0.397, p = 0.018).ConclusionsA high prevalence of HPV infection was found in our cohort of HIV-infected MSM, with a negative correlation between anal HPV infection and CD4 cell count.