Consecutive Positive Samples Research Articles

The Aspergillus galactomannan Ag VIRCLIA® Monotest and the sõna Aspergillus galactomannan lateral flow assay show comparable performance for the diagnosis of invasive aspergillosis.

Rapid galactomannan tests, such as the sõna Aspergillus GM Lateral Flow Assay (GM-LFA) and the Aspergillus Galactomannan Ag VIRCLIA® Monotest (GM-Monotest), which are suitable for the analysis of single samples, have the potential to accelerate diagnosis of invasive aspergillosis (IA). To compare the performance of the GM-Monotest and the GM-LFA for the diagnosis of IA. Two patient cohorts were analysed: adults who had received an allogeneic haematopoietic stem-cell transplant (alloHSCT-cohort) and patients with proven/probable IA from a 5-year period (cross-sectional IA-cohort). In the alloHSCT-cohort, weekly serum samples were tested, whereas in the cross-sectional IA-cohort sera and bronchoalveolar lavage fluids were analysed. The diagnostic performance was calculated using two definitions for positivity: (1) a single positive GM result and (2) at least two positive GM results from consecutive samples. IA classification followed EORTC/MSG 2019. The alloHSCT-cohort included 101 patients. Four had proven/probable IA, 26 possible IA and 71 no IA. The specificity for one positive serum and two consecutively positive sera was 88.7% and 100% (GM-Monotest) and 85.9% and 98.6% (GM-LFA). Comparison of ROC curves in the alloHSCT-cohort showed no significant difference. The cross-sectional IA-cohort included 59 patients with proven/probable IA. The sensitivity for one positive sample and two consecutively positive samples was 83.1% and 55.1% (GM-Monotest) and 86.4% and 71.4% (GM-LFA). Both assays showed comparable diagnostic performance with a higher sensitivity for the GM-LFA if two consecutive positive samples were required for positivity. However, due to poor reproducibility, positive GM-LFA results should always be confirmed.

Evaluation of the Dynamiker® Fungus (1-3)-β-D-Glucan Assay for the Diagnosis of Invasive Aspergillosis in High-Risk Patients with Hematologic Malignancies.

IntroductionThe Dynamiker® Fungus (1–3)-β-d-glucan assay (DFA) allows the testing of samples in smaller batches compared to the well-established Fungitell® assay (FA) making the assay cost-effective in centers with small numbers of samples. Evaluations of its performance for the diagnosis of invasive aspergillosis (IA) are limited. Therefore, we compared the two assays and evaluated their clinical performance in diagnosing IA.MethodsA total of 60 adult hematology patients were screened for IA, 13 with probable IA, 19 with possible IA, and 28 with no IA. Serum specimens (n = 166) were collected twice-weekly and tested for (1–3)-β-d-glucan (BDG) using FA and DFA which were compared quantitatively with Spearman rank correlation analysis and qualitatively with the Chi-square test. Agreement and error rates were determined using FA as the reference method. Sensitivity, specificity, and positive predictive and negative predictive values in diagnosing IA were calculated.ResultsThe performance of the DFA was highly consistent with that of the FA, both quantitatively (rs = 0.913) and qualitatively (kappa = 0.725). The agreement was 85% with 8% minor, no major, and 7% very major errors (FA+/DFA−). Using a cut-off value of 20 pg/mL for DFA, very major errors were reduced to 1%, although 5% major errors were detected. BDG levels were lower with DFA than FA (slope 0.653 ± 0.031). Sensitivity, specificity, positive predictive value, and negative predictive value (NPV) was 67%, 53%, 44%, and 74% for FA, and 53%, 67%, 49%, and 71% for DFA, respectively. The optimal BDG positivity threshold calculated did not lead to significant test quality improvement for either assay. However, a higher % of patients with probable IA (62%) had ≥ 2 consecutive positive specimens compared to patients with no IA (FA-BDG 26%, p = 0.10, and DFA-BDG 10%, p = 0.01) leading to improved sensitivity and NPV (71% and 85% for DFA, and 95% and 96% for FA, respectively).ConclusionDFA could be a valuable alternative to the FA, particularly in laboratories with small numbers of samples. The results of the BDG testing should be carefully interpreted in the high-risk setting of patients with hematologic malignancies. Higher NPV was found using as criterion ≥ 2 consecutive positive samples for diagnosing IA.

Pilot Study of Imatinib Discontinuation in Patients with Chronic Myeloid Leukemia with Deep Molecular Response (EDI-PIO) — Evaluation of Pioglitazone in Treatment-Free Remission

Introduction: Successful TKI discontinuation is feasible in approximately 40-60% of CML patients with stable and deep molecular response, but the persistence of quiescent CML stem cells (LSC) may be responsible for relapse. Pioglitazone, a PPARgamma agonist may reduce STAT5 activity and cause an erosion of CML LSC.Objectives: to evaluate safety and efficacy of pioglitazone in treatment-free remission (TFR) after imatinib discontinuation in patients with CML treated with pioglitazone for 3 months before imatinib discontinuation.Patients and methods: prospective, phase II trial. Inclusion criteria: CML in chronic phase, treated with imatinib for at least 3 years, with CCyR and stable deep molecular response (MR4.5) for at least 2 years. Patients received pioglitazone 30 mg/day, orally, for 3 months before imatinib discontinuation. BCR-ABL levels were measured by real-time quantitative PCR monthly for 12 months, every two months for 12 months, and then every 3 months during the subsequent follow-up. Imatinib was reinitiated at molecular relapse, defined as any single sample with a value of >0.1% (loss of major molecular response - MMR) or two consecutive positive samples with a value >0.01% (loss of MR4.0). Treatment-free remission (TFR) was calculated from imatinib discontinuation until molecular relapse, resumption of imatinib by any cause, progression to advanced phases or death to any cause.Results: Recruitment is ongoing. Between June 2016 and July 2017, 21 chronic phase CML patients were included. Median age was 48 years (23-65) at CML diagnosis and 56 years (29-76) at trial initiation; 52.4% male; Sokal: 62.5% low risk, 25% intermediate, 12.5% high risk; 14% treated previously with IFN. Two patients had diabetes and were using hypoglycemic drugs. The median time between diagnosis and imatinib start was 2 months (1-39); the median duration of imatinib treatment was 8.2 years (4-12). Nineteen patients received pioglitazone for 3 months and discontinued imatinib and two are still using both. There were no grade 2 or 3 adverse events related to pioglitazone; one patient did not complete the first month of pioglitazone treatment due to worsening of edema and went to discontinuation phase. The median follow-up of the 20 patients that discontinued imatinib was seven months (0-11). One patient dropped out of the trial and was censured in the analysis. Seven/18 patients (38%) presented newly or worsening musculoskeletal pain or arthralgia grades 1-2 occurring within 1-6 months after imatinib discontinuation. The two diabetic patients presented increase in glucose levels (grade 2 and 3), seven and eight months after imatinib discontinuation. There was no loss of hematological response or transformation to advanced phases. However, 4/18 (22%) patients (all male) reinitiated imatinib after molecular relapse: 1 lost MMR and CCyR response; 2 lost MMR, one had confirmed loss of MR4. Two of them recovered RM4.0 in 2 and 3 months after imatinib reintroduction. TFR was 74% (95% CI: 52-96%) in 9 months. TFR was higher in female patients (100% vs. 45%, P=0.019).Conclusion: Pioglitazone was well tolerated in the majority of the patients. The rate of withdraw syndrome was similar to the reported in other discontinuation trials. Increase in glucose levels was observed in two patients with diabetes after imatinib discontinuation. TFR was higher in female patients. A longer follow-up is necessary to evaluate the duration of TFR.This trial is registered in ClinicalTrials.gov (NCT02852486) DisclosuresPagnano:Bristol-Meirs Squibb: Consultancy, Speakers Bureau; Roche: Speakers Bureau; Amgen: Consultancy; Novartis: Consultancy.

MO875SEROCONVERSION RATE AND PERSISTANCE OF IGG RESPONSE TO SARS-COV2 IN HEMODIALYSIS PATIENTS. A CASE SERIES STUDY

Background and AimsHigher incidence and worse outcome of coronavirus disease (COVID-19) are observed in dialysis patients, mainly due to weak immune response. However, little is known about seroconversion ability and duration of antibody response after COVID-19 in this group. The aim of this study was to estimate the seroconversion rate and the persistence of IgG response to SARS-CoV2 in dialysis patients.MethodFour (4) dialysis patients previously infected with SARS-CoV2 were included in this study. Initially, all patients were tested for the presence of IgG antibodies 21-35 days after the onset of their symptoms. The cut-off value for positivity was a ratio of ≥ 1.4. Those patients with at least two consecutive positive samples were defined as seropositives. Seropositives were then having their antibodies tested monthly for a maximum period of six months or until the first negative result. Duration of antibody persistence was defined as the time between the day IgG were last detected and the day of onset of infection.ResultsAll four patients were seropositives after the initial test (seroconversion rate = 100%) with a mean IgG ratio of 6.44 (±1.28). Median follow up period was 128 (range 96-193) days. Median duration of antibody persistence was 153 (range 103-193) days. By the sixth month, IgG had turned negative in two of four patients (rate = 50%).ConclusionIn our study, dialysis patients showed a remarkable seroconversion rate after infection with SARS-CoV2. However, a rapid decline of IgG antibodies was observed in half of them.

Persistence of IgG response to SARS-CoV-2

Persistence of IgG response to SARS-CoV-2

Quantitative real-time PCR detection of adenovirus in clinical blood specimens: A comparison of plasma, whole blood and peripheral blood mononuclear cells

Background Detection and quantification of adenovirus (ADV) in peripheral blood specimens has become an increasingly important tool in the management of immunosuppressed patients. Investigators have described the use of whole blood (WB), peripheral blood mononuclear cells (PBMC), serum and plasma but no studies have compared the utility of these different sample types for use in a clinical diagnostic assay. Objectives To determine the optimal blood compartment for quantitative real-time measurement of adenovirus in peripheral blood specimens. Study design WB, PBMC, and plasma representing 338 samples from 148 patients were tested for ADV by quantitative real-time PCR (qrt-PCR) and the results compared for concordance of both qualitative sensitivity and viral load among positive specimens. Results There was no significant difference in qualitative sensitivity among the three tested specimen types. Quantitative values of WB and plasma were similar and tended to be greater than those found in PBMC samples. Comparison of consecutive positive samples within individual patients showed that viral loads tracked similarly over time, irrespective of the sample type tested. Conclusion While WB and plasma do not offer a significant increase in sensitivity over PBMC, they may offer benefits in terms of reduced processing costs and laboratory turn around time.

Polymerase chain reaction screening for fungemia and/or invasive fungal infections in patients with hematologic malignancies

Invasive fungal infections (IFIs) are a life-threatening complication in patients with hematologic malignancies, mainly in acute leukemia patients, following chemotherapy. IFI incidence is increasing, and associated mortality remains high due to unreliable diagnosis. Antifungal drugs are often limited by inadequate antimicrobial spectrum and side effects. Thus, the detection of circulating fungal DNA has been advocated as a rapid, more sensitive diagnostic tool. Between June 01 and January 03, weekly blood samples (1,311) were screened from 193 patients undergoing intensive myelosuppressive or immunosuppressive therapy. IFI cases were classified according to European Organization for Research and Treatment of Cancer/Mycoses Study Group criteria. Fungal DNA was extracted from whole blood and amplified using polymerase chain reaction (PCR) published primers that bind to the conserved regions of the fungal 18S rRNA gene sequence. In our study, two or more consecutive positive samples were always associated with fungal disease. PCR screening predicted the development of IFI to be 17 days (median). This test had a specificity of 91.1% and a sensitivity of 75%. IFI incidence was 7.8%. Therefore, our results confirm the potential usefulness of PCR serial screening and the clinical applicability in everyday routine. PCR screening offers a noninvasive repeatable aid to the diagnosis of IFI.

Appearance and disappearance of neutralizing antibodies during interferon-beta therapy

Neutralizing antibodies (NABs) occur frequently in patients receiving interferon (IFN)-beta for multiple sclerosis (MS), but it is unclear whether occurrence of NABs is predictive for the persistence of NABs during continued IFN-beta therapy. The authors used an antiviral neutralization bioassay to measure NABs blindly from 6 months up to 78 months in patients with MS who were followed for at least 24 months during treatment with IFN-beta. Patients were classified into three groups: 1) persistently NAB-negative patients, defined as patients without any positive samples at any time; 2) definitely NAB-positive patients, defined as patients who had at least two consecutive positive samples; and 3) patients with fluctuating NAB-positive and NAB-negative samples. A total of 455 patients were included in the study. Overall, 52.3% of the patients were persistently NAB-negative, 40.9% became definitely NAB-positive, and the remaining 6.8% were fluctuating. More patients treated with IFN-beta-1a (Avonex) remained NAB-negative (p < 0.0001), whereas there was no difference between IFN-beta-1b (Betaferon) and IFN-beta-1a (Rebif). Patients who have remained NAB-negative during the first 24 months of therapy rarely developed NABs. On the contrary, the majority of patients, who had been NAB-positive from 12 through 30 months after start of therapy, remained NAB-positive. NABs should be measured in all patients treated with IFN-beta. If patients have been persistently NAB-negative for 24 months, measurements can be discontinued. Patients who have been NAB-positive for a period of 18 months or more usually remain NAB-positive for a long time.

Neutralizing antibodies reduce the efficacy of βIFN during treatment of multiple sclerosis

To analyze the impact of neutralizing antibodies (NAbs) on the clinical efficacy of IFNbeta. This was an open-label study involving 78 patients with multiple sclerosis treated with Betaferon 8 million IU (MIU) subcutaneously (SC) every other day (n = 20), Rebif 22 micro g SC 3 times weekly (n = 25), or Avonex 30 micro g IM once weekly (n = 33). Every 3 months, blood samples were collected and sera were analyzed for NAbs using an antiviral cytopathic effect assay. Patients were categorized according to their NAb status: NAb negative (NAb-); isolated NAb positive (NAb+), patients with > or =1 positive sample (titer > or = 20); and persistent NAb+, patients with > or =2 consecutive positive samples (titer > or = 20). Patients who were NAb- and persistent NAb+ were compared for relapse rate, time between first and second relapse, percentage of relapse-free patients, and percentage of patients who had a sustained progression of > or =1 point on the Expanded Disability Status Scale (EDSS). The incidence of persistent NAb+ patients was 35% for Betaferon, 20% for Rebif, and 3% for Avonex. During IFNbeta treatment, both NAb+ and NAb- patients showed a reduction in relapse rate; this reduction (25%) was not significant in NAb+ patients but was significant (67%; p < 0.0001) in NAb- patients. In addition, the mean relapse rate was higher (p = 0.039), mean time between first and second relapse was shorter (13 vs 21 months; p = 0.0064), and there was a trend suggesting that NAbs affected the probability of remaining relapse free (p = 0.08). A higher percentage of NAb+ patients versus NAb- patients had worsening of EDSS scores during follow-up (p = 0.013). Persistent NAbs significantly reduce the clinical efficacy of IFNbeta.

Differential effects of three interferon betas on neutralising antibodies in patients with multiple sclerosis: a follow up study in an independent laboratory

Objective: To evaluate the incidence and the prevalence of neutralising antibodies (NABs) to three interferon beta (IFNβ) products in patients with multiple sclerosis (MS). Methods: Sera were tested from 125...

Monthly corticosteroids decrease neutralizing antibodies to IFNβ1b: a randomized trial in multiple sclerosis

Neutralizing antibodies (NAB) to interferon beta (IFNbeta) occur in some multiple sclerosis (MS) patients, particularly during the first year of treatment. The presence of NAB may be associated with an attenuation of the therapeutic effect. The aim of this study was to compare the frequency of NAB occurrence in patients treated with IFNbeta-1 b with that in patients treated with IFNbeta-1 b combined with monthly pulses of intravenous methylprednisolone (MP). One hundred and sixty-one patients with relapsing-remitting MS were randomized in two treatment arms: 8 MIU of IFNbeta- 1 b subcutaneously injected every other day either alone or in combination with 1000 mg of monthly intravenous MP. NAB were evaluated at baseline and at months 3,6,9,12 and 15 by the MxA assay in a specialized laboratory. Positivity was defined as a titer of > or = 20 neutralizing units according to two different definitions: I) one or more non-consecutive positive samples, II) at least two consecutive positive samples. NAB (definition I) were observed in 26.8% of patients in the IFNbeta-1 b alone arm and in 12.1% of patients in the combination therapy arm (p = 0.05 by the chi-square test), which corresponds to a relative reduction of 54.9%, whereas according to definition II, these figures dropped to 22.5 % for the IFNbeta-1 b alone arm, and 10.6% for the combination therapy arm (relative reduction 52.9%, p = 0.10, NS). A higher probability of remaining in the NAB-free status was observed in patients treated with the combination therapy (p = 0.031 for definition I and p = 0.o49 for definition II, by the Wilcoxon-Gehan test). Methylprednisilone combined with IFNbeta-1 b reduces the incidence of neutralizing bodies to in terferon-beta during the first year of treatment in MS patients.

Rotavirus infection and diarrhea in healthy and HIV-infected children: a cohort study.

Rotavirus infection and diarrhea in healthy and HIV-infected children: a cohort study.

Early detection of human cytomegalovirus viremia in bone marrow transplant recipients by DNA amplification

Surveillance blood cultures for human cytomegalovirus (HCMV) are commonly used to identify the bone marrow transplant (BMT) recipients with the highest risk of serious HCMV disease and for whom early interventional ganciclovir therapy would be beneficial. We monitored 36 allogeneic BMT recipients weekly for the presence of HCMV in the blood from 0 to 100 days posttransplantation. Viable HCMV in leukocytes (WBC) was detected by shell vial and tube culture methods. HCMV DNA in WBC and plasma was detected by PCR and DNA hybridization using primers and a probe from the EcoRI fragment D region of HCMV AD169. A uracil-N-glycosylase-dUTP PCR protocol was used to prevent false-positive results due to amplicon carryover. Seventeen patients had multiple consecutive positive samples containing HCMV DNA in plasma or WBC. In 14 of 17 patients, HCMV was also detected by blood culture. HCMV DNA was detected sporadically in six patients, none of whom had positive cultures. One patient had HCMV viremia detected by WBC culture only. The remaining 12 patients had no positive PCR assays or blood cultures. For the patients with positive blood cultures, PCR detection of HCMV DNA in plasma preceded detection of HCMV in culture by a mean of 8 days and detection in WBC preceded detection in culture by 6 days. HCMV disease (interstitial pneumonia) was documented for two patients with viremia (blood culture and PCR positive) and one patient without viremia (blood culture and PCR negative). The earlier recognition of high-risk patients provided by detection of HCMV DNA in plasma or WBC may improve the efficacy of early interventional antiviral therapy.

The presence of cervical and vaginal fetal fibronectin predicts preterm delivery in an inner-city obstetric population

It has previously been shown that fibronectin bearing a specific oncofetal domain is present at the chorionic-decidual interface and that its release into cervical and vaginal secretions accurately predicts preterm delivery in patients with uterine contractions. This study examines whether serial assessment of cervical and vaginal fetal fibronectin allows for the prediction of preterm delivery in symptom-free patients derived from an inner-city, general obstetric population. Cervical and vaginal samples were obtained from 429 consenting patients who received routine prenatal care between 24 and 37 weeks' gestation. A sensitive immunoassay was used to quantitate cervical and vaginal fetal fibronectin levels, and clinicians were blinded to fetal fibronectin results. Post hoc receiver operating characteristic curve analysis was used to determine which sample site (cervical or vaginal), fetal fibronectin concentration, and number of consecutive positive samples optimized screening efficacy. Logistic regression was employed to determine whether fetal fibronectin was an independent predictor of preterm delivery. The spontaneous preterm delivery rate was 11% (49/429). Among the 326 patients sampled within 28 days of delivery, receiver operating characteristic curve analysis indicated that the presence of a single cervical fetal fibronectin value > 60 ng/ml between 24 and 36 weeks' gestation predicted preterm delivery with a sensitivity of 73%, a specificity of 72%, and positive and negative predictive values of 25% and 95%, respectively. A vaginal fetal fibronectin value > 50 ng/ml predicted preterm delivery with a sensitivity of 68%, a specificity of 80%, and positive and negative predictive values of 30% and 95%, respectively. Cervical and vaginal fetal fibronectin predicted preterm deliveries resulting from both membrane rupture and preterm labor with intact membranes. A positive fetal fibronectin result preceded preterm delivery by 3.4 (+/- 3.2) weeks. Stepwise logistic regression demonstrated that cervical and vaginal fetal fibronectin levels were independent predictors of preterm delivery with adjusted odds ratios of 8.9 (95% confidence interval 3.6 to 22.1) and 6.0 (95% confidence interval 2.6 to 13.7), respectively. Among patients undergoing monthly cervical and vaginal sampling between 24 and 36 weeks' gestation, the presence of fetal fibronectin is a sensitive and specific predictor of preterm delivery.

Dépistage des infections urinaires asymptomatique chez l'enfant et l'adolescent. Principe et méthode

Screening for asymptomatic urinary infections in children and adolescents. Principles and method The reasons for early detection of inapparent urinary infections in young girls are discussed. The technical methods of gaining midstream urine and of preparation of urinary cultures by the “Uricult” technique are described. Two consecutive positive samples from the same person, revealing the same germs, indicate the need for further urological evaluation and for appropriate treatment. Its effectiveness is evaluated by repeatet bacteriological follow-up examinations.