Plasma DNA Levels Research Articles

Prospective Analysis of Human Cytomegalovirus DNAemia and Specific CD8+ T Cell Responses in Lung Transplant Recipients

In lung transplant recipients (LuTRs), human cytomegalovirus (HCMV) DNAemia may be associated with HCMV disease and reduced survival of the allograft. Because T cells are essential for controlling HCMV replication, we investigated in this prospective study whether the kinetics of plasma HCMV DNA loads in LuTRs are associated with HCMV-specific CD8+ T cell responses, which were longitudinally assessed using a standardized assay. Sixty-seven LuTRs were monitored during the first year posttransplantation, with a mean of 17 HCMV DNA PCR quantifications and 11.5 CD8+ T cell tests performed per patient. HCMV-specific CD8+ T cell responses displayed variable kinetics in different patients, differed significantly before the onset of HCMV DNAemia in LuTRs who subsequently experienced episodes of DNAemia with high (>1000 copies/mL) and low plasma DNA levels (p = 0.0046, Fisher's exact test), and were absent before HCMV disease. In HCMV-seropositive LuTRs, high-level DNAemia requiring preemptive therapy occurred more frequently when HCMV-specific CD8+ T cell responses fluctuated, were detected only after HCMV DNA detection, or remained undetectable (p = 0.0392, Fisher's exact test). Thus, our data indicate that HCMV-specific CD8+ T cells influence the magnitude of HCMV DNAemia episodes, and we propose that a standardized measurement of CD8+ T cell immunity might contribute to monitoring the immune status of LuTRs posttransplantation.

Plasma nuclear and mitochondrial DNA levels as predictors of outcome in severe sepsis patients in the emergency room.

Background and aimThe sensitivity and specificity of biomarkers and scoring systems used for predicting fatality of severe sepsis patients remain unsatisfactory. This study aimed to determine the prognostic value of circulating plasma DNA levels in severe septic patients presenting at the Emergency Department (ED).MethodsSixty-seven consecutive patients with severe sepsis and 33 controls were evaluated. Plasma DNA levels were estimated by real-time quantitative polymerase chain reaction assay using primers for the human β-hemoglobin and ND2 gene. The patients’ clinical and laboratory data on admission were analyzed.ResultsThe median plasma nuclear and mitochondria DNA levels for severe septic patients on admission were significantly higher than those of the controls. The mean plasma nuclear DNA level on admission correlated with lactate concentration (γ = 0.36, p = 0.003) and plasma mitochondrial DNA on admission (γ = 0.708, p < 0.001). Significant prognostic factors for fatality included mechanical ventilation within the first 24 hours (p = 0.013), mean sequential organ failure assessment (SOFA) score on admission (p = 0.04), serum lactate (p < 0.001), and both plasma nuclear and mitochondrial DNA on admission (p < 0.001). Plasma mitochondrial DNA was an independent predictor of fatality by stepwise logistic regression such that an increase by one ng/mL in level would increase fatality rate by 0.7%.ConclusionPlasma DNA has potential use for predicting outcome in septic patients arriving at the emergency room. Plasma mitochondrial DNA level on admission is a more powerful predictor than lactate concentration or SOFA scores on admission.

A multifactorial relationship exists between total circulating cell‐free DNA levels and maternal BMI

A multifactorial relationship exists between total circulating cell‐free DNA levels and maternal BMI

A Phase II Trial of Erlotinib as Maintenance Treatment After Gemcitabine Plus Platinum-based Chemotherapy in Patients With Recurrent and/or Metastatic Nasopharyngeal Carcinoma

Despite the efficacy of gemcitabine-platinum regimen, the outcome of patients with recurrent and/or metastatic nasopharyngeal carcinoma (RM NPC) is poor. A phase II trial was conducted to determine the efficacy of erlotinib, given as maintenance therapy after gemcitabine-platinum chemotherapy in patients with RM NPC. Patients were treated with gemcitabine 1000 mg/m on days 1 and 8 as well as cisplatin 70 mg/m on day 1 (or carboplatin area under curve 5 on day 1, if contraindication to cisplatin) 3 weeks. After 6 chemotherapy cycles (or before in case of progression), patients were switched to erlotinib 150 mg/d 4 weeks. Primary end point was time to progression in patients without progressive disease after 6 chemotherapy cycles and treated with maintenance erlotinib. Epstein-Barr virus DNA plasma levels, measured using quantitative real-time polymerase chain reaction, were correlated with outcome. Of 20 enrolled patients, 19 patients received 96 chemotherapy cycles. Fifteen patients were switched to erlotinib and received 36 cycles (range: 1 to 6 cycles). Safety profiles observed with the chemotherapy combination and erlotinib were those expected. Of 12 patients evaluable for response to erlotinib, all progressed except 3 patients (25%) who had stable disease for 3, 4, and 7 months, respectively. Median time to progression was 6.9 months for 13 patients without progressive disease after 6 chemotherapy cycles and treated with erlotinib. No correlation was identified between Epstein-Barr virus DNA plasma levels and clinical outcome. Maintenance or second-line therapy with erlotinib after chemotherapy was not effective in RM NPC. Historical comparison with patients treated with the same chemotherapy alone until progression suggests that it may be detrimental to stop chemotherapy after 6 cycles if disease did not progress.

Plasma DNA and DNA integrity in breast cancer patients undergoing neoadjuvant chemotherapy.

e21067 Background: In breast cancer patients undergoing neoadjuvant chemotherapy before surgery, biomarkers for predicting the response to the therapy are highly needed. Methods: Concentrations of ALU115, ALU247 and DNA integrity were analyzed in prospectively collected plasma of 68 patients with localized breast cancer (UICC II and III), of 47 patients with metastatic breast cancer and 28 healthy women as controls. In all 68 patients with breast cancer who had completed the course of chemotherapy until surgery, DNA and tumor biomarkers CEA and CA 15-3 were evaluated concerning response to therapy (no change, NC: N=18; partial remission, PR: N=35; complete remission, CR: 15). Results: Plasma levels of ALU 115 and ALU 247 were significantly higher in patients with localized (medians 16.3 and 16.8 ng/mL) and metastasized breast cancer (22.2 and 29.8 ng/mL) than in healthy controls (1.8 and 1.9 ng/mL). However, plasma DNA integrity showed no significant differences between the diagnostic groups. AUCs in ROC curves for discrimination of localized breast cancer from healthy controls were 96% for ALU 115 and ALU 247, respectively, and 60% for DNA integrity. Concerning therapy response, pretherapeutic ALU 115, 247, and DNA integrity and also CEA and CA 15-3 were not significantly different when patients with and without remission (CR vs PR+NC and CR+PR vs NC) were compared. Conclusions: While plasma DNA levels are valuable for discrimination of breast cancer patients from controls, pretherapeutic DNA integrity provides no additive diagnostic information nor indicates response to neoadjuvant therapy.

Quantitative analysis of free-circulating DNA in plasma of patients with resectable NSCLC

Objective: Minute amounts of free-circulating DNA are present in plasma of healthy individuals, whereas its increased concentration was observed in patients with malignant tumors including non-small cell lung cancer (NSCLC). This study aimed at demonstrating the potential usefulness of plasma DNA concentration monitoring in NSCLC patients for therapy effectiveness assessment throughout the treatment and follow-up period.Methods: Plasma DNA concentration was assessed in 50 NSCLC patients (stage I – IIIA) prior and following the radical treatment using real-time quantitative PCR method. 10 orthopedic patient undergoing hip joint surgery and 40 healthy volunteers comprised control groups.Results: NSCLC patients (8.02 ng/ml) demonstrated significantly higher mean plasma DNA concentration with respect to healthy controls (2.27 ng/ml; p < 0.0000). Drastic increase in plasma DNA levels up to mean 68.74 ng/ml was detected a week after primary tumor resection. Still, similar phenomenon was observed in patients subjected to orthopedic surgical treatment (from 3.00 to 28.38 ng/ml, p < 0.0015). Most resected NSCLC patients with no disease recurrence during 3- to 6-month follow-up demonstrated reduced plasma DNA levels (mean 2.77 ng/ml) with respect to their presurgical values, whereas in relapsed subjects plasma DNA levels were significant higher.Conclusion:Free-circulating DNA concentration in plasma was significantly higher in NSCLC patients versus healthy controls. Its drastic increase following radical NSCLC treatment was most likely due to the surgical trauma. Importantly, the kinetics of plasma free-circulating DNA seems to be a promising marker of long-term effects of radical surgery in NSCLC.

Clinical Significance of Low Cytomegalovirus DNA Levels in Human Plasma

The clinical significance of the detection of low copy numbers of cytomegalovirus (CMV) DNA in immune-suppressed patients remains unclear. In this study, we compared the artus CMV Rotor-Gene PCR, utilizing an automated nucleic acid extraction and assay setup (the artus CMV protocol), with the COBAS Amplicor CMV Monitor test (our reference protocol). We then analyzed the results of all CMV PCR tests ordered following the implementation of the artus CMV protocol at our institution and followed 91 adult patients with positive test results. The artus CMV protocol had a linear range extending from 2.0 to 7.0 log(10) copies/ml and had a lower limit of 95% detection of 57 copies/ml. With archived plasma samples, this protocol demonstrated 100% sensitivity and 94% specificity for the detection of CMV DNA. Following implementation of the artus CMV protocol, 320 of 1,403 (22.8%) plasma samples tested positive (compared with 323/3,579 [9.0%] samples in the preceding 6 months), and 227 (16.2%) samples had copy numbers of <400/ml. Ninety-one adult patients had at least one positive test. The data were analyzed using a threshold of 200 copies/ml, and in 22 episodes, the viral load increased from <200 copies/ml to ≥ 200 copies/ml on sequential tests. In 21 of these 22 episodes, either the viral load continued to increase or antiviral treatment was initiated in response to the repeat value. In summary, we evaluate the performance characteristics of a protocol utilizing the artus CMV PCR and identify clinically meaningful changes in CMV DNA copy numbers even when they are initially detected at a low level.

Can plasma DNA monitoring be employed in personalized chemotherapy for patients with advanced lung cancer?

Personalized chemotherapy is the ideal treatment usually chosen to help improve the survival chances of patients with advanced lung cancer. However, there is no short-term evaluation protocol for predicting the efficacy of the therapy. The aim of this study was to determine the value of using plasma DNA to monitor chemotherapeutic efficacy and to select most appropriate chemotherapeutic regimen for patients with advanced lung cancer. Eighty-eight lung cancer patients and 200 healthy controls were included in this study. Plasma DNA was extracted from plasma samples with internal controls by using the BILATEST DNA Kit. The quantity of plasma DNA was determined by using duplex real-time quantitative PCR. After first-line chemotherapy, plasma DNA levels of partial response patients were significantly different from those of stable disease patients or progressive disease patients, but with no statistical difference from healthy controls (P=0.014, P<0.001 and P=0.418, respectively). Survival analysis showed a statistically better survival time in patients who had lower levels of plasma DNA after the third cycle chemotherapy (P=0.031). In this study, the correlation of the kinetics of DNA concentrations with chemotherapeutic efficacy during the whole therapy was also observed. The quantification of plasma DNA is a sensitive indicator of chemotherapeutic efficacy in advanced lung cancer patients, and it can be useful in predicting response to therapy and guiding medication.

Associations between Virologic and Immunologic Dynamics in Blood and in the Male Genital Tract

To determine the influence of asymptomatic genital viral infections on the cellular components of semen and blood, we evaluated the associations between the numbers and activation statuses of CD4+ and CD8+ T lymphocytes in both compartments and the seminal levels of cytomegalovirus (CMV), herpes simplex virus (HSV), and human immunodeficiency virus 1 (HIV). Paired blood and semen samples were collected from 36 HIV-infected antiretroviral-naïve individuals and from 40 HIV-uninfected participants. We performed multiparameter flow cytometry analysis (CD45, CD45RA, CD3, CD4, CD8, and CD38) of seminal and blood cellular components and measured HIV RNA and CMV and HSV DNA levels in seminal and blood plasma by real-time PCR. Compared to HIV-uninfected participants, in the seminal compartment HIV-infected participants had higher levels of CMV (P < 0.05), higher numbers of total CD3+ (P < 0.01) and CD8+ subset (P < 0.01) T lymphocytes, and higher CD4+ and CD8+ T lymphocyte activation (RA-CD38+) (P < 0.01). Seminal CMV levels positively correlated with absolute numbers of CD4+ and CD8+ T cells in semen (P < 0.05) and with the activation status of CD4+ T cells in semen and in blood (P < 0.01). HIV levels in semen (P < 0.05) and blood (P < 0.01) were positively associated with T-cell activation in blood. Activation of CD8+ T cells in blood remained an independent predictor of HIV levels in semen in multivariate analysis. The virologic milieu in the male genital tract strongly influences the recruitment and activation of immune cells in semen and may also modulate T-cell immune activation in blood. These factors likely influence replication dynamics, sexual transmission risk, and disease outcomes for all three viruses.

Quantitation of Plasma Circulating DNA Using Quantitative PCR for the Detection of Hepatocellular Carcinoma

Circulating DNA is a potential biomarker for tumor diagnosis and prognosis. This study was aimed to quantify the circulating DNA in plasma from patients with hepatocellular carcinoma (HCC) using quantitative PCR and evaluate its potential clinical value. Blood samples were collected from 72 patients with HCC, 37 with liver cirrhosis or chronic hepatitis and 41 healthy volunteers. Plasma DNA was extracted and quantified by a real-time quantitative PCR method. The diagnostic and prognostic value of plasma DNA analysis for HCC was evaluated. DNA levels in the HCC plasma (median: 173ng/mL) were significantly higher than those in the healthy controls (9ng/mL) or control benign patients (46ng/mL) (P < 0.001). The area under the receiver-operation characteristic (ROC) curve (AUC) assessing plasma DNA was 0.949 for healthy controls and 0.874 for control patients. Plasma DNA detection could discriminate HCC from normal controls with 90.2% sensitivity and 90.3% specificity at the cut-off value of 18.2ng/mL. Combined ROC analyses using plasma DNA and serum AFP revealed an elevated AUC of 0.974 with 95.1% sensitivity and 94.4% specificity in discriminating HCC from normal controls. The plasma DNA levels were positively associated with tumor size (P = 0.012), and were significantly elevated in HCC patients with intrahepatic spreading or vascular invasion (P = 0.035). The overall survival time of patients with high plasma DNA levels showed a shortened tread when compared with that of patients with low plasma DNA concentrations (P = 0.071). Plasma DNA may be a valuable noninvasive tool for the detecting and predicting the metastasis potential of HCC; and the prognostic value of plasma DNA needed further investigation.

Study of quantitative detection of circulating DNA in the plasma of patients with cervical lesion

To quantitatively detect circulating DNA levels in the plasma of patients withcervical lesion and to determine the value for diagnosis of cervical lesion and cervical cancer. Preoperative blood samples were collected from 53 cases of low-grade lesions, 49 cases of high-grade lesions, 44 cases of cervical invasive cancer and 70 cases of healthy women. Plasma DNA was extracted by magnetic bead method (BILATEST DNA kit). The quantity of plasma DNA was determined by duplex real-time quantitative PCR. Median plasma DNA level of invasive cervical cancer patients was 61.59 mg/L (32.06-162.16 mg/L), which was significantly higher than that of healthy women [16.35 mg/L (11.98-22.71 mg/L), P<0.01]. Among invasive cervical cancer patients, median plasma DNA level of squamous carcinoma patients was slightly higher than that of adenocarcinoma (50.43 versus 47.31 mg/L, P>0.05). Median plasma DNA level of stage I patients was lower than that of stage II-III patients (46.02 versus 71.35 mg/L, P<0.05). Quantitatively detecting plasma circulating DNA may be with some application prospect in the diagnosis of cervical diseases.

Predictive power of hepatitis B 1762T/1764A mutations in plasma for hepatocellular carcinoma risk in Qidong, China

Hepatocellular carcinoma (HCC) is a leading cause of cancer mortality with nearly 700,000 deaths occurring annually. Hepatitis B virus (HBV) is a major contributor to HCC and acquired mutations in the HBV genome may accelerate its pathogenesis. In this study, a matched case-control investigation of 345 men who died of HCC and 625 controls were nested within a cohort of male hepatitis B surface antigen (HBsAg) carriers from Qidong, China. Matched preserving odds ratios (ORs) were used as a measure of association and 95% confidence intervals (CIs) as a measure of precision. Real-time polymerase chain reaction allowed for a quantitative comparison of the levels of the HBV 1762(T)/1764(A) mutation in cases and controls. A total of 278 (81%) of the cases were positive for the HBV 1762(T)/1764(A) mutation compared with 250 (40%) of the controls. The matched preserving OR of 6.72 (95% CI: 4.66 to 9.68) strongly indicated that cases were significantly more probably than controls to have the mutation. Plasma levels of DNA harboring the HBV mutation were on average 15-fold higher in cases compared with controls (P < 0.001). Most strikingly, the level of the mutation in the 20 controls who later developed and died of HCC were on average 274-fold higher than controls who did not develop HCC. Thus, within this cohort of HBsAg carriers at high risk of developing HCC, individuals positive for the HBV 1762(T)/1764(A) mutation at enrollment were substantially more probably to subsequently develop HCC, with a higher concentration of the mutation in plasma enhancing predisposition for cancer development.

Detection of Epstein-Barr Virus DNA in Serum or Plasma for Nasopharyngeal Cancer: A Meta-Analysis

Studies have shown that the plasma or serum cell-free Epstein-Barr virus (EBV) DNA level might be a tumor marker for the diagnosis of nasopharyngeal carcinoma (NPC). The objective of this study was to evaluate the diagnostic value of the detection of EBV DNA in plasma or serum for NPC. Articles related to the diagnosis of NPC by the detection of EBV DNA in plasma or serum were retrieved from different databases. Sensitivity, specificity, summary receiver operator curves, and likelihood ratios were pooled to assess the diagnostic value of individual diagnostic tests. Fifteen studies were included in the meta-analysis. The pooled sensitivity and specificity were 89.1% (95% confidence interval [CI], 87.0%-90.9%) and 85.0% (95% CI, 83.0%-86.9%). The subgroup analysis regarding sample type found that the pooled sensitivity and specificity were 91.4% (95% CI, 89.0%-93.4%) and 93.2% (95% CI, 91.2%-95.0%) for the plasma group and 84.4% (95% CI, 79.9%-88.3%) and 76.0% (95% CI, 72.1%-79.6%) for the serum group. The detection of EBV DNA for the diagnosis of NPC has good sensitivity and specificity and might be helpful for the screening of NPC.

Quantification of Circulating Plasma DNA in Friedreich's Ataxia and Spinocerebellar Ataxia Types 2 and 12

DNA triplet repeat expansion-associated ataxias, Friedreich's ataxia, and different types of spinocerebellar ataxias (SCAs) are progressive multisystem neurodegenerative disorders. The diagnosis of this wide group of inherited ataxias is essentially based on clinical findings. Cell-free circulating DNA in plasma has been considered as a powerful tool in clinical diagnosis and prognosis of several human diseases. In the present study, clinically suspected patients were assessed on the International Co-operative Ataxia Rating Scale and further confirmed by molecular analysis of DNA triplet repeats. Quantification of plasma DNA using a highly sensitive and DNA-specific PicoGreen fluorescent assay was done. We found significantly high levels (p < 0.001) of plasma DNA of 167 ± 43 ng/mL in Friedreich's ataxia patients (n = 15), 148 ± 29 ng/mL in SCA2 patients (n = 10), and 137 ± 29 ng/mL in SCA12 patients (n = 25), whereas those of healthy controls (n = 20) was only 59 ± 15 ng/mL. Therefore, we were able to distinguish between ataxia patients and healthy controls using plasma DNA. Although the precise mechanism by which plasma DNA enters into circulation is not known, significantly higher concentrations of plasma DNA appears to be due to neuronal and muscular degeneration in these patients. Identification of genes in plasma DNA, which are overexpressed or novel, can be a promising tool for the prognosis of these diseases.

High incidence of cytomegalovirus, human herpesvirus-6, and Epstein-Barr virus reactivation in patients receiving cytotoxic chemotherapy for Adult T cell leukemia

The etiology of cytomegalovirus (CMV), human herpesvirus-6 (HHV-6), and Epstein-Barr virus (EBV) reactivation and the potential for complications following cytotoxic chemotherapy in the absence of allogeneic transplantation are not clearly understood. Patients with adult T cell leukemia (ATL) are susceptible to opportunistic infections. In this study, the incidence, kinetics and clinical significance of reactivation of CMV, HHV-6, and EBV in ATL patients were investigated. Viral DNA in a total of 468 plasma samples from 34 patients was quantified using real-time PCR. The probability of CMV, HHV-6, and EBV reactivation by 100 days after the start of chemotherapy was 50.6%, 52.3%, and 21.6%, respectively. Although most CMV reactivations were self-limited, plasma CMV DNA tended to persist or increase if the CMV DNA levels in plasma reached ≥ 10(4) copies/ml. CMV reactivation was negatively associated with survival, but the P-value for this association was near the borderline of statistical significance (P=0.052). One patient developed fatal interstitial pneumonia concomitant with peak CMV DNA accumulation (1.6 × 10(6) copies/ml plasma). Most HHV-6 and EBV reactivations were self-limited, and no disease resulting from HHV-6 or EBV was confirmed. HHV-6 and EBV reactivation were not associated with reduced survival (P=0.35 and 0.11, respectively). These findings demonstrated that subclinical reactivation of CMV, HHV-6, and EBV were common in ATL patients receiving chemotherapy. There were differences in the viral reactivation patterns among the three viruses. A CMV load ≥ 10(4) copies/ml plasma was indicative of subsequent exacerbation of CMV reactivation and developing serious clinical course.

Quantitative analysis of circulating DNA in plasma of patients with acute pancreatitis and its potential clinical value

Objective To quantitatively detect the circulating DNA in plasma of patients with acute pancreatitis and to evaluate its potential clinical values. Methods Blood samples collected from 40 patients with mild acute pancreatitis (MAP), 20 with severe acute pancreatitis (SAP) and 50healthy controls were extracted for DNA using genomic DNA extraction kit. The DNA level was detected by real-time fluorescence quantitative PCR assay. The clinical association of DNA level with acute pancreatitis was analyzed. The receiver operating characteristic (ROC) curve was set up. Results The median concentration of plasma DNA in SAP group was 24.84 ng/ml, which was significantly higher than that in MAP group (7.60 ng/ml, P=0.006) and the healthy controls (5.23 ng/ml, P=0.000). The median concentration of plasma DNA in patients with acute pancreatitis was higher than in healthy controls (P=0.006), however, there was no significant difference between MAP group and healthy controls (P=0.322).The area under the ROC curve performed by the plasma DNA from SAP and MAP groups was 0. 881(95% CI, 0.773-0.989). With a cutoff value of 11.20 ng/ml, the overall sensitivity was 19/20% and specificity was 72.5%. Plasma DNA level was found to be associated with APACHE-Ⅱ score (P=0.001), Ranson score (P=0. 013), serum Ca2+ level (P=0.000), and c-reactive protein levels (P=0.001). Conclusions Plasma DNA is correlated with the extent of pancreatitis. It can be used in monitoring the development of acute pancreatitis and may be a potential marker for early diagnosis of SAP. Key words: Pancreatitis,acute necrotizing; Polymerase chain reaction; DNA

Plasma DNA concentration as an early predictor of outcome in critically ill septic patients

Sepsis is associated with cell necrosis and apoptosis. Indeed, plasma DNA levels have been shown to be increased in patients with sepsis [1]. So we investigated the prognostic value of circulating levels of cell-free DNA in critically ill septic patients regarding the clinical course and final outcome.

Herpes Simplex Virus Load to Monitor Antiviral Treatment after Liver Transplantation for Acute Herpetic Hepatitis

Herpes simplex virus (HSV) hepatitis is an uncommon cause of acute liver failure (ALF), primarily affecting immunocompromised patients. So far, 148 cases have been published, of which 9 underwent liver transplantation (LT). The reported post-transplant survival is poor, with over 60% dying in the first year. Dosing and duration of antiviral therapy after LT are not established. Concerns include both the risk of hepatic recurrence after LT and emergence of viral resistance during prolonged therapy. HSV DNA plasma levels might be helpful to monitor therapeutic response and guide duration of therapy. We present a case of ALF complicating a primary HSV-1 infection in an immunocompetent host, who required emergency LT. We further discuss the value of measuring serial HSV DNA plasma loads to monitor antiviral therapy.

Plasma cell-free DNA in patients needing mechanical ventilation

IntroductionConcentrations of plasma cell-free DNA are increased in various diseases and have shown some prognostic value in many patient groups, including critically ill patients. Pathophysiological processes behind the need for mechanical ventilation and the treatment itself could raise plasma levels of cell-free DNA. We evaluated levels of plasma cell-free DNA and their prognostic value in patients needing mechanical ventilation.MethodsWe studied prospectively 580 mechanically ventilated critically ill patients. Blood samples were taken at study admission (Day 0) and on Day 2. Plasma cell-free DNA concentrations were measured by real-time quantitative PCR assay for the β-globin gene and are expressed as genome equivalents (GE)/ml.ResultsMedian (interquartile range, IQR) plasma cell-free DNA concentration was 11,853 GE/ml (5,304 to 24,620 GE/mL) at study admission, and 11,610 GE/mL (6,411 to 21,558 GE/mL) on Day 2. Concentrations at admission were significantly higher in 90-day non-survivors than survivors, 16,936 GE/mL (7,262 to 46,866 GE/mL) versus 10,026 GE/mL (4,870 to 19,820 GE/mL), P < 0.001. In a multivariate logistic regression analysis plasma cell-free DNA concentration over 16,000 GE/ml remained an independent predictor of 90-day mortality (adjusted odds ratio 2.16, 95% confidence interval CI 1.37 to 3.40). Positive likelihood ratio of plasma cell-free DNA at admission for the prediction of 90-day mortality was 1.72 (95% CI 1.40 to 2.11).ConclusionsPlasma levels of cell-free DNA were significantly higher in non-survivors than survivors. Plasma DNA level at baseline was an independent predictor of 90-day mortality. However, its clinical benefit as a prognostic marker seems to be limited.

Soluble CD30: A serum marker for Epstein–Barr virus‐associated lymphoproliferative diseases

The soluble form of CD30 (sCD30), a member of tumor necrosis factor receptor superfamily, has been used as a marker of disease activity in various lymphomas. Epstein-Barr virus (EBV) is a potent stimulator of CD30 expression. The study aims to evaluate whether sCD30 can be used as a diagnostic marker for EBV-associated infectious mononucleosis (IM) and post-transplant lymphoproliferative disease (PTLD). Plasma from EBV seropositive healthy controls (N = 90), acute IM patients (n = 90), non-PTLD heart/lung transplant recipients (N = 30) and EBV-positive PTLD patients (N = 23) was tested for sCD30 using a commercially available ELISA kit. EBV DNA was tested by real time quantitative polymerase chain reaction assay. Significantly higher sCD30 levels were observed in acute IM patients (median 242.9 ng/ml) compared to EBV seropositive controls (median 15.7 ng/ml; P < 0.0001). These levels were highest in IM patients within 14 days of onset of illness. PTLD patients had significantly higher sCD30 levels (median 94 ng/ml) than healthy controls (P < 0.0001) and transplant patients (median 27 ng/ml; P = 0.0007). EBV DNA was detected mostly in acute IM and PTLD patients. In both cases there was a significant correlation between sCD30 and EBV DNA levels in plasma (P < 0.0001). This study demonstrates that sCD30 and EBV DNA levels can be used as potential markers for diagnosis of IM and PTLD.