Paper-based microfluidic electro-analytical device (PMED) for magneto-assay automation: Towards generic point-of-care diagnostic devices.

Rapid diagnostic tests (RDTs) for point-of-care (POC) testing of infectious diseases are popular because they are easy to use. However, RDTs have limitations such as low sensitivity and qualitative responses that rely on subjective visual interpretation. Additionally, RDTs are made using paper-bound reagents, which leads to batch-to-batch variability, limited storage stability and detection of only the analytes they were designed for. This work presents the development of a versatile technology, based on short magneto-assays and inexpensive paper-based microfluidic electro-analytical devices (PMEDs). PMEDs were produced locally using low-cost equipment, they were stable at room temperature, easy to use, and provided quantitative and objective results. The devices served to detect alternatively a variety of magneto-assays, granting quantitation of streptavidin-HRP, biotinylated HRP and Pasmodium falciparum lactate dehydrogenase (Pf-LDH) in less than 25 min, using either commercial or customized screen-printed electrodes and measurement equipment. Furthermore, Pf-LDH detection in diluted lysed whole blood displayed a linear response between 3 and 25 ng mL-1, detection and quantification limits ranging between 1 and 3 ng mL-1 and 6-12 ng mL-1, respectively, and provided results that correlated with those of the reference ELISA. In short, this technology is versatile, simple, and highly cost-effective, making it perfect for POC testing.

Malaria quantitative POC testing using magnetic particles, a paper microfluidic device and a hand-held fluorescence reader.

A point-of-care (POC) device is reported for highly sensitive and selective detection of Plasmodium falciparum lactate dehydrogenase (Pf-LDH), a biomarker of malaria infection, based on a single-step magneto-immunoassay, a single-use microfluidic paper device and a customized hand-held fluorescence reader. The single-step magneto-immunoassay consists in a single 5-min incubation of immuno-modified magnetic particles (c-MAb-MPs), biotinylated detection antibody (bd-MAb), and an enzymatic signal amplifier (Poly-HRP). After on-chip MP concentration and washing, signal generation is achieved by adding a fluorescent enzymatic substrate (QuantaRed). Fluorescence signal is measured using a low-cost customized, portable, and sensible fluorescent detector. The POC affords quantitative Pf-LDH detection in <20 min, with a detection limit of 0.92 ng mL-1 (equivalent to 4.6 parasites µL-1). Furthermore, Pf-LDH quantitation in clinical samples correlates with that provided by the reference ELISA, is more sensitive than a commercial rapid diagnostic test (RDT) and entails little user intervention. These results show that fluorescent paper-based microfluidic devices can be exploited to simplify magneto-immunoassay handling, taking this type of test closer to the requirements of POC testing.

Diagnostic benefits of adding EspC, EspF and Rv2348-B to the QuantiFERON Gold In-tube antigen combination.

Interferon (IFN)-γ release assays (IGRAs) are used to diagnose latent tuberculosis (TB) infection (LTBI). To improve the accuracy of these tests, different approaches, such as alternative cytokine detection and using different antigens, are considered. Following this purpose, this study aims to evaluate the addition of EspC, EspF and Rv2348-B to those present in the QuantiFERON-TB Gold In-Tube (QFN-G-IT). We included 115 subjects: 74 active TB patients, 17 LTBI individuals and 24 healthy controls. Whole blood samples were collected in QFN-G-IT and in-house tubes containing different combinations of EspC, EspF and Rv2348-B, together with ESAT-6, CFP-10, and TB7.7. After overnight incubation at 37 ºC, plasma was harvested and IFN-γ quantified. IFN-γ levels in the QFN-G-IT and in-house tubes correlated very good (Spearman Rho(r) > 0.86). In-house antigen combinations distinguished healthy individuals from those with active TB and LTBI (specificities and sensitivities higher than 87.5% and 96.3%, respectively [AUC > 0.938]). Adding EspC, EspF and Rv2348-B, increased the sensitivity of the test, being the addition of EspC and Rv2348-B the combination that yielded a higher sensitivity with no specificity loss. Addition of these antigens could improve diagnosis in patients with impaired or immature immune response who are at high risk of developing TB.

Tuberculosis, COVID-19 and migrants: Preliminary analysis of deaths occurring in 69 patients from two cohorts.

Little is known about the relationship between the COVID-19 and tuberculosis (TB). The aim of this study is to describe a group of patients who died with TB (active disease or sequelae) and COVID-19 in two cohorts. Data from 49 consecutive cases in 8 countries (cohort A) and 20 hospitalised patients with TB and COVID-19 (cohort B) were analysed and patients who died were described. Demographic and clinical variables were retrospectively collected, including co-morbidities and risk factors for TB and COVID-19 mortality. Overall, 8 out of 69 (11.6%) patients died, 7 from cohort A (14.3%) and one from cohort B (5%). Out of 69 patients 43 were migrants, 26/49 (53.1%) in cohort A and 17/20 (85.0%) in cohort B. Migrants: (1) were younger than natives; in cohort A the median (IQR) age was 40 (27-49) VS. 66 (46-70) years, whereas in cohort B 37 (27-46) VS. 48 (47-60) years; (2) had a lower mortality rate than natives (1/43, 2.3% versus 7/26, 26.9%; p-value: 0.002); (3) had fewer co-morbidities than natives (23/43, 53.5% versus 5/26-19.2%) natives; p-value: 0.005). The study findings show that: (1) mortality is likely to occur in elderly patients with co-morbidities; (2) TB might not be a major determinant of mortality and (3) migrants had lower mortality, probably because of their younger age and lower number of co-morbidities. However, in settings where advanced forms of TB frequently occur and are caused by drug-resistant strains of M. tuberculosis, higher mortality rates can be expected in young individuals.

Efficacy and safety assessment of different dosage of benznidazol for the treatment of Chagas disease in chronic phase in adults (MULTIBENZ study): study protocol for a multicenter randomized Phase II non-inferiority clinical trial.

BACKGROUND: Chagas disease (CD) continues to be a neglected infectious disease with one of the largest burdens globally. Despite the modest cure rates in adult chronic patients and its safety profile, benznidazole (BNZ) is still the drug of choice. Its current recommended dose is based on nonrandomized studies, and efficacy and safety of the optimal dose of BNZ have been scarcely analyzed in clinical trials. METHODS/DESIGN: MULTIBENZ is a phase II, randomized, noninferiority, double-blind, multicenter international clinical trial. A total of 240 patients with Trypanosoma CD in the chronic phase will be recruited in four different countries (Argentina, Brazil, Colombia, and Spain). Patients will be randomized to receive BNZ 150 mg/day for 60 days, 400 mg/day for 15 days, or 300 mg/day for 60 days (comparator arm). The primary outcome is the efficacy of three different BNZ therapeutic schemes in terms of dose and duration. Efficacy will be assessed according to the proportion of patients with sustained parasitic load suppression in peripheral blood measured by polymerase chain reaction. The secondary outcomes are related to pharmacokinetics and drug tolerability. The follow-up will be 12 months from randomization to end of study participation. Recruitment was started in April 2018. CONCLUSION: This is a clinical trial conducted for the assessment of different dose schemes of BNZ compared with the standard treatment regimen for the treatment of CD in the chronic phase. MULTIBENZ may help to clarify which is the most adequate BNZ regimen in terms of efficacy and safety, predicated on sustained parasitic load suppression in peripheral blood. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03191162. Registered on 19 June 2017.

QTc and anti-tuberculosis drugs: a perfect storm or a tempest in a teacup? Review of evidence and a risk assessment.

The changing epidemiology of spinal tuberculosis: the influence of international immigration in Catalonia, 1993-2014.

The overall incidence of spinal tuberculosis (TB) appears to be stable or declining in most European countries, but with an increasing proportion of cases in the foreign-born populations. We performed a retrospective observational study (1993-2014), including all cases of spinal TB diagnosed at a Barcelona hospital to assess the epidemiological changes. Fifty-four episodes (48·1% males, median age 52 years) of spinal TB were diagnosed. The percentage of foreign-born residents with spinal TB increased from 14% to 45·2% in the last 10 years (P = 0·017). Positive Mycobacterium tuberculosis testing in vertebral specimens was 88·2% (15/17) for GeneXpert MTB/RIF. Compared with natives, foreign-born patients were younger (P < 0·01) and required surgery more often (P = 0·003) because of higher percentages of paravertebral abscess (P = 0·038), cord compression (P = 0·05), and persistent neurological sequelae (P = 0·05). In our setting, one-third of spinal TB cases occurred in non-native residents. Compared with natives, foreign-born patients were younger and had greater severity of the disease. The GeneXpert MTB/RIF test may be of value for diagnosing spinal TB.

Pharmacokinetics of Benznidazole in Healthy Volunteers and Implications in Future Clinical Trials.

Despite its toxicity and low efficacy in the chronic phase, benznidazole is the drug of choice in Chagas disease. Scarce information about pharmacokinetics and pharmacodynamics of benznidazole has been published. We performed a phase I, open-label, nonrandomized pharmacokinetic study of benznidazole (Abarax) conducted with 8 healthy adult volunteers at the Infectious Diseases Department of the Vall d'Hebron University Hospital (Barcelona, Spain). The separation and detection of benznidazole were performed on a Waters Acquity ultraperformance liquid chromatography system (UPLC) coupled with a Waters Xevo TQ MS triple quadrupole mass spectrometer. The pharmacokinetic parameters were calculated based on a noncompartmental body model using Phoenix WinNonlin version 6.3 software. Furthermore, computational simulations were calculated for the multiple-dose administration at two dose regimens: 100 mg of benznidazole administered every 8 h and 150 mg of benznidazole administered every 12 h. After benznidazole administration, the median area under the concentration-time curve from time zero to time t (AUC0-t ) and extrapolated to infinity (AUC0-∞) were about 46.4 µg · h/ml and 48.4 µg · h/ml, respectively. Plasma benznidazole concentrations peaked at 3.5 h, with maximal concentrations of 2.2 µg/ml, and benznidazole exhibited a terminal half-life of 12.1 h. The median maximum concentration (Cmax) of benznidazole was lower in men than in women (1.6 versus 2.9 µg/ml), and median volume of distribution (V) as a function of bioavailability (F) was higher in men than in women (125.9 versus 88.6 liters). In conclusion, dose regimens (150 mg/12 h or 100 mg/8 h) reached a steady-state range concentration above of the minimum experimental therapeutic dose. Sex differences in the benznidazole pharmacokinetics were observed; mainly, men had lower Cmax and higher V/F than women.

Serodiscordance in chronic Chagas disease diagnosis: a real problem in non-endemic countries.

According to the WHO, chronic Chagas disease (CD) diagnosis is based on two serological techniques. To establish a definitive diagnosis, the results must be concordant. In cases of discordances, the WHO proposes repeating serology in a new sample, and if results remain inconclusive, a confirmatory test should be performed. This study, conducted at two Tropical Medicine Units in Europe over 4 years, aims to assess the diagnostic yield of TESA- (trypomastigote excreted-secreted antigens) blot as a confirmatory technique in patients with inconclusive and discordant results. Of 4939 individuals screened, 1124 (22.7%) obtained positive results and 165 (3.3%) discordant results. Serology was repeated in 88/165 sera and discrepancies were solved in 25/88 (28.4%) cases. Patients without a definitive diagnosis were classified in two different groups: Group 1, including patients with inconclusive results despite retesting (n = 63), and Group 2, including patients with discordant results not retested (n = 77). TESA-blot was performed for all of Group 1 and 39/77 of Group 2 and was positive for 33/63 (52.4%) and 21/39 (53.8%), respectively. Analysis of Group 1 results showed a moderate agreement between results of the ELISA based on native antigen and TESA-blot (κ 0.53). In contrast, a clear disagreement was observed between the ELISA based on recombinant antigens and TESA-blot (κ <0). A sizeable proportion of patients are suspected to have CD with inconclusive results or in whom re-testing is not feasible. TESA-blot was positive in half of these patients, highlighting the need for a confirmatory assay in European centres caring for exposed individuals.

Toxic Profile of Benznidazole in Patients with Chronic Chagas Disease: Risk Factors and Comparison of the Product from Two Different Manufacturers.

Benznidazole is considered the first-line treatment option against Chagas disease. The major drawback of benznidazole is its toxicity profile. The main objectives of this study were to describe the adverse events (AEs) in patients with chronic Chagas disease treated with benznidazole, determine the risk factors involved and compare the toxic profiles of two different preparations of the drug from ELEA and Roche. A total of 746 patients were diagnosed with Chagas disease in a 5-year period, and of these 472 were treated with benznidazole. A high proportion of patients (n = 360 [76%]) suffered AEs, the most frequent being those related to hypersensitivity (52.9% of patients), headache (12.5%), and epigastric pain (10.4%). In 72 (12.7%) cases, treatment was discontinued. Overall, women had a higher incidence of AEs compared to men (81.3% versus 66%, P = 0.001) and were subject to higher levels of hypersensitivity-related events. Dermatological events, digestive tract manifestations, and general symptoms had a greater likelihood to appear around day 10 and neurological AEs around day 40 after starting treatment. With respect to liver function and hematological tests, the majority of patients did not suffer significant perturbation of liver enzymes or altered blood cell counts. However, 14 patients suffered from neutropenia, and 14 patients had aminotransferase levels that were more than four times the upper limit of the normal range. Patients treated with the ELEA benznidazole product experienced more arthromyalgia, neutropenia, and neurological disorders (mainly paresthesias) than those treated with the Roche product. Both drug products resulted in approximately the same percentage of permanent withdrawals.

Immunosuppression and Chagas disease; experience from a non-endemic country.

Reactivation of Chagas disease in the chronic phase may occur when immunosuppression is established, sometimes resulting in high parasitaemia and severe clinical manifestations such as meningitis and meningoencephalitis. Although this situation is being increasingly described, there is still scarce information. This retrospective observational study was performed in three Tropical Medicine Units of Barcelona (Spain) included in the International Health Programme of the Catalan Health Institute (PROSICS). The objective of the study was to describe epidemiological, clinical, microbiological, prognostic and therapeutic data from patients with Chagas disease and any kind of immunosuppressive condition attended in these three institutions from January 2007 to October 2014. From 1823 patients with Chagas disease attending these three centres during the study period, 38 (2%) had some kind of immunosuppressive condition: 12 patients had human immunodeficiency virus infection, 8 patients had neoplasia, 4 patients underwent organ transplantation and 14 patients had an autoimmune disease. Eight (21.1%) patients had cardiac involvement, and six (15.8%) patients had gastrointestinal involvement. Acute Trypanosoma cruzi infection was detected in two Spanish patients. Thirty-one (81.6%) patients received treatment with benznidazole, of whom 17 (54.8%) had some kind of adverse event. No patient had a severe manifestation or reactivation of Chagas disease. Patients with Chagas disease under immunosuppressive conditions are being increasingly described, especially in non-endemic countries. More information about this topic is required and international consensus in the diagnosis, treatment and follow up of these patients must be established to reduce the morbidity and mortality.

Anti-SSA/Ro52 autoantibodies in scleroderma: results of an observational, cross-sectional study.

OBJECTIVES: To date, the diagnostic utility of anti-SSA/Ro52 autoantibodies in scleroderma and the association of them with certain clinical manifestations, particularly inflammatory myositis, are still controversial. This paper aims to assess the correlation between the presence of anti-SSA/Ro52 antibodies and the demographic, clinical and prognosis characteristics of patients with systemic sclerosis (SSc). METHODS: This is a retrospective, cross-sectional and observational study in patients with SSc. Baseline demographic and clinical characteristics were recorded. Presence of anti-SSA/Ro52, anti-SSA/Ro, anti-SSB/La, snRNP/Sm, anti-centromere, anti-Scl-70 and anti-PM-Scl were analysed by immunoblot, and antinuclear antibodies (ANA) by indirect immunofluorescence. Statistical analysis was performed with PASW Statics 18 software. RESULTS: A total of 132 consecutive patients with analysis of anti-SSA/Ro52 antibodies were selected from a Spanish cohort of 408 patients with SSc, 87.1% of them being women. About half of patients had the limited form (51.5%), followed by diffused form (18.9%), sclerosis sine scleroderma (22.7%), and pre-scleroderma (6.8%). Prevalence of anti-SSA/Ro52 was 35.6%. No association between anti-SSA/Ro52 and clinical manifestations was found, while detection of anti-SSA/Ro52 was significantly associated with the presence of anti-Ro. CONCLUSIONS: The results of our study show that anti-SSA/Ro52 antibodies are often found in SSc patients. No clinical manifestations, including inflammatory myopathy, were related with anti-SSA/Ro antibodies.

Trypanosoma cruzi infection in a non-endemic country: epidemiological and clinical profile.

Chagas disease has been increasingly diagnosed in non-endemic countries. This is a prospective observational study performed at the Tropical Medicine Units of the International Health Program of the Catalan Health Institute, Barcelona (PROgrama de Salud Internacional del Instituto Catalán de la Salud, PROSICS Barcelona, Spain), that includes all patients with Chagas disease who attended from June 2007 to May 2012. Clinical and epidemiological data were collected. Overall, 1274 patients were included, the mean age of the patients was 37.7 years, 67.5% were women and 97% came from Bolivia. Thirteen patients had immunosuppressive conditions. The prevalence of cardiac involvement was 16.9%, lower than in previous studies performed in endemic areas (20-60%). Cardiac alterations were found in 33.8% of symptomatic and 14.1% of asymptomatic patients. The prevalence of digestive involvement was 14.8%. The rate of digestive involvement is very different among previous studies because of different diagnostic tools and strategies used. Barium enema alterations were found in 21.4% of symptomatic and 10.3% of asymptomatic patients, and oesophageal alterations were found in 3.7% of symptomatic and in 2.3% of asymptomatic patients. As shown in previous studies, Chagas disease in non-endemic countries affects younger patients and has lower morbidity.