Confirmatory Test For Diagnosis Research Articles

Molecular detection of Wuchereria bancrofti, Loa loa and Mansonella perstans from dried blood spots taken from pregnant women in rural Burkina Faso

Introduction: Human filariasis causes high morbidity and severe illness. There is a link between helminth infection and anemia. The objective of this study was to estimate the prevalence of blood-dwelling microfilariae among pregnant women in Burkina Faso using a molecular technique and attempt to find an association between anemia and filarial infection. Methods: A total of 1018 dried blood spot samples (DBS) were collected from pregnant women at the Health District of Nanoro. The DNA was isolated from DBS samples using a rapid and simple method. Afterward, the isolated DNA was assayed using the Filaria real-time PCR (F-RT-PCR) method. Results: Ten F-RT-PCR-positive samples were obtained as follows: two W. bancrofti (0.2%), four L. loa (0.39%), and four M. perstans (0.39%). No concomitant filarial infections were detected, as well as no coinfections between filarial disease and malaria. There was no link between the presence of W. bancrofti, L. loa, or M. perstans and anemia in pregnant women. Conclusions: The prevalence and intensity of human filariasis in this study were low for all of the samples in which microfilariae were detected. The F-RT-PCR can be a confirmatory test for diagnosis in remote areas due to its effectiveness in detecting and differentiating, both sensitively and specifically, a wide range of filarial parasites.

Diagnostic Utility of Red Blood Cell Indices-Derived Formulas in Discriminating Beta-Thalassemia Trait from Iron Deficiency Anemia

Abstract Background The two most frequently encountered microcytic hypochromic anemias are iron deficiency anemia (IDA) and β-thalassemia trait (β-TT) which need relatively expensive laboratory tests to be differentiated. Objectives This study aims at evaluating the diagnostic utility of different discrimination formulas derived from red blood cell indices from complete blood count in the differentiation of β-TT from IDA. Subjects and Methods This study was conducted on 140 subjects; 40 healthy individuals and 100 patients (60 IDA and 40 β-TT) recruited from outpatient clinics of Ain Shams University Hospitals. They were 45 males and 95 females (M: F 1:2.1), their ages ranged from 19 to 63 years. Patients were subjected to measurement of CBC, iron profile, Hb electrophoresis and HPLC and calculation of RBC indices- derived formulas. Results Comparative studies of different formulas among the studied group shows that England and Fraser (E & F), MDHL, MCHD, MCI and Zaghloul 2 can significantly differentiate between β-TT patients and IDA patients (P was 0.009, 0.008, 0, 0.001 and 0.050 respectively). Evaluation of diagnostic performance (efficacy) of the studied RBCs formulas showed that Zaghloul 2 is the best index in discriminating β-TT from IDA at cut off 66.61 with specificity (97.5%), sensitivity (76.7%) and diagnostic efficacy (85%). This was followed by MCI at cut off 22.73 with specificity (57.5%), sensitivity (85.0%) and diagnostic efficacy (74. %). Then they are followed by MDHL at cut off 1.487 with specificity (50.0%), sensitivity (86.7%) and diagnostic efficacy (72.0), then England and Fraser with cut off 8.9 with specificity (50.0%), sensitivity (80.0%) and diagnostic efficacy (68.0%), and lastly MCHD with cut off 0.296 with specificity (72.5%), sensitivity (61.7%) and diagnostic efficacy (66.0%). Values above these cut off levels indicate β-TT whereas values below these levels indicate IDA except for E&F formula where <8.9 cut off indicate β-TT and >8.9 indicate IDA. Conclusion Zaghloul 2 formula showed the highest efficacy in the differentiation of β-TT from IDA (85%) followed by MCI (74%) and MDHL (72%) then England and Fraser (68%) and lastly MCHD (66%). They can be used for screening in big population, being simple and inexpensive, and then followed by the usual confirmatory tests. Their real use comes in rural areas and primary care facilities where only red blood cell indices are handy. They can be calculated and the cases can be referred to secondary health care to take the confirmatory tests for diagnosis.

Significance of Discordant Results: between Confirmatory Tests in Diagnosis of Primary Aldosteronism

Context: Current clinical guidelines recommend confirmation of positive result in at least one confirmatory test in the diagnosis of primary aldosteronism (PA). Clinical implication of multiple confirmatory tests has not been established, especially when patients show discordant results. Objective: The aim of the present study was to explore the role of two confirmatory tests in subtype diagnosis of PA. Design: Retrospective cross-sectional study. Setting: The study was conducted at two referral centers. Participants and Method: We identified 360 hypertensive patients who underwent both captopril challenge test (CCT) and saline infusion test (SIT) and exhibited at least one positive result. Among them, we studied 193 patients with PA whose data were available for subtype diagnosis based on adrenal vein sampling (AVS). Main Outcome Measure: The prevalence of bilateral subtype on AVS according to the results of the confirmatory tests. Results: Of patients studied, 127 were positive for both CCT and SIT (double-positive), while 66 were positive for either CCT or SIT (single-positive) (n = 34 and n = 32, respectively). Altogether, 135 were diagnosed with bilateral subtype on AVS. The single-positive patients had milder clinical features of PA than the double-positive patients. The prevalence of bilateral subtype on AVS was significantly higher in the single-positive patients than in the double-positive patients. (63/66 [95.5%] vs. 72/127 [56.7%], P < 0.01). Several clinical parameters were different between CCT single-positive and SIT single-positive patients. Conclusion: Patients with discordant results between CCT and SIT have a high probability of bilateral subtype of PA on AVS.

Confirmatory tests for diagnosis of primary aldosteronism among Chinese hypertensives

Confirmatory tests for diagnosis of primary aldosteronism among Chinese hypertensives

Use of recombinant proteins MPB70 or MPB83 as capture antigens in ELISAs to confirm bovine tuberculosis infections in Brazil

The objective was to evaluate the use of two indirect IgG-ELISA tests (with recombinant proteins MPB70 or MPB83, respectively, as capture antigens) as confirmatory tests for diagnosis of bovine tuberculosis in a herd of naturally infected dairy cows. Results for ELISA-MPB70 and ELISA-MPB83 were similar (kappa statistic=0.92) on Days 0 (day of intradermal injection with purified protein derivatives, PPD), 7, and 21. The kappa statistic between ELISA and the Comparative Intradermal Tuberculin Test, as well as ELISA sensitivity and specificity (relative to culture or PCR as standards) were: 0.7, 34.4% and 75% on Day 0; 0.25, 53.8% and 66.6% on Day 7; and 0.01, 1.8% and 77.7% on Day 21, respectively. In conclusion, although ELISAs using MPB70 or MPB83 as antigens were not reliable indicators of infection status, especially on Days 7 and 21, they were of potential value as complementary tools to intradermal PPD testing.