Diagnostic Accuracy of the Cepheid 3-gene Host Response Fingerstick Blood Test in a Prospective, Multi-site Study: Interim Results.

BACKGROUND: The development of a fast and accurate, non-sputum-based point-of-care triage test for tuberculosis (TB) would have a major impact on combating the TB burden worldwide. A new fingerstick blood test has been developed by Cepheid (the Xpert MTB Host Response [MTB-HR] prototype), which generates a "TB score" based on messenger RNA (mRNA) expression of 3 genes. Here we describe the first prospective findings of the MTB-HR prototype. METHODS: Fingerstick blood from adults presenting with symptoms compatible with TB in South Africa, The Gambia, Uganda, and Vietnam was analyzed using the Cepheid GeneXpert MTB-HR prototype. Accuracy of the Xpert MTB-HR cartridge was determined in relation to GeneXpert Ultra results and a composite microbiological score (GeneXpert Ultra and liquid culture) with patients classified as having TB or other respiratory diseases (ORD). RESULTS: When data from all sites (n = 75 TB, 120 ORD) were analyzed, the TB score discriminated between TB and ORD with an area under the curve (AUC) of 0.94 (95% confidence interval [CI], .91-.97), sensitivity of 87% (95% CI, 77-93%) and specificity of 94% (88-97%). When sensitivity was set at 90% for a triage test, specificity was 86% (95% CI, 75-97%). These results were not influenced by human immunodeficiency virus (HIV) status or geographical location. When evaluated against a composite microbiological score (n = 80 TB, 111 ORD), the TB score was able to discriminate between TB and ORD with an AUC of 0.88 (95% CI, .83-.94), 80% sensitivity (95% CI, 76-85%) and 94% specificity (95% CI, 91-96%). CONCLUSIONS: Our interim data indicate the Cepheid MTB-HR cartridge reaches the minimal target product profile for a point of care triage test for TB using fingerstick blood, regardless of geographic area or HIV infection status.

Detection of immunoglobulin response to COVID-19 vaccination using a novel rapid fingerstick assay.

Coronavirus Disease 2019 (COVID-19) emerged as a global pandemic resulting in significant mortality and morbidity. COVID-19 vaccines have been shown to be highly effective in preventing COVID-19 infections and significantly reducing disease severity and mortality. We report on a novel COVID-19 antibody assay using a unique platform to rapidly detect SARS-CoV-2 antibodies with a drop of fingerstick blood in a subject following COVID-19 vaccination. We show early detection of SARS-CoV-2 antibodies post vaccination and persistence of detectable antibodies for at least 6 months. Rapid point of care COVID-19 antibody tests might have a role in assessing the appearance and durability of immune response following COVID-19 vaccination.

URGENT 1.5: diagnostic accuracy of the modified HEART score, with fingerstick point-of-care troponin testing, in ruling out acute coronary syndrome.

BACKGROUND: The HEART score is a validated risk stratification tool for chest pain patients presenting to the emergency department and was recently investigated for implementation in a pre-hospital setting. Fingerstick (capillary blood) point-of-care (POC) troponin testing enables quick measurements outside the hospital and seems easier to implement than the current venous blood sampling techniques. This study investigates the diagnostic accuracy of the modified HEART score, integrating fingerstick POC troponin testing, in ruling out acute coronary syndrome (ACS). METHODS: The data of 96 patients with chest pain, included in a study investigating a novel POC troponin device under development at the cardiac emergency department, were analysed retrospectively. Based on the patients' admission data and capillary POC high-sensitivity troponin I (hs-cTnI) results, the modified HEART score was determined. The outcome measure, for evaluating the diagnostic accuracy of the modified HEART score, was the occurrence of ACS. RESULTS: Of the total study population, 33 patients (34%) were diagnosed with ACS. Seventeen patients (18%) were classified as low risk (0-3 points) and one patient (6%) in this group was diagnosed with ACS. The sensitivity and negative predictive value of the modified HEART score was 97.0 and 97.6%, respectively. CONCLUSION: The modified HEART score, integrating capillary POC hs-cTnI results, is a promising tool for ruling out ACS in patients with chest pain presenting to the cardiac emergency department. These results encourage prospective investigation into the integration of fingerstick POC troponin testing in the modified HEART score in a pre-hospital setting.

Development and clinical application of a rapid IgM-IgG combined antibody test for SARS-CoV-2 infection diagnosis.

The outbreak of the novel coronavirus disease (COVID-19) quickly spread all over China and to more than 20 other countries. Although the virus (severe acute respiratory syndrome coronavirus [SARS-Cov-2]) nucleic acid real-time polymerase chain reaction (PCR) test has become the standard method for diagnosis of SARS-CoV-2 infection, these real-time PCR test kits have many limitations. In addition, high false-negative rates were reported. There is an urgent need for an accurate and rapid test method to quickly identify a large number of infected patients and asymptomatic carriers to prevent virus transmission and assure timely treatment of patients. We have developed a rapid and simple point-of-care lateral flow immunoassay that can detect immunoglobulin M (IgM) and IgG antibodies simultaneously against SARS-CoV-2 virus in human blood within 15 minutes which can detect patients at different infection stages. With this test kit, we carried out clinical studies to validate its clinical efficacy uses. The clinical detection sensitivity and specificity of this test were measured using blood samples collected from 397 PCR confirmed COVID-19 patients and 128 negative patients at eight different clinical sites. The overall testing sensitivity was 88.66% and specificity was 90.63%. In addition, we evaluated clinical diagnosis results obtained from different types of venous and fingerstick blood samples. The results indicated great detection consistency among samples from fingerstick blood, serum and plasma of venous blood. The IgM-IgG combined assay has better utility and sensitivity compared with a single IgM or IgG test. It can be used for the rapid screening of SARS-CoV-2 carriers, symptomatic or asymptomatic, in hospitals, clinics, and test laboratories.

Glucose monitoring from gingival crevicular fluid blood among chronic periodontitis patients at Ar Rass, Saudi Arabia.

Gingival crevicular fluid blood (GCFB), during periodontal probing is useful to assess blood sugar levels using a glucometer. Hence, blood glucose levels in chronic periodontitis with and without diabetes were measured using gingival crevicular fluid and compared to finger stick blood glucose levels (FSBG). A total of 48 patients (24 diabetics and 24 non-diabetics) with chronic periodontitis who matched the inclusion criteria were divided into two groups, Group I and Group II, respectively. The entire patient's plaque and Russel's periodontal indices were recorded and a glucometer was used to measure random blood glucose from the gingival crevicular fluid and finger pricks. A positive association between the blood glucose level measured by a fingerstick and the gingival crevicular fluid is observed. Thus, GCFB can be used as a reliable chairside diagnostic technique for diagnosis diabetes in a dental setting.

Large-volume RT-LAMP enables extraction-free amplification of HIV RNA from fingerstick plasma.

BACKGROUND: Point-of-care (POC) nucleic acid amplification tests (NAAT) can significantly expand testing coverage, which is critical for infectious disease diagnostics and monitoring. The development of various isothermal amplification techniques greatly simplifies NAATs, but the cumbersome nucleic acid extraction step remains a bottleneck for the POC. Alternatively, extraction-free amplification, where crude samples are directly added into the assay, substantially simplifies the workflow. However, sample dilution is often needed in extraction-free amplification to reduce assay inhibition from sample matrices. Since NAATs are typically run at small volumes around 20 µL, the input sample quantity is therefore limited, resulting in an inevitable sensitivity loss. RESULTS: Here we explore the potential to perform isothermal amplification in larger reaction volumes to accommodate larger sample quantities, thereby improving sensitivity in extraction-free amplification. We demonstrated the approach by developing large-volume reverse transcription loop-mediated isothermal amplification (RT-LAMP) for HIV RNA detection from fingerstick plasma. We found that LAMP at reaction volumes up to 1 mL maintained the same performance. We then identified plasma dilution conditions needed to maintain the limit of detection in RT-LAMP. Subsequently, using inactivated HIV virus, we showed the successful detection of 24 HIV RNA copies in a 500 µL RT-LAMP reaction in the presence of 20 µL plasma (fingerstick volumes), translating to a viral load of 1200 copies per mL. To reduce the increased reagent cost with expanded reaction volumes, we further identified lower-cost reagents with maintained assay performance. Moreover, we showed that large-volume LAMP, compared to 20 µL reactions, could tolerate higher concentrations of various inhibitors in the sample, such as albumin and GuSCN. SIGNIFICANCE AND NOVELTY: NAATs are conventionally conducted at small reaction volumes. Here we demonstrated that LAMP can be run at large reaction volumes (over 100 µL) with maintained assay performance, allowing sample inhibition to be mitigated while accommodating larger sample quantities. The same strategy of expanding reaction volumes could be applied to other isothermal amplification methods and various POC applications, to streamline test workflows and/or improve assay sensitivity.

Molecular Gene Expression Testing to Identify Alzheimer's Disease with High Accuracy from Fingerstick Blood.

Background: There is no molecular test for Alzheimer's disease (AD) using self-collected samples, nor is there a definitive molecular test for AD. We demonstrate an accurate and potentially definitive TempO-Seq® gene expression test for AD using fingerstick blood spotted and dried on filter paper, a sample that can be collected in any doctor's office or can be self-collected. Objective: Demonstrate the feasibility of developing an accurate test for the classification of persons with AD from a minimally invasive sample of fingerstick blood spotted on filter paper which can be obtained in any doctor's office or self-collected to address health disparities. Methods: Fingerstick blood samples from patients clinically diagnosed with AD, Parkinson's disease (PD), or asymptomatic controls were spotted onto filter paper in the doctor's office, dried, and shipped to BioSpyder for testing. Three independent patient cohorts were used for training/retraining and testing/retesting AD and PD classification algorithms. Results: After initially identifying a 770 gene classification signature, a minimum set of 68 genes was identified providing classification test areas under the ROC curve of 0.9 for classifying patients as having AD, and 0.94 for classifying patients as having PD. Conclusions: These data demonstrate the potential to develop a screening and/or definitive, minimally invasive, molecular diagnostic test for AD and PD using dried fingerstick blood spot samples that are collected in a doctor's office or clinic, or self-collected, and thus, can address health disparities. Whether the test can classify patients with AD earlier then possible with cognitive testing remains to be determined.

Point-of-care HCV RNA testing improves hepatitis C testing rates and allows rapid treatment initiation among people who inject drugs attending a medically supervised injecting facility.

BACKGROUND: To achieve hepatitis C virus (HCV) elimination targets, simplified care engaging people who inject drugs is required. We evaluated whether fingerstick HCV RNA point-of-care testing (PoCT) increased the proportion of clients attending a supervised injecting facility who were tested for hepatitis C. METHODS: Prospective single-arm study with recruitment between 9 November 2020 and 28 January 2021 and follow-up to 31 July 2021. Clients attending the supervised injecting facility were offered HCV RNA testing using the Xpert® HCV Viral Load Fingerstick (Cepheid, Sunnyvale, CA) PoCT. Participants with a positive HCV RNA test were prescribed direct acting antiviral (DAA) therapy. The primary endpoint was the proportion of clients who engaged in HCV RNA PoCT, compared to a historical comparator group when venepuncture-based hepatitis C testing was standard of care. RESULTS: Among 1618 clients who attended the supervised injecting facility during the study period, 228 (14%) engaged in PoCT. This was significantly higher than that observed in the historical comparator group (61/1,775, 3%; p < 0.001). Sixty-five (28%) participants were HCV RNA positive, with 40/65 (62%) receiving their result on the same day as testing. Sixty-one (94%) HCV RNA positive participants were commenced on DAA therapy; 14/61 (23%) started treatment on the same day as diagnosis. There was no difference in the proportion of HCV RNA positive participants commenced on treatment with DAA therapy when compared to the historical comparator group (61/65, 94% vs 22/26, 85%; p = 0.153). However, the median time to treatment initiation was significantly shorter in the PoCT cohort (2 days (IQR 1-20) vs 41 days (IQR 22-76), p < 0.001). Among participants who commenced treatment and had complete follow-up data available, 27/36 (75%) achieved hepatitis C cure. CONCLUSIONS: HCV RNA PoCT led to a significantly higher proportion of clients attending a supervised injecting facility engaging in hepatitis C testing, whilst also reducing the time to treatment initiation.

New and Delayed Artifactual Hypoglycemia Following Septic Shock in Two Scleroderma Patients.

The term artifactual hypoglycemia refers to a discrepancy between plasma glucose levels and what is noted on fingerstick glucose checks. In this report, we discuss the cases of two patients with scleroderma and Raynaud's phenomenon who developed artifactual hypoglycemia while recovering from critical illness. In both cases, validation by earlobe measurements helped avoid further escalation of care and potential patient safety issues. There have been previous reports of artifactual hypoglycemia in this patient population, but the unique timing of symptom onset in these two patients provides a more nuanced understanding of the pathophysiology of this phenomenon.

Application of glycemic qualification rate based on fingerstick glucose monitoring in women with gestational diabetes mellitus.

OBJECTIVE: To explore the appropriate application of glycemic qualification rate (GQR) calculated by fingerstick blood glucose (BG) monitoring for patients with gestational diabetes mellitus (GDM) by analyzing the relationship between BG control and adverse pregnancy outcomes. METHODS: Fingerstick Blood Glucose data during the second and third trimester of singleton pregnant women diagnosed with GDM were collected. GQR which is defined as the percentage of fingerstick BG values reaching the targets of BG control in a period of time was calculated. Patients were divided into three groups according to tertiles (tertile 1, GQR <56.25%; tertile 2, GQR 56.25-75%; and tertile 3, GQR ≥75%). Pregnant outcomes were compared among the three groups. Univariate analysis and logistic regression were performed to analyze the potential relationship between GQR and pregnancy outcomes. Receiver operating characteristic (ROC) curves were calculated to determine the cutoff values. We also explored that whether twice or three times monitoring per day would be adequate for GQR calculation, so we brought in two or three glucose measuring times per day to explore the relationship between new GQR and adverse outcomes. RESULTS: A total of 311 patients diagnosed with GDM were analyzed. In univariate analysis, the incidences of cesarean section of tertile 1-3 groups were 61.4%, 58.7%, and 44.9%, respectively (p < .05). The incidences of neonatal hypoglycemia of tertiles 1-3 groups were 19.8%, 18.6%, and 8.7% (p < .05). The difference of composite outcomes was statistically significant (p = .001). After adjustment, the patients with worse BG control (lower GQR) had higher risk of cesarean section (tertile 1 - aOR = 2.029, 1.128-3.648), neonatal hypoglycemia (tertile 1: aOR = 2.498, 1.082-5.766) as well as composite outcomes. The ROC curve of GQR indicated the predictive value for neonatal hypoglycemia (area under the ROC curve (AUC) 0.612 (0.532-0.692)) and neonatal composite outcomes (AUC 0.593 (0.528-0.657)) with optimal cutoff values of 81.1% and 73.5%, respectively. We also explored that whether twice or three times monitoring per day would be adequate for GQR calculation. The result showed that GQR only calculated by FBG + 2hPG after lunch (2h AL) per day also had well relationship with cesarean section (tertile 1: OR = 2.412, 1.322-4.398), neonatal hypoglycemia (tertile 1: aOR = 4.497, 1.607-12.586), and neonatal composite outcomes (tertile 1: aOR = 1.959, 95% confidence interval (CI): 1.114-3.444, p = .020). CONCLUSIONS: The GQR calculated by the easily applicable fingerstick BG is related to occurrence of cesarean section and neonatal hypoglycemia in GDM women. GQR ≥ 80% is recommended for better pregnancy outcomes. As for the number of points monitoring per day, GQR calculated by FBG + 2h AL was an optimal option for better pregnancy outcomes if mothers needed to simplify the process of monitoring.

Assessment of the Cepheid 3-gene Host Response Fingerstick Blood Test (MTB-HR) on rapid diagnosis of tuberculosis.

ABSTRACTThe World Health Organization has identified high-priority target product profiles for new TB diagnostics which include rapid biomarker-based, non-sputum-based diagnostic testing, using an easily accessible sample. The Cepheid 3-gene Host Response Fingerstick Blood Prototype Test (MTB-HR) quantifies relative mRNA levels of a 3-gene signature (GBP5, DUSP3, and KLF2) from a whole-blood sample on the GeneXpert platform. The objective of the present study was to evaluate the performance of the MTB-HR to distinguish between active tuberculosis (ATB), latent Mycobacterium tuberculosis infection (LTBI), other pulmonary diseases, and healthy volunteers at a tertiary care centre. Among 653 participants enrolled in this study, 192 were diagnosed as having ATB, and the remaining 461 were classified as non-ATB, including 137 cases of LTBI, 224 cases of other pulmonary diseases, and 100 healthy volunteers. The corresponding AUCs of the MTB-HR in distinguishing untreated ATB from non-ATB, LTBI, other pulmonary diseases, and healthy volunteers were 0.814 (95% CI, 0.760-0.868, sensitivity 76.1%, specificity 71.6%), 0.739 (95% CI, 0.667-0.812, sensitivity 59.7%, specificity 78.1%), 0.825 (95% CI, 0.770-0.880, sensitivity 82.1%, specificity 65.6%), 0.892 (95% CI, 0.839-0.945, sensitivity 76.1%, specificity 88.0%), respectively. When only samples with TAT of less than 1 h were included, the AUC of the MTB-HR in distinguishing untreated ATB from non-ATB was largest, 0.920 (95% CI, 0.822-1.000, sensitivity 81.3%, specificity 87.7%). In conclusion, the MTB-HR assay shows potential as a rapid, blood-based screening and triage test for ATB, especially for untreated ATB, with the advantage of increased diagnostic yield since blood is more readily available.

Fingerstick glucose monitoring by cognitive impairment status in Veterans Affairs nursing home residents with diabetes.

BACKGROUND: Guidelines recommend nursing home (NH) residents with cognitive impairment receive less intensive glycemic treatment and less frequent fingerstick monitoring. Our objective was to determine whether current practice aligns with guideline recommendations by examining fingerstick frequency in Veterans Affairs (VA) NH residents with diabetes across cognitive impairment levels. METHODS: We identified VA NH residents with diabetes aged ≥65 residing in VA NHs for >30 days between 2016 and 2019. Residents were grouped by cognitive impairment status based on the Cognitive Function Scale: cognitively intact, mild impairment, moderate impairment, and severe impairment. We also categorized residents into mutually exclusive glucose-lowering medication (GLM) categories: (1) no GLMs, (2) metformin only, (3) sulfonylureas/other GLMs (+/- metformin but no insulin), (4) long-acting insulin (+/- oral/other GLMs but no short-acting insulin), and (5) any short-acting insulin. Our outcome was mean daily fingersticks on day 31 of NH admission. RESULTS: Among 13,637 NH residents, mean age was 75 years and mean hemoglobin A1c was 7.0%. The percentage of NH residents on short-acting insulin varied by cognitive status from 22.7% in residents with severe cognitive impairment to 33.9% in residents who were cognitively intact. Mean daily fingersticks overall on day 31 was 1.50 (standard deviation = 1.73). There was a greater range in mean fingersticks across GLM categories compared to cognitive status. Fingersticks ranged widely across GLM categories from 0.39 per day (no GLMs) to 3.08 (short-acting insulin), while fingersticks ranged slightly across levels of cognitive impairment from 1.11 (severe cognitive impairment) to 1.59 (cognitively intact). CONCLUSION: NH residents receive frequent fingersticks regardless of level of cognitive impairment, suggesting that cognitive status is a minor consideration in monitoring decisions. Future studies should determine whether decreasing fingersticks in NH residents with moderate/severe cognitive impairment can reduce burdens without compromising safety.

A new testing platform using fingerstick blood for quantitative antibody response evaluation after SARS-CoV-2 vaccination.

Testing and vaccination have been major components of the strategy for combating the ongoing COVID-19 pandemic. In this study, we have developed a quantitative anti-SARS-CoV-2 spike (S1) IgG antibody assay using a fingerstick dried blood sample. We evaluated the feasibility of using this high-throughput and quantitative anti-SARS-CoV-2 spike (S1) IgG antibody testing assay in vaccinated individuals. Fingerstick blood samples were collected and analyzed from 137 volunteers before and after receiving the Moderna or Pfizer mRNA vaccine. Anti-SARS-CoV-2 S1 IgG antibody could not be detected within the first 7 days after receiving the first vaccine dose, however, the assay reliably detected antibodies from day 14 onwards. In addition, no anti-SARS-CoV-2 nucleocapsid (N) protein IgG antibody was detected in any of the vaccinated or healthy participants, indicating that the anti-SARS-CoV-2 S1 IgG assay is specific for the mRNA vaccine-induced antibodies. The S1 IgG levels detected in fingerstick samples correlated with the levels found in venous blood plasma samples and with the efficacy of venous blood plasma samples in the plaque reduction neutralization test (PRNT). The assay displayed a limit of quantification (LOQ) of 0.59 µg/mL and was found to be linear in the range of 0.51-1000 µg/mL. Finally, its clinical performance displayed a Positive Percent Agreement (PPA) of 100% (95% CI: 0.89-1.00) and a Negative Percent Agreement (NPA) of 100% (95% CI: 0.93-1.00). In summary, the assay described here represents a sensitive, precise, accurate, and simple method for the quantitative detection and monitoring of post-vaccination anti-SARS-CoV-2 spike IgG responses.

A Novel Dry-Stabilized Whole Blood Microsampling and Protein Extraction Method for Testing of SARS-CoV-2 Antibody Titers.

The COVID-19 pandemic has revealed a crucial need for rapid, straightforward collection and testing of biological samples. Serological antibody assays can analyze patient blood samples to confirm immune response following mRNA vaccine administration or to verify past exposure to the SARS-CoV-2 virus. While blood tests provide vital information for clinical analysis and epidemiology, sample collection is not trivial; this process requires a visit to the doctor's office, a professionally trained phlebotomist to draw several milliliters of blood, processing to yield plasma or serum, and necessitates appropriate cold chain storage to preserve the specimen. A novel whole blood collection kit (truCOLLECT) allows for a lancet-based, decentralized capillary blood collection of metered low volumes and eliminates the need for refrigerated transport and storage through the process of active desiccation. Anti-SARS-CoV-2 spike (total and neutralizing) and nucleocapsid protein antibody titers in plasma samples obtained via venipuncture were compared to antibodies extracted from desiccated whole blood using Adaptive Focused Acoustics (AFA). Paired plasma versus desiccated blood extracts yields Pearson correlation coefficients of 0.98; 95% CI [0.96, 0.99] for anti-SARS-CoV-2 spike protein antibodies, 0.97; 95% CI [0.95, 0.99] for neutralizing antibodies, and 0.97; 95% CI [0.94, 0.99] for anti-SARS-CoV-2 nucleocapsid protein antibodies. These data suggest that serology testing using desiccated and stabilized whole blood samples can be a convenient and cost-effective alternative to phlebotomy.

Fingerstick Glucose Monitoring in Veterans Affairs Nursing Home Residents with Diabetes Mellitus.

BACKGROUND/OBJECTIVE: Guidelines recommend less intensive glycemic treatment and less frequent glucose monitoring for nursing home (NH) residents. However, little is known about the frequency of fingerstick (FS) glucose monitoring in this population. Our objective was to examine the frequency of FS glucose monitoring in Veterans Affairs (VA) NH residents with diabetes mellitus, type II (T2DM). DESIGN AND SETTING: National retrospective cohort study in 140 VA NHs. PARTICIPANTS: NH residents with T2DM and older than 65 years admitted to VA NHs between 2013 and 2015 following discharge from a VA hospital. MEASUREMENTS: NH residents were classified into five groups based on their highest hypoglycemia risk glucose-lowering medication (GLM) each day: no GLMs; metformin only; sulfonylureas; long-acting insulin; and any short-acting insulin. Our outcome was a daily count of FS measurements. RESULTS: Among 17,474 VA NH residents, mean age was 76 (standard deviation (SD) = 8) years and mean hemoglobin A1c was 7.6% (SD = 1.5%). On day 1 after NH admission, 49% of NH residents were on short-acting insulin, decreasing slightly to 43% at day 90. Overall, NH residents had an average of 1.9 (95% confidence interval (CI) = 1.8-1.9) FS measurements on NH day 1, decreasing to 1.4 (95% CI = 1.3-1.4) by day 90. NH residents on short-acting insulin had the most frequent FS measurements, with 3.0 measurements (95% CI = 2.9-3.0) on day 1, decreasing to 2.6 measurements (95% CI = 2.5-2.7) by day 90. Less frequent FS measurements were seen for NH residents receiving long-acting insulin (2.1 (95% CI = 2.0-2.2) on day 1) and sulfonylureas (1.7 (95% CI = 1.5-1.8) on day 1). Even NH residents on metformin monotherapy had 1.1 (95% CI = 1.1-1.2) measurements on day 1, decreasing to 0.5 (95% CI = 0.4-0.6) measurements on day 90. CONCLUSION: Although guidelines recommend less frequent glucose monitoring for NH residents, we found that many VA NH residents receive frequent FS monitoring. Given the uncertain benefits and potential for substantial patient burdens and harms, our results suggest decreasing FS monitoring may be warranted for many low hypoglycemia risk NH residents.

Mycophenolate Mofetil and Plasmapheresis: A Treatment Option for Severe Insulin Resistance caused by Insulin Antibodies.

OBJECTIVE: Insulin antibody (IA)-mediated insulin resistance (IR) is a rare condition for which immunosuppressive regimens have been described. However, these raise the risk of infection, and the drugs may not be effectively metabolized in patients with liver disease. A 61-year old male with type 2 diabetes mellitus and antibody-mediated IR who required >800 units of daily insulin presented with acute decompensation of his preexisting cirrhosis from recurrent diabetic ketoacidosis. Laboratory tests confirmed an IA level of >625 µU/mL (reference: <5.0 µU/mL). METHODS: Centrifugal plasmapheresis and mycophenolate mofetil (MMF) were used to treat the patient to achieve glycemic control. Continuous glucose monitoring was implemented to monitor glycemic control pre- and posttherapy. Laboratory evaluation included levels of IA, C-peptide, insulin-like growth factor-1, growth hormone, salivary cortisol, zinc transporter 8, glutamic acid decarboxylase 65-kilodalton isoform antibody, and islet-cell antibodies. RESULTS: We initiated MMF followed by 5 sessions of plasmapheresis, leading to an overall 77.3% reduction from pretherapy insulin requirements after 6 months without further episodes of diabetic ketoacidosis or infection. The cirrhosis stabilized, and there was an improvement in HbA1C from 8.7% (72 mmol/mol) to 6.6% (49 mmol/mol) and time in euglycemic range from 30% to 61%. CONCLUSION: This is the first report of MMF and centrifugal plasmapheresis use to mitigate the effects of IA-mediated IR in a patient with cirrhosis. We recommend further studies to determine the utility of this treatment to improve care for patients at high risk for IA-mediated IR.

Development and validation of a simple and rapid way to generate low volume of plasma to be used in point-of-care HIV virus load technologies.

A new point-of-care HIV viral load, mPIMA HIV-1/2 VL, Abbott, USA, has been recently developed. This point-of-care viral load requires no skilled person to run and uses a small plasma volume (50µL). However, obtaining 50µL of plasma can be a challenge in limited resource settings. We validated a simple and easy method to obtain enough amount of plasma to run a point-of-care viral load. The study utilized 149 specimens from patients failing antiretroviral therapy. At least 250µL of whole blood was collected in a microtube/EDTA from fingerstick (fs-plasma) and immediately centrifuged. Parallel collection of venous blood to obtain plasma (vp-plasma) was used to compare performance in a point-of-care viral load assay and in methodology used in centralized laboratories Abbott M2000, Abbott, USA. The procedure for plasma collection takes less than 10min and in 94% of the cases only one fingerstick was sufficient to collect at least 250µL of blood. The Pearson correlation coefficient value for vp-plasma versus fs-plasma ran on mPIMA was 0.990. The Bland-Altman mean difference (md) for this comparison were virtually zero (md=-0.001) with limits of agreement between -0.225 and 0.223. In addition, the Pearson correlation coefficient value for fs-plasma in mPIMA versus vp-plasma in Abbott M2000 was 0.948 for values above the mPIMA limit of quantification (LoQ; from 800 to 1,000,000copies/mL). These results validate this simple plasma isolation method capable to be implemented in low resource countries where point-of-care decentralization is deeply needed.

Claros System: A Rapid Microfluidics-Based Point-of-Care System for Quantitative Prostate Specific Antigen Analysis from Finger-Stick Blood.

INTRODUCTION: Determination of circulating prostate specific antigen (PSA) is commonly used in the diagnosis and treatment monitoring of prostate cancer [1]. Presently, PSA testing is performed in centralized laboratories, which is associated with prolonged time between venipuncture and the PSA value being available. In this prospective study, we present a new and rapid test system for the quantitative determination of PSA levels from finger-stick blood. METHODS: The Claros1® analyzer is a rapid microfluidics-based point-of-care system for quantitative PSA analysis from 10-µl finger-stick blood that requires only 10 min for testing. Total PSA concentrations by the Claros system in 100 consecutive asymptomatic men (median age 57 years, range 44-81 years) were compared with two commercially available, commonly used PSA assays (Abbott and Elecsys by Roche) performed by a reference laboratory. RESULTS: Eighty-six percent of finger-stick blood-borne probes from 100 men were evaluable for PSA testing by the Claros1® analyzer system. In 13/14 cases the expiry date of the microfluid cassettes of the Claros system was exceeded and one blood puncture was performed inadequately. The correlations between the Claros results and OPKO-Abbott and OPKO-Roche assay results were high, with R2 values of 0.982 and 0.985, respectively. The R2 value for the Roche-Abbott correlation was 0.991 with a slope value of 1.160. Prostate cancer was diagnosed in seven cases, with a median PSA of 1.8 ng/ml in the Claros group compared to 1.75 ng/ml and 2.1 ng/ml in the Abbott and Roche groups, respectively. CONCLUSION: The Claros1® PSA assay combines the advantages of rapid, accurate detection with a low required sample volume, allowing the analysis to be performed using finger-stick blood. Provided that further analysis proves the reproducibility of the test, it may help to reduce the number of office visits, thus decreasing costs to the health care system.

Use of a capillary specimen in the laboratory to verify a point-of-care international normalized ratio: Avoidance of a venipuncture in a pediatric setting.

INTRODUCTION: Point-of-care (POC) international normalized ratio (INR) values above an institutional cutoff are confirmed in the laboratory using a gold standard venous specimen. This can be problematic in a pediatric setting. METHOD: In this study, 449 consecutive POC INR results were compared to an INR performed in the laboratory on a capillary citrate specimen collected from the same finger-stick. The results were statistically analyzed. RESULTS: The mean INR values from the CoaguChek XS and laboratory were 2.85 ± 1.19 and 2.63 ± 1.11, respectively. There was a good correlation between the methods with r = 0.97. Bland-Altman analysis indicated a bias of 0.22 favoring the CoaguChek XS, with 95% limits of agreement -0.29 to 0.72. Passing and Bablok method comparison resulted in a slope of 0.91 (y = 0.91x + 0.02). An INR of ≤0.5 was found between the methods in 89% of cases and 84% agreement was noted (κ = 0.69). CONCLUSION: Comparing the capillary INR laboratory results to studies involving a venous specimen, the capillary specimen performed with equivalence. Thus, a capillary citrate specimen can be collected from the same finger-stick used to perform the POC INR for confirmation in the laboratory. This avoids the trauma of a venous collection in such a situation.

Continuous Glucose Monitoring: Review of an Innovation in Diabetes Management.

Most continuous glucose monitors (CGM) provide interstitial fluid glucose trends, which reflect blood glucose trends with alarms and alerts to prevent hypoglycemia and provide better glycemic control. CGM used in conjunction with insulin pumps has changed the management of patients with insulin-dependent diabetes, mainly type 1 diabetes. CGM technology prevents the need for frequent blood glucose testing, which is often cumbersome for patients, providing them with a better alternative. CGM technology is underprescribed and therefore advantage should be taken of this technology to provide better hemoglobin A1c (HbA1c) control and decrease incidence of diabetic complications. CGM is particularly useful in patients with hypoglycemia unawareness and nocturnal hypoglycemia. CGM is currently not approved in pregnant patients, in critically ill patients and patients on dialysis. Research suggests that the benefits certainly outweigh the limitations of this technology. This review article focuses on the technical and clinical use of continuous glucose monitoring and sensor-integrated pump technology.