Multicentric evaluation of a novel point of care electrochemical ELISA platform for SARS-CoV-2 specific IgG and IgM antibody assay.

New diagnostics technologies for the efficient detection and quantification of SARS-CoV-2 antibodies are very crucial to manage the COVID-19 pandemic, especially in the context of emerging vaccination paradigms. Herein, we report on a novel point-of-care Electrochemical ELISA platform with disposable screen printed electrodes functionalized with SARS-CoV-2 Spike Glycoprotein S1, to enable fast and accurate quantitative estimation of total antibody concentration (IgG and IgM) in clinical samples. The quantification is performed with a comparison of electrochemical redox current against the current produced by the spiked monoclonal antibodies with known concentration. The assay is validated through multicentric evaluation against 3 different FDA authorized Laboratory standard techniques, using both EDTA whole blood and serum samples. We demonstrate that the proposed assay has excellent sensitivity and specificity, making it a suitable candidate for epidemiological surveys and quantification of antibodies in COVID-19 vaccination programs.

Multicentric Evaluation of a Novel Point of Care Electrochemical ELISA Platform for SARS-CoV-2 Specific IgG and IgM Antibody Assay

New diagnostics technologies for the efficient detection and quantification of SARS-CoV-2 Antibodies is very crucial to manage the COVID-19 pandemic, especially in the context of emerging vaccination paradigms. Herein, we report on a novel point-of-care Electrochemical ELISA platform with disposable screen printed electrodes functionalized with SARS-CoV-2 Spike Glycoprotein S1, to enable fast and accurate quantitative estimation of total antibody concentration (IgG and IgM) in clinical samples. The quantification is performed with a comparison of electrochemical redox current against the current produced by the spiked monoclonal antibodies with known concentration. The assay is validated through multicentric evaluation against 3 different FDA authorized Laboratory standard techniques, using both EDTA whole blood and serum samples. We demonstrate that the proposed assay has excellent sensitivity and specificity, making it a suitable candidate for epidemiological surveys and quantification of antibodies in COVID-19 vaccination programs.

Factors associated with the onset of major depressive disorder in adults with type 2 diabetes living in 12 different countries: results from the INTERPRET-DD prospective study.

AIMS: To examine the factors that are associated with changes in depression in people with type 2 diabetes living in 12 different countries. METHODS: People with type 2 diabetes treated in out-patient settings aged 18-65 years underwent a psychiatric assessment to diagnose major depressive disorder (MDD) at baseline and follow-up. At both time points, participants completed the Patient Health Questionnaire (PHQ-9), the WHO five-item Well-being scale (WHO-5) and the Problem Areas in Diabetes (PAID) scale which measures diabetes-related distress. A composite stress score (CSS) (the occurrence of stressful life events and their reported degree of 'upset') between baseline and follow-up was calculated. Demographic data and medical record information were collected. Separate regression analyses were conducted with MDD and PHQ-9 scores as the dependent variables. RESULTS: In total, there were 7.4% (120) incident cases of MDD with 81.5% (1317) continuing to remain free of a diagnosis of MDD. Univariate analyses demonstrated that those with MDD were more likely to be female, less likely to be physically active, more likely to have diabetes complications at baseline and have higher CSS. Mean scores for the WHO-5, PAID and PHQ-9 were poorer in those with incident MDD compared with those who had never had a diagnosis of MDD. Regression analyses demonstrated that higher PHQ-9, lower WHO-5 scores and greater CSS were significant predictors of incident MDD. Significant predictors of PHQ-9 were baseline PHQ-9 score, WHO-5, PAID and CSS. CONCLUSION: This study demonstrates the importance of psychosocial factors in addition to physiological variables in the development of depressive symptoms and incident MDD in people with type 2 diabetes. Stressful life events, depressive symptoms and diabetes-related distress all play a significant role which has implications for practice. A more holistic approach to care, which recognises the interplay of these psychosocial factors, may help to mitigate their impact on diabetes self-management as well as MDD, thus early screening and treatment for symptoms is recommended.

Application of a Nanotechnology-Based, Point-of-Care Diagnostic Device in Diabetic Kidney Disease.

INTRODUCTION: Early detection of diabetes mellitus (DM) and diabetic kidney disease (DKD) is important for preventing end-stage renal failure and reducing cardiovascular complications. Availability of a validated point-of-care (PoC) device that can measure various DKD markers would be useful in this respect, especially in resource-poor parts of the world. METHODS: We validated a novel nanotechnology-based multianalyte PoC device (minimally invasive and does not require trained medical personnel) against laboratory gold standard tests for the detection of 5 biomarkers related to management of DM and DKD. The prospective study was funded by an International Society of Nephrology American Nephrologists of Indian Origin grant in 2 phases: (i) proof of concept: random samples were tested for the analytes with the PoC device and correlated with the laboratory gold standard; and (ii) clinical validation in a well-characterized cohort of patients. A nonenzymatic- and nonantibody-based electrochemical PoC device for quantitative measurement of markers-glycosylated hemoglobin (HbA1c), hemoglobin, serum albumin, microalbuminuria, urine creatinine, and albumin-to-creatinine ratio-was developed and used in this study. The disposable strips were interfaced with a multipotentiostat hand-held PoC device (3.7-V rechargeable lithium battery, 5-inch touch screen, Bluetooth enabled) working in amperometry mode, which provided the results in <1 minute. Data were analyzed using linearity plots and Bland-Altman difference plot analysis. RESULTS: A total of 4717 individuals were screened during the study (phase 1: 2576 and phase 2: 2141.) In phase 2, samples were tested in 529 subjects (346 females)-120 subjects with type 1 DM, 255 subjects with type 2 DM, 54 subjects without DM, 400 subjects with stage 2 chronic kidney disease, and 30 subjects with stage 3 chronic kidney disease. CONCLUSION: A nanotechnology-based PoC device for quantitative measurement of HbA1c, hemoglobin, serum albumin, microalbuminuria, and the urine albumin-to-creatinine ratio was developed for detection of early DKD and showed excellent correlation between the device and laboratory results. This device has the potential for early detection of DM and/or DKD, especially in remote communities in underserved areas of the world where prevalence of diabetes is rapidly increasing.

Prevalence and correlates of depressive disorders in people with Type 2 diabetes: results from the International Prevalence and Treatment of Diabetes and Depression (INTERPRET-DD) study, a collaborative study carried out in 14 countries.

AIMS: To assess the prevalence and management of depressive disorders in people with Type 2 diabetes in different countries. METHODS: People with diabetes aged 18-65 years and treated in outpatient settings were recruited in 14 countries and underwent a psychiatric interview. Participants completed the Patient Health Questionnaire and the Problem Areas in Diabetes scale. Demographic and medical record data were collected. RESULTS: A total of 2783 people with Type 2 diabetes (45.3% men, mean duration of diabetes 8.8 years) participated. Overall, 10.6% were diagnosed with current major depressive disorder and 17.0% reported moderate to severe levels of depressive symptomatology (Patient Health Questionnaire scores >9). Multivariable analyses showed that, after controlling for country, current major depressive disorder was significantly associated with gender (women) (P<0.0001), a lower level of education (P<0.05), doing less exercise (P<0.01), higher levels of diabetes distress (P<0.0001) and a previous diagnosis of major depressive disorder (P<0.0001). The proportion of those with either current major depressive disorder or moderate to severe levels of depressive symptomatology who had a diagnosis or any treatment for their depression recorded in their medical records was extremely low and non-existent in many countries (0-29.6%). CONCLUSIONS: Our international study, the largest of this type ever undertaken, shows that people with diabetes frequently have depressive disorders and also significant levels of depressive symptoms. Our findings indicate that the identification and appropriate care for psychological and psychiatric problems is not the norm and suggest a lack of the comprehensive approach to diabetes management that is needed to improve clinical outcomes.

Aza-heterocyclic Receptors for Direct Electron Transfer Hemoglobin Biosensor.

Direct Electron Transfer biosensors, facilitating direct communication between the biomolecule of interest and electrode surface, are preferable compared to enzymatic and mediator based sensors. Although hemoglobin (Hb) contains four redox active iron centres, direct detection is not possible due to inaccessibility of iron centres and formation of dimers, blocking electron transfer. Through the coordination of iron with aza-heterocyclic receptors - pyridine and imidazole - we report a cost effective, highly sensitive and simple electrochemical Hb sensor using cyclic voltammetry and chronoamperometry. The receptor can be either in the form of liquid micro-droplet mixed with blood or dry chemistry embedded in paper membrane on top of screen printed carbon electrodes. We demonstrate excellent linearity and robustness against interference using clinical samples. A truly point of care technology is demonstrated by integrating disposable test strips with handheld reader, enabling finger prick to result in less than a minute.

Management of anemia in patients with diabetic kidney disease: A consensus statement.

This consensus statement focuses on the window of opportunity, which exists while treating patients with diabetic kidney disease and anemia.

Type 1 diabetes pathogenesis - Prevention???

Pathogenesis of type 1 diabetes is multi-faceted, including, autoimmunity, genetics and environment. Autoimmunity directed against pancreatic islet cells results in slowly progressive selective beta-cell destruction ("Primary autoimmune insulitis"), culminating over years in clinically manifested insulin-dependent diabetes mellitus (IDDM). Circulating serum autoantibodies directed against the endocrine cells of the islets of Langerhans (Islet cell autoantibodies - ICAb) are an important hallmark of this disease. Assays for islet cell autoantibodies have facilitated the investigation and understanding of several facets in the pathogenesis of autoimmune diabetes. Their applications have extended into clinical practice and have opened new avenues for early preclinical prediction and preventive prophylaxis in IDDM/type 1 DM. Recently, surprisingly, differences in insulin content between T1DM islets, as well as, 'patchy' or 'lobular' destruction of islets have been described. These unique pathobiological phenomena, suggest that beta cell destruction may not always be inexorable and inevitably complete/total, and thus raise hopes for possible therapeutic interruption of beta cell autoimmunity - destruction and cure of type 1 diabetes. "Recurrent or secondary autoimmune insulitis" refers to the rapid reappearance of islet cell autoantibodies post pancreas transplant, and selective islet beta cell destruction in the grafted pancreas [never forgetting or "anamnestic" beta cell destructive memory], in the absence of any graft pancreas rejection [monozygotic twin to twin transplantation]. The one definite environmental factor is congenital rubella, because of which a subset of children subsequently develop type 1 diabetes. The putative predisposing factors are viruses, gluten and cow's milk. The putative protective factors include gut flora, helminths, viral infections, and Vitamin D. Prevention of T1DM can include: Primary prevention strategies before the development of autoantibodies and Secondary prevention regimens after autoantibody development. Once islet cell autoantibodies have developed, the goal is to establish a therapeutic regimen to preserve at least 90% of the beta cells, and prevent the development of hyperglycaemia. The targets for T1DM reversal should include autoimmunity, beta cell regeneration and protection of beta cell mass. Anti-CD3 teplizumab and anti-CD3 otelixizumab have been shown to provide C-peptide preservation. The unanswered questions in diabetes research include elimination of autoimmune memory responses, reestablishment of immune self-tolerance, and mechanisms of disease initiation.

Type 1 diabetes: Awareness, management and challenges: Current scenario in India.

Type 1 diabetes mellitus (T1DM) has a wide presence in children and has a high mortality rates. The disease, if left unmanaged, poses various challenges to the patient and healthcare providers, including development of diabetic complications and thus decreasing the life expectancy of the affected child. The challenges of T1DM include awareness of the disease that is very poor among the general public and also in parents of T1DM children along with the health care professionals. The challenge of lack of awareness of T1DM can be met by increasing public awareness programs, conducting workshops for diabetes educators regarding T1DM in children, newsletters, CMEs, online courses, and by structured teaching modules for diabetes educators. Diagnosis of T1DM was a challenge a few decades ago but the situation has improved today with diagnostic tests and facilities, made available even in villages. Investigation facilities and infrastructure, however, are very poor at the primary care level, especially in rural areas. Insulin availability, acceptability, and affordability are also major problems, compounded by the various types of insulin that are available in the market with a varied price range. But effective use of insulin remains a matter of utmost importance.

The INTERPRET-DD study of diabetes and depression: a protocol.

AIM: People with diabetes are at an increased risk of developing depression and other psychological disorders. However, little is known about the prevalence, correlates or care pathways in countries other than the UK and the USA. A new study, the International Prevalence and Treatment of Diabetes and Depression Study (INTERPRET-DD) aims to address this dearth of knowledge and identify optimal pathways to care across the globe. METHOD: INTERPRET-DD is a 2-year longitudinal study, taking place in 16 countries' diabetes outpatients' facilities, investigating the recognition and management of depressive disorders in people with Type 2 diabetes. Clinical interviews are used to diagnose depression, with clinical and other data obtained from medical records and through patient interviews. Pathways to care and the impact of treatment for previously unrecognized (undocumented) depression on clinical outcomes and emotional well-being are being investigated. RESULTS: Initial evidence indicates that a range of pathways to care exist, with few of them based on available recommendations for treatment. Pilot data indicates that the instruments we are using to measure both the symptoms and clinical diagnosis of depression are acceptable in our study population and easy to use. CONCLUSIONS: Our study will increase the understanding of the impact of comorbid diabetes and depression and identify the most appropriate (country-specific) pathways via which patients receive their care. It addresses an important public health problem and leads to recommendations for best practice relevant to the different participating centres with regard to the identification and treatment of people with comorbid diabetes and depression.

Feasibility of rapid parathormone assay for enabling minimally invasive parathyroid excision.

There is no doubt that the success of minimally invasive parathyroidectomy (MIP) has changed the whole treatment of patients with primary hyperparathyroidism, especially the approach towards traditional bilateral neck exploration. A single adenoma is the most common cause of primary hyperparathyroidism and its removal results in cure. Hence, it is worth the effort to localise and excise the single adenoma using modern technologies such as high-quality sestamibi scans and to confirm complete excision using rapid intra operative parathormone (IOPTH) assays. The objective of the study was to evaluate the feasibility of rapid IOPTH assay in successfully facilitating minimally invasive parathyroid excision. This research involved the retrospective study of seven patients, who underwent MIP at Sagar Hospital in Bengaluru, India, for parathyroid adenoma. All patients with evidence of unifocal disease on sestamibi scanning and cervical ultrasonography, underwent MIP via 2-3 cm lateral incision. Blood samples for measurement of IOPTH were taken at the time of induction of anaesthesia and 10 min after the adenoma excision. Reduction of parathormone (PTH) levels of more than 50 % in the postexcision sample was taken as evidence for complete extirpation of parathyroid adenoma. A solitary adenoma was identified in all the seven patients. After MIP, IOPTH levels fell in six of the seven patients. Following the surgery, all the cases were followed up for a period of 1 month. During this time, except for one patient, six patients remained asymptomatic and blood tests revealed normal serum calcium levels. A histopathological examination confirmed the diagnosis of parathyroid adenoma in six of the seven patients. After accurate preoperative localisation of the adenoma in patients with primary hyperparathyroidism, MIP with IOPTH measurement offers a safe and successful outcome.

Characterisation of a starch-hydrolysing enzyme of Aspergillus niger.

A UV-induced mutant strain of Aspergillus niger (CFTRI-1105-U9) overproduced a starch-hydrolysing enzyme with properties characteristically different from the known amylases of the fungus. The purified enzyme of 4.0 pI had an apparent molecular mass of 125 kDa and it dextrinised starch and then saccharified the dextrins. Patterns of the enzyme activity on starch, resulting in glucose at 60 degrees C and glucose, maltose and maltodextrins at 70 degrees C as primary products, suggested significant applications for the enzyme in starch-processing industries.

Prevalence & significance of pancreatic islet cell & adrenal antibodies in patients with Graves' disease.

The prevalence of adrenocortical (ACAb), islet cell (ICAb) and thyroid microsomal (TMAb) autoantibodies was determined by indirect immunofluorescence, in 88 consecutive patients with Graves' disease. ACAb, ICAb and TMAb positivity was seen in 3 (3.3%), 10 (11%) and 66 (75%) patients respectively. Among these one patient had both ACAb and ICAb positivity. Diabetes mellitus was found to be present in two (2.3%; both ICAb positive) of the 88 patients studied. Two of the four ICAb positive patients had loss of first phase insulin response to intravenous glucose. A significant proportion of patients of Graves' disease had associated islet cell and/or adrenal autoimmunity. A high index of suspicion for associated endocrine autoimmunity should be maintained while dealing with subjects of Graves' disease.

I-45 islet cell antigen is a 68kD neuroendocrine protein.

A monoclonal antibody approach was used to characterize islet cell differentiation antigens involved in autoimmunity related diabetes mellitus. This procedure yielded islet cell monoclonal antibodies (ICMAbs) that demonstrated varying tissue/cellular distribution. The ICMAb I-45 showed a pan-islet reactivity similar to the reactivity of islet cell autoantibodies. The target antigen of the ICMAb I-45 demonstrated a neuroendocrine distribution. Single step immunoaffinity purification of I-45 antigen using I-45 monoclonal antibody immunoaffinity matrix yielded a 68kD protein. The specificity of the immunoaffinity purified 68kD protein was further demonstrated by the lack of binding of this protein to immunoaffinity columns of irrelevant monoclonal antibodies. The neuroendocrine distribution of the I-45 antigen, like that of other differentiation molecules like HISL-19, neuron specific enolase and chromogranin A strengthens the hypothesis of neuroectodermal origin of the islets of Langerhans.

Chronic calcific pancreatitis of the tropics (CCPT): spectrum and correlates of exocrine and endocrine pancreatic dysfunction.

The exocrine and endocrine pathophysiology of chronic calcific pancreatitis of the tropics (CCPT) remains elusive. The objective of this study was to evaluate the spectrum and correlates of the exocrine and endocrine pancreatic dysfunction in CCPT. Thirty-seven consecutive patients with a clinico-radiological diagnosis of CCPT were stratified into three subgroups: CCPT-normal glucose tolerance (NGT), CCPT-abnormal glucose tolerance (IGT) and CCPT-diabetes mellitus (DM). Ten ketosis resistant young diabetic (KRDY) patients, 10 classical insulin dependent diabetes mellitus (IDDM) patients and 18 healthy matched controls were included for comparison. Fecal chymotrypsin (FCT) levels and blood C-peptide levels (basal and post i.v. glucagon stimulation) were estimated for assessing the exocrine and endocrine pancreatic functions, respectively. Sonography was performed to evaluate the pancreatic size and ductal diameter. Pancreatic exocrine-endocrine correlation was examined by studying the C-peptide/fecal chymotrypsin ratio (CP/FCT) (CP/FCT of normal controls = 1). Mean FCT levels in all 3 subgroups of CCPT (NGT: 3.4 micrograms/g; IGT: 0.82 microgram/g; DM: 2.4 micrograms/g) were very low (87-96% reduction in exocrine pancreatic dysfunction; mean FCT in healthy controls was 22.8 micrograms/g) (P < 0.0001). In contrast, KRDY and IDDM patients displayed 50-54% reduction in pancreatic acinar function (P < 0.001). Basal and stimulated C-peptide levels progressively fell in the 3 CCPT subsets (NGT: 0.23 and 0.46 > IGT: 0.14 and 0.29 > DM 0.10 and 0.14) (P < 0.01). CCPT patients exhibited pancreatic atrophy and ductal dilation (> 3 mm).(ABSTRACT TRUNCATED AT 250 WORDS)

Pancreatic islet transplantation: utility of ductular obstruction and exocrine atrophy model?

Introduction of 'silent' exocrine atrophy (and endocrine 'enrichment') in pancreatic grafts following ductular blockade may have a role in human diabetes by circumventing currently elusive islet isolation/purification protocols. To explore this potential, pancreatic isografts were performed in 12 pairs of inbred Wistar NIN rats. Donor pancreatectomy was performed after distal clamping and canulation of common bile duct and injection of 0.5 ml. polyacrylamide gel (blocked n = 7) or normal saline (un-blocked n = 5) respectively. One to 2 m.m. fragments of the resulting mildly distended pancreases were transplanted in to 2 sites (renal capsule and iliac fossa subcutaneously) of cach recipient. Post-operative biopsies of the transplanted grafts (unilateral nephrectomy and iliac fossa biopsies) revealed macroscopic and microscopic evidence of necrotizing pancreatitis in both the groups at both the sites (histiocytic and giant cell infiltration, fat necrosis and focal calcification with destruction of exocrine and endocrine cells) as early as 1 and 3 weeks. Possible detrimental factors include: volume and pressure of ductal injection, graft sites (confined spaces), post-operative wound infection and bio-compatibility of the material used for ductular blockade.

Heterogeneity of islet cell autoantibodies in terms of insulin release from rat islets and insulinoma cells.

The clinical significance of cytoplasmic islet cell autoantibodies (ICA) has been studied since their discovery by Bottazzo et al. in 1974. Some ICAs destroy pancreatic B cells in the presence of complement, whereas others take no part in this destruction. This suggests that islet function varies with the amount of ICA produced. In the present investigation we report the heterogeneity of monoclonal islet cell antibodies produced by one of us in terms of insulin release from isolated rat islets as well as from rat insulinoma cells (RINr).

Genetically programmed selective islet beta-cell loss in diabetic subjects with Wolfram's syndrome.

Insulin-producing beta-cells were selectively absent from the islets of Langerhans in postmortem specimens from two patients with Wolfram's syndrome. In families with multiple cases of this syndrome, we found a very high concordance rate (r = .910, P less than .001) among siblings for age at onset of diabetes mellitus. Taken together with the lack of markers for an autoimmune process, these findings suggest that diabetes mellitus in this syndrome results from genetically programmed selective beta-cell death.

Medullary thyroid carcinomas express chromogranin A and a novel neuroendocrine protein recognized by monoclonal antibody HISL-19.

PURPOSE AND METHODS: A number of endocrine peptides and proteins are expressed by medullary thyroid carcinoma (MTC). The expression of two newly appreciated neuroendocrine tumor markers, chromogranin A (CgA) and the endocrine antigen defined by monoclonal antibody HISL-19, was determined in 14 MTCs by immunohistology to evaluate the clinical utility of these markers in the diagnosis of MTC. Papillary, follicular, and undifferentiated thyroid tumors were also evaluated along with an MTC cell line. The same tissues were evaluated with antibodies to human calcitonin. RESULTS: All human calcitonin antibodies were found to react with the MTCs. In addition, all MTCs were reactive for CgA and the antigen detected by antibody HISL-19. CgA was generally present in the human calcitonin-containing cells, whereas the HISL-19 antigen had a more distinctive distribution. The other thyroid tumors failed to show reactivity with any of the three antibodies. CONCLUSION: Our results demonstrate that, in addition to human calcitonin, MTCs commonly express CgA and the antigen defined by antibody HISL-19. Our observations thus add to the repertoire of endocrine substances produced by MTC. These studies also demonstrate the clinical value of immunohistologic procedures for two novel antigens in distinguishing MTCs from other thyroid tumors.