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AIMS:The aim of this study was to investigate the association between haptoglobin (Hp) phenotypes and risk of the development of diabetic retinopathy (DR) in patients of type 2 diabetes mellitus.MATERIALS AND METHODS:This cross-sectional study included 45 normotensive type 2 diabetic patients (duration more than 5 years) admitted in the hospital divided into two groups (with and without DR) on the basis of fundus examination by direct ophthalmoscopy. Serum samples of all patients were subjected for Hp phenotyping by polyacrylamide gel electrophoresis.RESULTS:DR was associated significantly in diabetic patients with Hp2-2 phenotype (79.31%) than diabetic patients with Hp2-1 phenotype (43.75%) and Hp2-2 had higher odds ratio (OR) for DR in univariate analysis (OR 4.929, [95% confidence interval [CI] (1.297-18.733)], P = 0.016) and multivariate analysis (OR 7.704 [95% CI (0.887-66.945)], P = 0.064). Furthermore, Hp2-2 was associated significantly with severe forms of DR.CONCLUSION:Hp2-2 phenotype is associated with susceptibility to DR showing a graded risk relationship to the number of Hp2 alleles. Determination of Hp phenotype may be useful in the risk assessment and management of DR.

AIMS AND OBJECTIVES:The present study was evaluated the atheroprotective potential of paraoxonase1 (PON1) and its Q192R polymorphism, to determine whether this polymorphism, which is responsible for differential PON1 activity plays any role in the pathogenesis, severity and extent of coronary artery disease (CAD).MATERIALS AND METHODS:This hospital-based cross-sectional study investigated 60 diagnosed cases of CAD and 60 age and gender matched controls. All were assessed for serum PON1 activity, PON1 Q192R polymorphism and for classical cardiovascular risk factors. Individual serum phenotyping for PON1 Q192R polymorphism was determined by double substrate hydrolysis assay. Severity of CAD was assessed by the length of intensive cardiac care unit (ICCU) stay.RESULTS:Serum PON1 activity is significantly reduced in cases of CAD (92.6 ± 31.13 IU/L when compared with controls (105.26 ± 32.53 IU/L). Furthermore, serum arylesterase activity is reduced in CAD patients (90.31 ± 23.26 kU) when compared with the control subjects (101.61 ± 28.68 kU). Serum PON1 and arylesterase activities are significantly negatively correlated with the length of ICCU stay (r = −393 and r = −374 respectively). There is no significant difference in the occurrence of CAD and length of ICCU stay among the PON1 phenotypes (P = 0.92). Logistic regression analysis after adjustment of established risk factors revealed no significant association between CAD risk and PON1 Q192R polymorphism (odds ratios: 1.179 [95% confidence intervals: 0.507-2.744], P = 0.702).SUMMARY AND CONCLUSIONS:The current study demonstrates that the activity of the PON1 enzyme may be more important factor than the PON1 Q192R polymorphism in the severity and extent of CAD.

Background & objectives:The present study evaluated usefulness of cation exchange highperformance liquid chromatography (HPLC) as a screening tool for early detection of thalassemia & hemoglobin variants in dried blood spot (DBS) samples. We discussed the laboratory aspects ofdiagnostic difficulties in HPLC based screening algorithm in Indian population.Methods:-A total of 32000 DBS samples collected from neonates were primarily screened for hemoglobinopathies on HPLC between June 2013 and May 2016. All presumptive abnormal profiles were re-tested on HPLC after 6 months of age. The follow up results were correlated with parental studies and additional investigations for confirmation.Results: Totally 982 samples (3.06%) showed abnormal HPLC pattern on primary neonatal screening. In follow up testing of 914 presumptive abnormal cases, 583 (1.82%) cases have been confirmed for variant hemoglobin's. Sickle variant was the commonest hemoglobinopathy found in 156 (26.7%) cases. HbE (21.4%), β-thalassemia (19.5%) and HbD (19.5%) disorders being the next common variants. HPLC alone diagnosed more than 85% cases with abnormal variants. Interpretation &Conclusions: Analysis of DBS samples on HPLC is a convenient primary tool for hemoglobin variant screening for hemoglobinopathies. Our study enabled us to design a practical flow chart for large scale HPLC based screening of major hemoglobinopathies with judicious requirement of investigations on other platforms.

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Background:The present study aims at two tier analysis for diagnosis and confirmation of organic acidemia using simultaneous analysis of dried blood spot (DBS) carnitine profile by tandem mass spectrometry (TMS) and urine metabolic analysis on gas chromatography mass spectrometry (GC/MS). Material and Methods: This cross sectional study included 348 DBS samples and their dried filter paper urine sample came for routine and emergency screening of inborn errors of metabolism (IEM). All DBS samples were anlysed for amino acid and acylcarnitine profile derivatized on TMS. All these cases were simultaneously tested for urine organic acid pattern on GC/MS which involved urease pretreatment, deproteinisation followed by derivatisation. Confirmation of IEM was based on the two tier approach containing the blood and urine metabolic pattern as recommended by panel of American College of Medical Genetics (ACMG). Results: 17 cases were screened positive for IEM analysed separately for amino acid /acylcarnitine profile and urine organic acid profile. However the two tier testing screened and confirmed 8 cases of organic academia within 36 hours of receipt of sample which included 2 cases each of maple syrup urine disease (MSUD), glutaric acidemia Type I (GA I), and β-ketothiolase deficiency (BKT) and one each case of multiple carboxylase deficiency (MCD) and propionic acidemia (PA). Conclusion: The simultaneous two tier metabolome testing for screening of IEM is more comprehensive, cost effective, delivering confirmatory results with significantly reduced turnaround time, thus reducing recall rate by eliminating false-positive results and help prevent unnecessary anxiety of parents.

Congenital adrenal hyperplasia (CAH), screened for in neonates, is the second most common endocrinopathy after congenital hypothyroidism.Newborn screening for CAH due to CYP21A2 deficiency is performed by immunologic assay for 17-hydroxyprogesterone (17-OHP). The second-tier test for confirmation of diagnosis is carried out on recall venous blood sample from screen positives measuring 17-OHP, or other metabolites of steroid metabolism by liquid chromatography–tandem mass spectroscopy. However, as steroid metabolism is dynamic, it can affect these parameters even in the recall sample of a stressed neonate. Moreover, there is some time delay in recalling the neonate for repeat testing. Reflex genetic analysis of blood spot from the initial Guthrie cards of screen positive neonates, if used for confirmatory testing, can avoid this time delay as well as the effect of stress on steroid metabolism. In this study, we used Sanger sequencing and MLPA in a reflex manner for molecular genetic analysis to confirm CYP21A2-mediated CAH. Out of 220,000 newborns screened, 97 were positive on the initial biochemical screen, of which 54 were confirmed true positives with genetic reflex testing, giving incidence of CAH as 1:4074. Point mutations were more common than deletions, indicating that Sanger sequencing should be used ahead of MLPA for molecular diagnosis in India. Amongst the variants detected, the most common was I2G-Splice variant (44.5%), followed by c.955C>T (p.Gln319Ter) (21.2%); Del 8 bp and c.-113G>A were detected with frequencies of 20.3% and 20%, respectively. In conclusion, reflex genetic testing is an effective strategy for identifying true positives in CAH screening in neonates. This will obviate need for recall samples and also aid effective counselling and timely prenatal diagnosis in the future. In Indian newborns, as point mutations are more common than large deletions, Sanger sequencing should be the initial method of choice for genotyping, ahead of MLPA.