Magic™ Anti-CALCA polyclonal antibody

Background: Serum calcitonin (sCT) is the main tumor marker for medullary thyroid cancer (MTC), but it has certain limitations. Various sCT assays may have important intra-assay or interassay variation and may yield different and sometimes conflicting results. A pentagastrin-or calcium-stimulation calcitonin (CT) test may be desirable in some situations. Alternatively, or in the absence of the stimulation test, mRNA detection offers the advantages of being more comfortable and less invasive; it only requires blood collection and has no side effects. The objective of this study was to investigate the applicability of measuring calcitonin-related polypeptide alpha (CALCA) gene transcripts (CT-CALCA and calcitonin gene-related peptide [CGRP]-CALCA) in patients with MTC and in relatives diagnosed with a RET mutation and to test mRNA as an alternative diagnostic tool for the calcitonin-stimulation test. Methods: Twenty-three healthy controls and 26 individuals evaluated for MTC were selected, including patients with sporadic or hereditary MTC and RET mutation-carrying relatives. For molecular analysis, RNA was extracted from peripheral blood, followed by cDNA synthesis using 3.5 mu g of total RNA. Quantitative real-time polymerase chain reaction (RT-qPCR) was performed with SYBR Green and 200nM of each primer for the two specific mRNA targets (CT-CALCA or CGRP-CALCA) and normalized with the ribosomal protein S8 as the reference gene. Results: We detected CALCA transcripts in the blood samples and observed a positive correlation between them (r = 0.946, p < 0.0001). Both mRNAs also correlated with sCT (CT-CALCA, r = 0.713, p < 0.0001; CGRP-CALCA, r = 0.714, p < 0.0001). The relative expression of CT-CALCA and CGRP-CALCA presented higher clinical sensitivity (86.67 and 100, respectively), specificity (97.06 and 97.06), positive predictive value (92.86 and 93.75), and negative predictive value (94.29 and 100), than did sCT (73.33, 82.35, 64.71, and 87.50, respectively). In addition, the CALCA transcript measurement mirrored the response to the pentagastrin test. Conclusion: We demonstrate that the measurement of CALCA gene transcripts in the bloodstream is feasible and may refine the management of patients with MTC and RET mutation-carrying relatives. We propose considering the application of this diagnostic tool as an alternative to the calcitonin-stimulation test.

Background Calcitonin gene-related peptide (CGRP) is the predominant neurotransmitter in capsaicin-sensitive sensory nerves. Participation of CGRP in hypertension is one of the most extensively studied topics in the field. There is growing evidence to the effect that CGRP is associated with essential hypertension (EH). The aims of this study were to pinpoint whether single nucleotide polymorphisms (SNPs) in the genes coding for CALCA were associated with EH susceptibility in a Hunan Han population. Methods A total of 293 subjects with EH and 208 controls were enrolled in the study. Genomic DNA was extracted from peripheral blood leucocytes by a phenol-chloroform method. The CALCA T-692C was genotyped using a restriction fragment length polymorphism method. Results A statistically significant difference in CALCA T-692C genotypic distribution was observed between cases and controls (P=0.001). Moreover, the frequencies of the C allele were 14.85% in the EH group and 7.45% in the control group, prevalence of C alleles in EH subjects and controls was significantly incomparable (P <0.001). Furthermore, the results of Logistic regression analysis showed that the carriers of C allele (TC+CC genotypes) were associated with increased EH risk (OR=2.093, 95% Cl: 1.317-3.326, P<0.01). Conclusions CALCA genetic polymorphism is associated with EH susceptibility. Carriers of at least one C allele at the polymorphic site CALCA T-692C showed increased risk for EH.