Anti-B2M monoclonal antibody, clone YTH470.5

Introduction: Chronic kidney disease of uncertain etiology (CKDu), an emerging chronic kidney disease (CKD) subtype, contributes to significant morbidity and mortality in certain tropical countries. Although several indicators of CKDu have been previously suggested, sensitive and specific tests to detect early disease or predict disease progression are currently unavailable. This study focused on evaluating 8 renal urinary markers, namely neutrophil gelatinase-associated lipocalin (NGAL), Kidney Injury Molecule-1 (KIM1), cystatin C (CST3), beta 2 microglobulin (B2M), osteopontin (OPN), alpha 1 microglobulin (A1M), tissue inhibitor of metalloproteinase 1 (TIMP1), and retinol binding protein 4 (RBP4), with the hypothesis that these have distinct expression patterns in patients with CKDu. Methods: A cross-sectional study was conducted with 5 study groups comprising subjects from CKDu, endemic CKD, nonendemic CKD, and endemic healthy and nonendemic healthy controls. The urinary levels of the 8 selected renal biomarkers were quantified using multiplex biomarker assay, and the data were subjected to systematic analysis using logistic regression algorithm aiming to extract the best marker combination that could distinctly identify the disease groups noninvasively from the healthy controls. Results: A 3-marker signature panel comprising A1M, KIM1, and RBP4 was identified to represent the best minimum marker combination for differentiating all CKD categories, including CKDu, from healthy controls with an overall sensitivity of >= 0.867 and specificity >= 0.765. The marker combination comprising OPN, KIM1, and RBP4 showed high predictive performance for distinguishing patients with CKDu from patients with CKD with both sensitivity and specificity >= 0.93, which was superior to any existing noninvasive indicator. Conclusion: In all, our systematic evaluation of urinary markers previously linked to CKD, in general, allowed identification of exclusive marker panel combination for early diagnosis and confirmation of CKDu.

Tendon cells (TCs) are important for homeostatic maintenance in the healthy tendon and to promote tissue healing after injury. Further, resident and rare populations of tendon stem/progenitor cells, located at various sites within the tendon, contribute to tendon recovery by differentiating into repairing TCs. Gene expression analysis, through quantitative reverse-transcription polymerase chain reaction (qRT-PCR), constitutes a useful tool to study cellular responses, including the transition from initial inflammation to healing processes. A critical step required for data normalization is the choice of reliable reference genes (RGs), a process highly underestimated in tendon biology. In this study, the suitability of five commonly used RGs (ACTB, B2M, GAPDH, HPRT1, and RPLP0) was evaluated using TCs samples cultured in both standard and progenitor-enriching conditions, as well as under either inflammatory (IFN gamma + TNF alpha) or pro-fibrotic/healing (CTGF) stimulation. The stability of the candidate RGs was computationally determined using NormFinder, geNorm, BestKeeper, and DeltaCt applets. Overall, ACTB resulted as the most stable RG on the basis of the integration of each gene weight, whereas B2M and RPLP0 performed poorly. To further validate ACTB's optimal performance, we evaluated the expression of ICAM1, coding for an immune-related cell surface glycoprotein, and COL1A1, encoding collagen type I that is the main component of the tendon extracellular matrix (ECM), both known to be modulated by inflammation. The expression of both genes was heavily affected by the RGs used. Consequently, when analyzing gene expression in tendon-derived cells subjected to various stimulatory protocols, the use of a suitable RG should be considered carefully. On the basis of our results, ACTB can be reliably used when analyzing different TC types exposed to pathological conditions.