Is Afamin a novel biomarker for gestational diabetes mellitus? A pilot study

BACKGROUND

In search of potential early biomarkers for timely prediction of gestational diabetes mellitus (GDM), we focused on afamin, a vitamin E-binding protein in human plasma.. Afamin plays a role in anti-apoptotic cellular processes related to oxidative stress and is associated with insulin resistance and other features of metabolic syndrome. During uncomplicated pregnancy its serum concentrations increase linearly. The aim of this study was to investigate the suitability of afamin as early marker for predicting GDM.

METHODS

In a first-trimester cohort from a prospective observational study of adverse pregnancy outcomes we secondarily analyzed afamin concentrations in 59 patients diagnosed with GDM and 51 controls. Additionally, afamin concentrations were cross-sectionally examined in a mid-trimester cohort of 105 women and compared with results from a simultaneously performed oral glucose tolerance test (OGTT). Subgroup analysis comparing patients treated with either insulin (iGDM) or dietary intervention (dGDM) was performed in both cohorts. Patients were recruited at the University Hospital Essen, Germany, between 2003 and 2016.

RESULTS

Results were adjusted for body-mass-index (BMI) and gestational age. First and mid-trimester cohorts yielded significantly elevated afamin concentrations in patients with pathological OGTT compared to patients without GDM (first trimester cohort: mean, 113.4 mg/l; 95% CI, 106.4-120.5 mg/l and 87.2 mg/l; 95% CI, 79.7-94.7 mg/l; mid-trimester cohort: mean, 182.9 mg/l; 95% CI, 169.6-196.2 mg/l and 157.3 mg/l; 95% CI, 149.1-165.4 mg/l, respectively). In the first-trimester cohort, patients developing iGDM later in pregnancy presented with significantly higher afamin concentrations compared to patients developing dGDM and compared to patients without GDM. In the mid-trimester cohort, mean concentrations of afamin differed significantly between patients with dGDM compared to controls and between patients with iGDM and controls. Patients with iGDM showed only slightly higher afamin levels compared to patients with dGDM.

CONCLUSION

Afamin may serve as a new early biomarker for pathological glucose metabolism during pregnancy. Further research is needed to determine afamin's concentrations during pregnancy, its predictive value for early detection of pregnancies at high risk to develop GDM and its diagnostic role during the second trimester.

Significance of pre-transplant anti-HLA antibodies detected on an ELISA mixed antigen tray platform

This study aims at examining the clinical impact, of antibodies detected on an ELISA mixed antigen tray format (LATM, One Lambda) in the absence of complement dependent cytotoxicity (CDC) positivity. All patients who underwent renal transplantation in 2007 and 2008 had their final pre-transplant sera retrospectively analyzed by the LATM assay. These patients were then followed-up with clinical, biochemical, and histopathological end points defined by elevation of serum creatinine and/or histopathological criteria. Among 164 patients who were studied, 149 received grafts from live related donors and 15, from deceased donors. 31 (19%) of the transplanted patients demonstrated pre-transplant anti-HLA IgG antibodies on the assay. Totally, 15 were positive for class I antibodies, 4 for class II antibodies, and 12 for both class I and class II antibodies. 44 patients (36%) experienced rejection. 8 out of 31 (26%) ELISA positive patients and 36 out of 133 (27%) ELISA negative patients experienced rejection. Among 15 patients who received deceased donor transplants, 4 were positive for ELISA, and 11 were negative. All 4 (100%) of the ELISA positive patients experienced rejection as compared to 3 out of 11 (27%) ELISA negative patients (P = 0.01). The ELISA LATM assay did not show any predictive value for rejection in our overall patient population; however, results in the specific setting of deceased donor transplants merit further exploration.