Soluble fms-like tyrosine kinase 1 (sFlt-1): A novel biochemical marker for acute fatty liver of pregnancy.

INTRODUCTION: Acute fatty liver of pregnancy (AFLP) substantially contributes to maternal and neonatal morbidity and mortality. Other liver-associated pregnancy complications such as preeclampsia-associated HELLP (hemolysis, elevated liver enzyme, low platelet) syndrome may be difficult to differentiate from AFLP as these diseases overlap with regard to multiple clinical and laboratory features. The aim of this study was to investigate angiogenic profiles by measuring soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) in pregnancies compromised by AFLP and to compare them with those complicated by HELLP syndrome. MATERIAL AND METHODS: Pregnant women affected by AFLP or HELLP syndrome were enrolled. The study population of women with HELLP syndrome was part of a larger data collection obtained in our clinic that has been used for previous work. Patients' angiogenic profiles were assessed by measuring sFlt-1 and PlGF serum levels. To assess the diagnostic potential of these angiogenic markers in AFLP, as well as discriminating it from HELLP syndrome, non-parametric tests were used and receiver operating curves were calculated. RESULTS: Six women with AFLP and 48 women with HELLP syndrome were included in the study. Patients with AFLP showed significantly higher sFlt-1 levels (median: 57 570 pg/mL; range 31 609-147 170 pg/mL) than patients with HELLP syndrome (9713 pg/mL; 1348-30 781 pg/mL; p < 0.001). PlGF serum levels were higher in patients with AFLP compared with those with HELLP syndrome (197 pg/mL; 127-487 pg/mL vs. 40 pg/mL; 9-644 pg/mL, respectively; p < 0.01). sFlt-1/PlGF ratios were not significantly different between AFLP and HELLP syndrome patients (192; 157-1159 vs. 232; 3-948, respectively; NS). In our study population, an sFlt-1 cut-off value of 31 100 pg/mL allowed differentiation between these two diseases with a sensitivity and specificity of 100%. A linear correlation was found between the cumulative numbers of Swansea criteria and sFlt-1 serum levels (r = 0.97; p < 0.01). CONCLUSIONS: AFLP is associated with very high sFlt-1 serum levels in particular in women fulfilling eight or more Swansea criteria. Besides the suggested Swansea criteria to diagnose AFLP, an sFlt-1 value above 31 100 pg/mL may be an additional biochemical feature improving discrimination between AFLP and HELLP syndrome. However, because of the small number of pregnancies affected by AFLP included in this work further studies are needed to corroborate our findings.

Diagnostic Accuracy of Holotranscobalamin, Vitamin B12, Methylmalonic Acid, and Homocysteine in Detecting B12 Deficiency in a Large, Mixed Patient Population.

Four biomarkers are commonly employed to diagnose B12 deficiency: vitamin B12 (B12), holotranscobalamin (HoloTC), methylmalonic acid (MMA), and homocysteine (Hcy). 4cB12, a combined index of the B12 status, has been suggested to improve the recognition of B12 deficiency. We aimed to evaluate the four different markers for detecting B12 deficiency, as determined by 4cB12. Within a large, mixed patient population, 11,833 samples had concurrent measurements of B12, HoloTC, MMA, and Hcy. 4cB12 was calculated according to the methods described by Fedosov. Diagnostic cutoffs as well as diagnostic accuracy for the detection of B12 deficiency were assessed with receiver operating characteristic (ROC) analysis. The median age was 56 years, and women accounted for 58.8% of the samples. Overall, the area under the curve (AUC) for the detection of subclinical B12 deficiency was highest for HoloTC (0.92), followed by MMA (0.91), B12 (0.9) and Hcy (0.78). The difference between HoloTC and B12 was driven by a significantly higher AUC for HoloTC (0.93) than for B12 (0.89), MMA (0.91), and Hcy in women 50 years and older (0.79; p < 0.05 for all). In the detection of subclinical B12 deficiency, there were no significant differences in the AUCs of HoloTC, B12, and MMA among men and women <50 years. In conclusion, in women < 50 years and in men, HoloTC, MMA, or Hcy do not appear superior to B12 for the detection of B12 deficiency. For women 50 years and older, HoloTC seems to be the preferred first-line marker for the detection of subclinical B12 deficiency.

Shrunken pore syndrome, preeclampsia, and markers of NO metabolism in pregnant women during the first trimester.

Shrunken pore syndrome (SPS) is a condition that manifests itself as the decreased renal clearance of low-molecular-weight proteins but normal clearance of creatinine. Pregnant women with evidence of SPS during the first trimester have an increased risk of developing preeclampsia (PE). The nitric oxide (NO) metabolism markers arginine and ADMA, especially their ratio (Arg/ADMA), are recognized markers of endothelial dysfunction. The aim of this nested case-control study was to establish first-trimester reference intervals (RI) for markers of NO metabolism and to study these markers in women with evidence of SPS at the end of the first trimester. Seventy-four women were stratified in the first trimester according to evidence of SPS (SPS + or SPS-) and the occurrence of PE during subsequent pregnancy (PE + or PE-), as follows: SPS-/PE-, SPS+/PE-, SPS-/PE+, and SPS+/PE+. RIs were determined according to the CLSI EP28-A3c guidelines. Serum Arg and ADMA levels were analyzed. The Arg and ADMA concentrations did not differ among the four groups. However, women in the SPS+/PE + group had a significantly lower Arg/ADMA ratio than those in the other 3 groups (p = .02). In conclusion, we defined the first-trimester RI of Arg, ADMA and the Arg/ADMA ratio as markers of NO metabolism. Our results suggest that SPS in the first trimester predicts a pathophysiological hallmark of subsequent PE, i.e. lower NO production leading to increased vessel tone. Early identification of women at risk for later PE could lead to adaptive prophylactic interventions, such as supplementation with Arg or an NO-donor drug in order to mitigate the risk of developing PE.