The Molar Ratio of Retinol-Binding Protein to Transthyretin in the Assessment of Vitamin A Status in Adults. Proposal of a Cut-off Point

2002 ◽  
Vol 40 (12) ◽  
Author(s):  
Liliana B. Zago ◽  
Hernan Dupraz ◽  
María I. Sarchi ◽  
María E. Río
Keyword(s):  
Vitamin A ◽  
Binding Protein ◽  
Retinol Binding Protein ◽  
Molar Ratio ◽  
Vitamin A Status

scholarly journals Use of the retinol-binding protein : transthyretin ratio for assessment of vitamin A status during the acute-phase response

2000 ◽  
Vol 83 (5) ◽  
pp. 513-520 ◽  
Author(s):  
Suzanne M. Filteau ◽  
Juana F. Willumsen ◽  
Keith Sullivan ◽  
Karin Simmank ◽  
Mary Gamble
Keyword(s):  
Vitamin A ◽  
Sensitivity And Specificity ◽  
Assessment Tool ◽  
Binding Protein ◽  
Vitamin A Deficiency ◽  
Retinol Binding Protein ◽  
Serum Retinol ◽  
Vitamin A Status ◽  
Plasma Retinol

The ratio plasma retinol-binding protein (RBP) : transthyretin (TTR) has been proposed as a means to improve the assessment of vitamin A status of individuals with concurrent infection or inflammation. We have measured RBP and TTR in stored sera from South African children who had accidentally ingested kerosene. Samples were collected from these children in hospital when suffering acute inflammation and respiratory distress, and from them and neighbourhood control children 3 months later. Vitamin A status was defined by modified relative dose response (MRDR) tests of liver retinol stores at 3 months and by serum retinol concentration both when children were ill and when they were well. Illness was defined as either being in hospital or, at follow-up, as having a raised plasma α1-acid glycoprotein (AGP) level. The RBP : TTR value was significantly decreased by both illness and low liver retinol stores. When the effects on RBP : TTR of illness and vitamin A stores were considered together for the 3-month follow-up samples, only vitamin A status significantly decreased the value. We calculated sensitivity and specificity of the RBP : TTR ratio against established measures of vitamin A status using a cut-off value of 0·3 for RBP : TTR and standard cut-off values for MRDR (0·06) and plasma retinol (0·7 μmol/l). Compared with MRDR, RBP : TTR had sensitivities of 76 % and 43 % and specificities of 22 % and 81 % to detect vitamin A deficiency in hospitalized and well children respectively. Compared with plasma retinol, sensitivities were 88 % and 44 % and specificities were 55 % and 64 % in hospitalized and well children respectively. Only for the case of clinically well children with biochemical evidence of subclinical inflammation did sensitivity (62 % and 100 % against MRDR and plasma retinol respectively) and specificity (100 % and 60 % against MRDR and retinol) approach useful levels for an assessment tool. Overall, although a trend supporting the theory behind the use of the RBP : TTR for assessment of vitamin A status in infection was observed in the current study, the ratio did not provide adequate sensitivity and specificity to be a useful assessment tool.

Use of free and transthyretin-bound retinol-binding protein in serum as tests of vitamin A status in humans: effect of high creatinine concentrations in serum

1990 ◽  
Vol 36 (4) ◽  
pp. 674-676 ◽  
Author(s):  
B J Burri ◽  
D D Bankson ◽  
T R Neidlinger
Keyword(s):  
Renal Failure ◽  
Acute Renal Failure ◽  
Vitamin A ◽  
Serum Creatinine ◽  
Binding Protein ◽  
High Serum ◽  
Retinol Binding Protein ◽  
Creatinine Concentration ◽  
Vitamin A Status ◽  
Chromatographic Peaks

Abstract We measured immunologically active (apo + holo) retinol-binding protein (RBP), vitamin A-carrying (holo) free RBP, and transthyretin-bound (TTR) holo-RBP in serum from 34 retrospective cases of fluctuating acute renal failure. All subjects had high serum creatinine concentrations caused by renal failure. Apo + holo, holo-TTR-RBP, and (especially) holo-free RBP all correlated poorly but significantly with serum creatinine concentration. Therefore, the use of any form of RBP to measure vitamin A status may be of limited value in subjects with high creatinine concentrations in serum. However, molecular-exclusion HPLC may be able to distinguish increases in RBP concentration associated with renal failure from those caused by altered vitamin A status, because renal failure causes abnormalities in the number and retention times of chromatographic peaks as well as their areas.

scholarly journals Effect of vitamin A status at the end of term pregnancy on the saturation of retinol binding protein with retinol

2000 ◽  
Vol 71 (2) ◽  
pp. 537-543 ◽  
Author(s):  
Vincent Sapin ◽  
Marie C Alexandre ◽  
Samira Chaïb ◽  
Jean A Bournazeau ◽  
Patrick Sauvant ◽  
...  
Keyword(s):  
Vitamin A ◽  
Binding Protein ◽  
Retinol Binding Protein ◽  
Term Pregnancy ◽  
Vitamin A Status

Retinol-binding protein, retinol, and modified-relative-dose response in Ugandan children aged 12–23 months and their non-pregnant caregivers

2021 ◽  
pp. 153537022098547
Author(s):  
Ralph D Whitehead ◽  
Nicole D Ford ◽  
Carine Mapango ◽  
Laird J Ruth ◽  
Ming Zhang ◽  
...  
Keyword(s):  
Vitamin A ◽  
Dose Response ◽  
High Performance ◽  
Binding Protein ◽  
Retinol Binding Protein ◽  
Enzyme Linked Immunosorbent Assay ◽  
Vitamin A Status ◽  
Plasma Retinol ◽  
Commercial Enzyme Immunoassay ◽  
Modified Relative Dose Response

Retinol-binding protein (RBP), retinol, and modified-relative-dose response (MRDR) are used to assess vitamin A status. We describe vitamin A status in Ugandan children and women using dried blood spot (DBS) RBP, serum RBP, plasma retinol, and MRDR and compare DBS-RBP, serum RBP, and plasma retinol. Blood was collected from 39 children aged 12–23 months and 28 non-pregnant mothers aged 15–49 years as a subsample from a survey in Amuria district, Uganda, in 2016. DBS RBP was assessed using a commercial enzyme immunoassay kit, serum RBP using an in-house sandwich enzyme-linked immunosorbent assay, and plasma retinol/MRDR test using high-performance liquid chromatography. We examined (a) median concentration or value (Q1, Q3); (b) R2 between DBS-RBP, serum RBP, and plasma retinol; and (c) Bland-Altman plots. Median (Q1, Q3) for children and mothers, respectively, were as follows: DBS-RBP 1.15 µmol/L (0.97, 1.42) and 1.73 (1.52, 1.96), serum RBP 0.95 µmol/L (0.78, 1.18) and 1.47 µmol/L (1.30, 1.79), plasma retinol 0.82 µmol/L (0.67, 0.99) and 1.33 µmol/L (1.22, 1.58), and MRDR 0.025 (0.014, 0.042) and 0.014 (0.009, 0.019). DBS RBP-serum RBP R2 was 0.09 for both children and mothers. The mean biases were −0.19 µmol/L (95% limits of agreement [LOA] 0.62, −0.99) for children and −0.01 µmol/L (95% LOA −1.11, −1.31) for mothers. DBS RBP-plasma retinol R2 was 0.11 for children and 0.13 for mothers. Mean biases were 0.33 µmol/L (95% LOA −0.37, 1.03) for children, and 0.29 µmol/L (95% LOA −0.69, 1.27) for mothers. Serum RBP-plasma retinol R2 was 0.75 for children and 0.55 for mothers, with mean biases of 0.13 µmol/L (95% LOA −0.23, 0.49) for children and 0.18 µmol/L (95% LOA −0.61, 0.96) for mothers. Results varied by indicator and matrix. The serum RBP-retinol R2 for children was moderate (0.75), but poor for other comparisons. Understanding the relationships among vitamin A indicators across contexts and population groups is needed.

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