Surfactant “apoproteins” in human amniotic fluid: An enzyme-linked immunosorbent assay for the prenatal assessment of lung maturity

Shelley, Sue A.; Balis, John U.; Paciga, June E.; Knuppel, Robert A.; Ruffolo, Eugene H.; Bouis, Pierre J.

doi:10.1016/0002-9378(82)90632-9

Cited by 43 publications

(19 citation statements)

References 17 publications

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“…The purity of our reference preparation was evaluated by 2-dimensional gel electrophoresis and its protein concentration was assessed by repeated protein measurements throughout the study. We also first detected an increase in the SP-A amniotic fluid concentration at about 32-33 wk of gestation, somewhat earlier than is apparent from the data presented by McMahan et al (9) and Kuroki et al (7), yet similar to the data reported by Shelley et al (6). The temporal patterns of the increase in amniotic fluid surfactant apoprotein concentration in the present study were similar when expressed per ml or per mg protein.…”

Section: Resultssupporting

confidence: 90%

“…Thus, there is abundant evidence that SP-A is an integral component of lamellar bodies, the intracellular storage form of surfactant, and of secreted alveolar surfactant. It is not surprising, therefore, that the amniotic fluid concentration of SP-A increases as a function of gestational age (5)(6)(7)(8)(9). The temporal pattern of the increase in amniotic fluid SP-A observed in our study is comparable to that reported by McMahan et al (9) and Kuroki et al (7), although we detected somewhat higher concentrations of SP-A in amniotic fluid than did these investigators.…”

Section: Resultsmentioning

confidence: 99%

“…The most commonly used means of assessing fetal lung maturation is the determination of the L/S ratio, an index of the amniotic fluid concentration of surfactant-derived saturated phosphatidylcholine relative to sphingomyelin, a phospholipid whose concentration in amniotic fluid does not change as a function of gestational age (4). Several investigators have reported that the concentration of the 35,000 mol wt SP-A in amniotic fluid increases as a function of gestational age, similar to the increase in surfactant phospholipid (5)(6)(7)(8)(9). Recently, low rnol wt, hydrophobic SP-B and SP-C have been described (10, 1 I).…”

Section: The Cecil H and Ida Green Center For Reproductive Biology Smentioning

confidence: 99%

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The Concentration of the 35-kDa Surfactant Apoprotein in Amniotic Fluid from Normal and Diabetic Pregnancies

et al. 1988

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ABSTRACT. A specific, enzyme-linked immunoabsorbent assay was used to determine the concentration of the 35,000 mol wt surfactant apoprotein (SP-A) in samples of amniotic fluid obtained from nondiabetic (n = 358) and diabetic (n = 29) women. The enzyme-linked immunoabsorbent assay was performed with rabbit antibodies directed against SP-A present in lavage fluid from a patient with alveolar proteinosis. Amniotic fluid SP-A concentrations increased as a function of gestational age, from <3 jtg/ml at 30-31 wk to 24 pg/ml at 40-41 wk, and were positively correlated with the lecithin to sphingomyelin ratio ( p < 0.01). SP-A concentrations also increased as a function of gestational age in shake test positive samples ( p < 0.05), but were unchanged in shake test-negative samples. There was no difference in the surfactant apoprotein concentration of male compared with female fetuses at any gestational age. In amniotic fluid obtained from 20 diabetic women, SP-A levels were significantly less than in nondiabetic pregnancies that were matched for gestational age and sex of the fetus ( p < 0.05). The SP-A concentrations in amniotic fluids obtained from nine women who were diabetic and hypertensive and from 10 hypertensive women were not different from matched controls. The relationships described above were valid whether the SP-A concentration was expressed per mg protein or per ml amniotic fluid. These data are suggestive that the concentration of amniotic fluid SP-A is decreased in diabetic pregnancies. (Pediafr Res 24: 728-734, 1988)

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Section: Resultssupporting

confidence: 90%

Section: Resultsmentioning

confidence: 99%

Section: The Cecil H and Ida Green Center For Reproductive Biology Smentioning

confidence: 99%

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The Concentration of the 35-kDa Surfactant Apoprotein in Amniotic Fluid from Normal and Diabetic Pregnancies

et al. 1988

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“…Amniotic fluid content of saturated phosphatidylcholine (lecithin), PG, and phosphatidylinositol parallel the expression of these phospholipids in the fetal lung and have been used to estimate fetal lung maturity (8-13). Human amniotic fluid content of SP-A also increases with advancing gestation and is predictive of fetal lung maturity and development of RDS (14)(15)(16)(17)(18).…”

Section: [Sp-a] Sp-a Concentration [Sp-b] Sp-b Concentrationmentioning

confidence: 99%

Ontogeny of Surfactant Proteins A and B in Human Amniotic Fluid as Indices of Fetal Lung Maturity

et al. 1991

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ABSTRACT. Surfactant proteins A and B (SP-A and SP-B) were measured in human amniotic fluid by ELISA and correlated with lecithin to sphingomyelin ratio (L/S), phosphatidylglycerol (PG), and perinatal outcome. Amniotic fluid SP-A, SP-B, and L/S increased with advancing gestation. SP-A was detected at 19 wk gestation and increased dramatically in the 3rd trimester of pregnancy. SP-B was first detectable at 31 wk gestation and increased significantly to term. SP-A was a more specific predictor of nonrespiratory distress syndrome (RDS) than L/S or SP-B; however, the sensitivity of SP-A in predicting RDS was less than L/S < 2.0 (26.3 versus 82.3%, respectively). In 209 pregnancies assessed within 48 h of delivery, the sensitivity of SP-B in predicting RDS (nondetectable SP-B) was comparable to the L/S, however, SP-B = 0 was frequently observed in mature infants, limiting its specificity for prediction of RDS. The greatest sensitivity and specificity were achieved with the measurement of L/S < 3). SP-B is an M, = 8700 hydrophobic polypeptide that imparts biophysical properties of rapid spreading and adsorption to surfactant phospholipids (for review, see Ref. 4). The surfactant phospholipids and associated proteins are developmentally regulated, appearing in the fetal rat lung between 18 and 19 d of gestation and increasing until birth (5-7). Lung fluid, including surfactant, contributes to the composition of amniotic fluid. Amniotic fluid content of saturated phosphatidylcholine (lecithin), PG, and phosphatidylinositol parallel the expression of these phospholipids in the fetal lung and have been used to estimate fetal lung maturity (8-13). Human amniotic fluid content of SP-A also increases with advancing gestation and is predictive of fetal lung maturity and development of .RDS continues to be a major cause of morbidity and mortality in premature infants. Accurate estimates of fetal lung maturity are required for optimal pennatal-neonatal management of highrisk pregnancies. The L/S and the presence of P C are routinely used to predict the development of RDS (9, 1 1, 14). The accuracy of the combined L/S and P C tests is approximately 90-95%. A high incidence of false-negative results occurs particularly with the L/S, such that fetal lung immaturity is predicted in many cases where neonatal pulmonary function is mature. In the present study, concentrations of SP-A and SP-B in human amniotic fluid were determined by capture ELISA. The predictive value of the amniotic fluid concentration of SP-A and SP-B for neonatal pulmonary disease was compared with that of the L/S and PC. MATERIALS AND METHODSAmniotic fluid samples (n = 473) were obtained from 408 high-risk pregnancies at the University of Cincinnati between

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“…Its concentration in amniotic fluid increases during the third trimester of gestation parallelling the increase in surfactant phospholipids during that period [7,13,23], Measurement of the SP-A concentration in amniotic fluid has therefore been used to assess lung maturity [11,12,14,22].…”

Section: Introductionmentioning

confidence: 99%

Surfactant protein A in the course of respiratory distress syndrome

et al. 1992

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Abstract. Surfactant-associated protein (SP-A) was measured in tracheal aspirates of ventilated infants with (n = 51) and without (n = 21) respiratory distress syndrome (RDS). SP-A concentrations in samples collected after birth were significantly lower in RDS than in infants ventilated for other reasons than RDS (median 0.03 vs. 1.60 gg/ml). As a biochemical test to diagnose RDS early after birth, the sensitivity of measuring SP-A in tracheal aspirates was 87% and specificity 81%. SP-A content in tracheal aspirates of infants with RDS was monitored during the first 7 days of life. A significant (P < 0.001) increase within the first 4 days was found in those infants who survived, whereas no such change was found in those infants who died.

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Surfactant “apoproteins” in human amniotic fluid: An enzyme-linked immunosorbent assay for the prenatal assessment of lung maturity

Cited by 43 publications

References 17 publications

The Concentration of the 35-kDa Surfactant Apoprotein in Amniotic Fluid from Normal and Diabetic Pregnancies

The Concentration of the 35-kDa Surfactant Apoprotein in Amniotic Fluid from Normal and Diabetic Pregnancies

Ontogeny of Surfactant Proteins A and B in Human Amniotic Fluid as Indices of Fetal Lung Maturity

Surfactant protein A in the course of respiratory distress syndrome

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