Thyroxine-binding globulin capacity and concentration evaluated from blood spots on filter-paper in a screening program for neonatal hypothyroidism.

Abstract We describe a simple method for evaluating thyroxine-binding globulin capacity and concentration from a single 1-cm blood spot on filter-paper used in a screening program for neonatal hypothyroidism. This method permits prompt diagnosis of about 90% of the infants with thyroxine-binding globulin deficiency in our abnormal low-thyroxine, low-thyrotropin population. There was excellent equivalence between results obtained by our method and by the method of Chopra et al. (J. Clin. Endocrinol. Metab. 35:565, 1972), and minimal overlap between the population with low thyroxine-binding globulin and the low-thyroxine, normal thyrotropin population. We recommend this method to all programs in which a primary thyroxine measurement is used in screening for congenital hypothyroidism.

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Blood-spot thyrotropin radioimmunoassay in a screening program for congenital hypothyroidism.

Clinical Chemistry ◽

10.1093/clinchem/25.6.933 ◽

1979 ◽

Vol 25 (6) ◽

pp. 933-938 ◽

Cited By ~ 8

Author(s):

W A Sadler ◽

C P Lynskey

Keyword(s):

Congenital Hypothyroidism ◽

Screening Program ◽

Rank Correlation ◽

Dried Blood Spots ◽

Recall Rate ◽

Factors Affecting ◽

Blood Spots ◽

Highly Sensitive ◽

Blood Spot ◽

Assay Conditions

Abstract We describe a highly sensitive and precise radioimmunoassay for thyrotropin in dried blood spots on filter paper cards. In a screening program for congenital hypothyroidism, blood-spot thyrotropin concentrations are measured in infants whose blood-spot thyroxine concentrations are in the lower 10%, and this strategy has reduced the recall rate from 1.7% (thyroxine assay alone) to 0.17%. Thyrotropin assay samples consist of discs 4.5-mm in diameter, containing about 6 microL of blood, punched from blood spots. By appropriate attention to assay conditions, a mean least-detectable thyrotropin concentration equivalent to 2.5 milliunits/L plasma has been achieved. Concomitant measurement of thyrotropin by plasma and blood-spot assays in 91 subjects yielded a Spearman rank correlation coefficient of 0.9732. An analysis of variance of the distribution volume of thyrotropin in blood spots and a covariance analysis of factors affecting blood-spot thyroxine results are presented.

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Radioimmunoassay of "free thyroxin" in dried blood spots on filter paper - preliminary observations on the effective differentiation of subjects with congenital hypothyroidism from those with subnormal thyroxin-binding globulin and normal subjects.

Clinical Chemistry ◽

10.1093/clinchem/28.3.505 ◽

1982 ◽

Vol 28 (3) ◽

pp. 505-508 ◽

Cited By ~ 8

Author(s):

H Mizuta ◽

K Miyai ◽

K Ichihara ◽

N Amino ◽

T Harada ◽

...

Keyword(s):

Congenital Hypothyroidism ◽

Filter Paper ◽

Normal Subjects ◽

Dried Blood Spots ◽

Free T4 ◽

Simple Method ◽

Blood Spots ◽

Coefficients Of Variation ◽

Secondary Hypothyroidism ◽

The Mean

Abstract In this sensitive, simple method for measuring "free thyroxin" (FT4) in eluates of dried blood spots on filter paper by use of a radioimmunoassay kit (Amerlex Free T4 RIA), the measurable range of FT4 is 1.8 to 57 ng/L (equivalent to the concentration in serum), or 7 to 237 fg/tube. The mean coefficients of variation for within assay-within spots, within assay-between spots, and between assays were 5.3%, 5.0%, and 6.2%, respectively. FT4 in blood spotted on filter paper is stable for at least a month when dried and kept at either -20 degrees C, 4 degrees C, room temperature (about 25 degrees C), or 37 degrees C. The results for FT4 in dried blood spots correlated closely with the free-T4 concentration in serum (r = 0.99). The method can be used to differentiate cases of primary and secondary hypothyroidism from normal subjects and those with subnormal thyroxin-binding globulin. This method may be useful in screening for congenital hypothyroidism, because sample-retesting is not necessary.

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Screening for Congenital Hypothyroidism With Specimen Collection at Two Time Periods: Results of the Northwest Regional Screening Program

PEDIATRICS ◽

10.1542/peds.76.5.734 ◽

1985 ◽

Vol 76 (5) ◽

pp. 734-740

Author(s):

Stephen H. LaFranchi ◽

Cheryl E. Hanna ◽

Patricia L. Krainz ◽

Michael R. Skeels ◽

Richard S. Miyahira ◽

...

Keyword(s):

Congenital Hypothyroidism ◽

Filter Paper ◽

Age Of Onset ◽

Screening Program ◽

Thyroid Tissue ◽

Cost Effective ◽

Thyroid Stimulating Hormone ◽

Primary Hypothyroidism ◽

Skeletal Maturation ◽

Second Screen

To determine the benefit of collecting two routine specimens to test for congenital hypothyroidism, we examined the results of our newborn screening program during the last 9.5 years. The Northwest Regional Screening Program (NWRSP) performs a primary thyroxine test with thyroid-stimulating hormone determinations on the lowest 10% of dried blood filter paper specimens. An initial specimen is obtained in the newborn period, and a routine second specimen is collected at approximately 4 to 6 weeks of age in all infants born in Oregon and 25% of infants born in Idaho, Montana, Alaska, and Nevada. Between May 1975 and October 1984, 182 infants with primary hypothyroidism were detected from 811,917 infants screened, a prevalence rate of 1:4,461. The routine second specimen led to the diagnosis of 19 infants of 484,604 infants screened, a detection rate of 1:25,505. When infants detected by the second screen were compared with those detected by the first screen, they had higher thyroxine and lower thyroidstimulating hormone concentrations on filter paper and serum specimens. When thyroid scanning was used, all but one infant detected by the second screen had some residual thyroid tissue, whereas 35% of infants detected by the first screen had thyroid aplasia. Skeletal maturation was more likely to be normal in infants detected by the second screen. These infants appear to have milder hypothyroidism due to a later age of onset or slower evolution of thyroid failure. At a cost of $31,881 per infant detected by the second screen, the NWRSP found it cost-effective to obtain a routine second specimen.

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Measurement of gonadotropins in dried blood spots

Clinical Chemistry ◽

10.1093/clinchem/40.3.448 ◽

1994 ◽

Vol 40 (3) ◽

pp. 448-453 ◽

Cited By ~ 37

Author(s):

C M Worthman ◽

J F Stallings

Keyword(s):

Luteinizing Hormone ◽

Filter Paper ◽

Clinical Studies ◽

Follicle Stimulating Hormone ◽

Dried Blood Spots ◽

Blood Spots ◽

Low Concentrations ◽

Serial Sampling ◽

Highly Correlated ◽

Blood Spot

Abstract We describe direct immunofluorometric assays for luteinizing hormone (hLH) and follicle-stimulating hormone (hFSH) in fingerstick blood spots dried on filter paper, based on modifications of commercially available kits. Determinations are made from 2.5-mm-diameter discs (3 microL of dried blood) punched out from blood spot standards and samples. Sample dose detection limits of the assays (IU/L) are 0.26 for LH and 0.13 for FSH, with mean interassay CVs of 11.6% (LH) and 7.8% (FSH) at low concentrations. Analytical recoveries of added hormone averaged 100% for LH and 95% for FSH. Clinical studies showed that values for blood spots (x) and directly assayed plasma (y) are highly correlated, so that results from blood spots can be converted directly to plasma equivalents, as follows: yLH = 0.07 + 1.90 xLH, and yFSH = 0.424 + 2.207 xFSH. These gonadotropins are stable in blood spots for at least a year under refrigeration; LH for at least 8 weeks and FSH 6 weeks at 22 degrees C; and both hormones for a week at 37 degrees C. These methods thus allow self-sampling, serial sampling, and mailing of specimens.

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Familial thyroxine-binding globulin deficiency detected in a pilot screening program for congenital hypothyroidism

Journal of Endocrinological Investigation ◽

10.1007/bf03350477 ◽

1982 ◽

Vol 5 (1) ◽

pp. 21-25 ◽

Cited By ~ 3

Author(s):

M. Carta Sorcini ◽

L. Moschini ◽

L. Fiore ◽

S. Tomarchio ◽

M. G. Di Iorio ◽

...

Keyword(s):

Congenital Hypothyroidism ◽

Screening Program ◽

Thyroxine Binding Globulin

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Clinical Effectiveness and Cost-Effectiveness of the Use of the Thyroxine/Thyroxine-Binding Globulin Ratio to Detect Congenital Hypothyroidism of Thyroidal and Central Origin in a Neonatal Screening Program

PEDIATRICS ◽

10.1542/peds.2004-2162 ◽

2005 ◽

Vol 116 (1) ◽

pp. 168-173 ◽

Cited By ~ 53

Author(s):

C. I. Lanting

Keyword(s):

Cost Effectiveness ◽

Congenital Hypothyroidism ◽

Neonatal Screening ◽

Screening Program ◽

Clinical Effectiveness ◽

Thyroxine Binding Globulin ◽

Central Origin ◽

Neonatal Screening Program

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Transient Neonatal Hypothyroidism Detected by Newborn Screening Program

PEDIATRICS ◽

10.1542/peds.60.4.538 ◽

1977 ◽

Vol 60 (4) ◽

pp. 538-541

Author(s):

STEPHEN H. LAFRANCHI ◽

NEIL R. M. BUIST ◽

WILLIAM H. MURPHEY ◽

P. REED LARSEN ◽

THOMAS P. FOLEY

Keyword(s):

Newborn Screening ◽

Filter Paper ◽

Metabolic Diseases ◽

Screening Program ◽

Newborn Infants ◽

Thyroid Stimulating Hormone ◽

Newborn Screening Program ◽

Neonatal Hypothyroidism ◽

Blood Samples ◽

Stimulating Hormone

A screening program for the detection of neonatal hypothyroidism has been in effect in Oregon since May 1975. Blood samples are obtained from all newborn infants to test for phenylketonuria and other metabolic diseases. A second specimen is obtained from more than 90% of these infants who are retested at 4 to 6 weeks of age. These Guthrie filter paper blood samples are analyzed for thyroxine (T4), and all samples with a low T4 value are analyzed for thyroid stimulating hormone (TSH). At the outset of the program, it was speculated that the screening might detect infants who had reduced

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Consequences of the Use of Low Blood-spot Thyroid-stimulating Hormone Cut-offs for the Neonatal Screening of Congenital Hypothyroidism

European Endocrinology ◽

10.17925/ee.2009.05.00.64 ◽

2009 ◽

Vol 05 (0) ◽

pp. 64

Author(s):

Luca Persani ◽

Davide Calebiro ◽

◽

Keyword(s):

Congenital Hypothyroidism ◽

Neonatal Screening ◽

Thyroid Stimulating Hormone ◽

Italian Population ◽

Neonatal Hypothyroidism ◽

Lombardy Region ◽

Increased Risk ◽

The Impact ◽

Blood Spot ◽

Stimulating Hormone

The consequences of using low blood-spot thyroid-stimulating hormone (b-TSH) cut-off values for newborn screening of congenital hypothyroidism (CH) are largely unknown. Therefore, the impact on CH epidemiology and classification generated by the introduction in our Italian region of a low b-TSH cut-off during 1999–2005 was retrospectively examined. This work was recently performed in collaboration with the Laboratory for Neonatal Screening and the Principal Follow-up Centre of the Lombardy region. The incidence of CH in this Italian population was 1:1,446 live births, with a predominance of functional over morphogenetic defects. The use of low b-TSH cut-offs allowed the detection of an unsuspected number of children with neonatal hypothyroidism, evolving to mild permanent thyroid dysfunction later in life. Premature birth was associated with a three- to five-fold increased risk of CH with glandin situ.

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Dried Blood Spots versus Sera for Detection of Rubella Virus-Specific Immunoglobulin M (IgM) and IgG in Samples Collected during a Rubella Outbreak in Peru

Clinical and Vaccine Immunology ◽

10.1128/cvi.00144-07 ◽

2007 ◽

Vol 14 (11) ◽

pp. 1522-1525 ◽

Cited By ~ 19

Author(s):

Rita F. Helfand ◽

Cesar Cabezas ◽

Emily Abernathy ◽

Carlos Castillo-Solorzano ◽

Ana Cecilia Ortiz ◽

...

Keyword(s):

Filter Paper ◽

Rubella Virus ◽

Dried Blood Spots ◽

Immunoglobulin M ◽

Dried Blood Spot ◽

Blood Spots ◽

Specific Immunoglobulin ◽

Blood Spot

ABSTRACT Most persons with rubella virus-specific immunoglobulin M (IgM)- or IgG-positive sera tested positive (98% [n = 178] and 99% [n = 221], respectively) using paired filter paper dried blood spot (DBS) samples, provided that DBS indeterminate results were called positive. For persons with IgM- or IgG-negative sera, 97% and 98%, respectively, were negative using DBS.

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