International Standards for human Prolactin: calibration by international collaborative study

1989 ◽  
Vol 121 (1) ◽  
pp. 157-NP ◽  
Author(s):  
D. Schulster ◽  
R. E. Gaines Das ◽  
S. L. Jeffcoate
Keyword(s):  
Collaborative Study ◽  
Physicochemical Analysis ◽  
International Standards ◽  
World Health ◽  
Expert Committee ◽  
International Standard ◽  
Human Prolactin ◽  
Cell Assays ◽  
Reference Preparation ◽  
Health Organization

ABSTRACT Three ampouled preparations of purified human prolactin were assessed by 20 laboratories in eight countries for their suitability to serve as International Standards for the estimation of human prolactin in serum. Bioassays (pigeon crop sac assays and NB2 cell assays) were carried out in two laboratories, radioreceptor assays by one laboratory and radioimmunoassays by 17 laboratories. By physicochemical analysis the preparations appeared similar. Each preparation contained small amounts of contaminants and/or prolactin variants. No major differences among the three preparations were detected by immunoassay although, in one radioreceptor assay system, one of the preparations was found to differ from the other two. On the basis of all the available information, the Expert Committee on Biological Standardization of the World Health Organization (ECBS) in 1986 established the preparation in ampoules coded 83/562 as the Second International Standard for Prolactin and in October 1988 established the preparation in ampoules coded 84/500 as the Third International Standard for Prolactin. A value of 0·053 IU (53 mIU) prolactin activity/ampoule was assigned to both the Second and Third IS on the basis that this unitage would, insofar as possible, maintain continuity of the IU defined by the First International Reference Preparation of Prolactin, human, for Immunoassay (coded 75/504). Journal of Endocrinology (1989) 121, 157–166

Establishment of the second international standards for porcine and human calcitonins: report of the international collaborative study

1993 ◽  
Vol 128 (5) ◽  
pp. 443-450 ◽  
Author(s):  
Joan M Zanelli ◽  
Rose E Gaines-Das ◽  
P Corran
Keyword(s):  
World Health Organization ◽  
Collaborative Study ◽  
International Standards ◽  
World Health ◽  
International Reference ◽  
International Standard ◽  
Reference Preparation ◽  
Health Organization ◽  
International Collaborative Study

The biological potency of calcitonins in clinical use in long-term treatment of Paget's disease of bone and, increasingly, in osteoporosis is usually expressed in international units defined by the relevant World Health Organization international reference preparation. The international reference preparations for porcine and human calcitonins were ampouled in 1970 and stocks are now exhausted. Replacement standards were ampouled in 1989 and have been evaluated and calibrated by an international collaborative study comprising 16 laboratories in 12 countries. Evaluations included high-performance liquid chromatography and in vitro bioassay; calibration of each new ampouled preparation in terms of its international reference preparation was by in vivo rat hypocalcaemia bioassay. On the basis of the results of the study and with the agreement of the participants, replacement standards were established by the Expert Committee on Biological Standardization of the World Health Organization in 1991: the international standard for porcine calcitonin (ampoule code 89/540), with an assigned potency of 0.8 international units per ampoule, and the international standard for human calcitonin, with an assigned potency of 17.5 international units per ampoule. Both international standards appeared to be sufficiently stable to serve as the international standards for in vivo biological assays. Comparison of the two species of calcitonin in the same hypocalcaemia assay showed that they were approximately equipotent when the doses were given intravenously but that the human peptide was four- to sixfold more potent than porcine calcitonin when doses were given subcutaneously, emphasizing the need to compare "like with like".

A Collaborative Study of a Proposed International Standard for Tissue Plasminogen Activator (t-PA)

1985 ◽  
Vol 53 (01) ◽  
pp. 134-136 ◽  
Author(s):  
P J Gaffney ◽  
A D Curtis
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Collaborative Study ◽  
International Committee ◽  
World Health ◽  
Clot Lysis ◽  
Expert Committee ◽  
International Standard ◽  
Tissue Plasminogen ◽  
Health Organization

SummaryAn international collaborative study involving seven laboratories was undertaken to assess which of three lyophilised preparations might serve as an International Standard (I.S.) for tissue plasminogen activator (t-PA). Two of the preparations were isolates from human melanoma cell cultures while one was of pig heart origin. A clot lysis assay was used by all participants in the study.The data suggested that both preparations of human cell origin were comparable, in that their log dose-response lines were parallel, while that of the porcine preparation was not. Accelerated degradation studies indicated that one melanoma extract (denoted 83/517) was more stable than the other and it was decided to recommend preparation 83/517 as the standard for t-PA. The International Committee for Thrombosis and Haemostasis (Stockholm 1983) has recommended the use of this material as a standard and it has been established by the Expert Committee on Biological Standardization of the World Health Organization as the International, Standard for tissue plasminogen activator, with an assigned potency of 1000 International Units per ampoule.

The Second International Reference Preparation of Thyroid-Stimulating Hormone, Human, for Immunoassay: calibration by bioassay and immunoassay in an international collaborative study

1985 ◽  
Vol 104 (3) ◽  
pp. 367-379 ◽  
Author(s):  
R. E. Gaines Das ◽  
A. F. Bristow
Keyword(s):  
Collaborative Study ◽  
Thyroid Stimulating Hormone ◽  
World Health ◽  
Expert Committee ◽  
International Reference ◽  
Reference Preparation ◽  
International Collaborative ◽  
Health Organization ◽  
International Collaborative Study ◽  
Second International

ABSTRACT Four batches of ampouled materials in ampoules coded 80/558, 81/502, 81/565 and 81/615 were evaluated by 22 laboratories in nine countries in an international collaborative study for their suitability to serve as a replacement for the First International Reference Preparation (IRP) of TSH, Human, for Immunoassay. The ampouled preparations were calibrated by immunoassay and bioassay. The preparation coded 80/558 had satisfactory stability and contained acceptably low levels of contamination with FSH and LH. Estimates of the immunoreactive TSH content of a set of specimens of serum in terms of 80/558 showed agreement in ranking order and no increase in variability compared with estimates made by assay against the First IRP. On the basis of these results, with the agreement of the participants in the study, and with the authorization of the Expert Committee on Biological Standardization of the World Health Organization, the preparation coded 80/558 was established in 1983 as the Second International Reference Preparation of TSH, Human, for Immunoassay, with a defined potency of 37 mi.u./ampoule. Preparations coded 81/502, 81/565 and 81/615 were found suitable to serve as working standards. J. Endocr. (1985) 104, 367–379

Calibration of Reference Thromboplastins and Standardisation of the Prothrombin Time Ratio

1983 ◽  
Vol 49 (03) ◽  
pp. 238-244 ◽  
Author(s):  
T B L Kirkwood
Keyword(s):  
Prothrombin Time ◽  
Oral Anticoagulants ◽  
Collaborative Study ◽  
World Health ◽  
Expert Committee ◽  
Calibration Model ◽  
Biological Standardization ◽  
Reference Preparation ◽  
Health Organization ◽  
Practical Implications

SummaryThromboplastins vary in their sensitivity to the haemostatic defect induced by oral anticoagulants. To provide a means of standardising prothrombin time tests, the World Health Organization adopted in 1977 a scheme for calibrating thromboplastins in terms of an International Reference Preparation. Unfortunately, the model on which this scheme was based does not always hold. A revised calibration model has therefore been developed and this has been tested in a recent collaborative study. The revised model, which retains fundamentally the same principle for standardising prothrombin time tests, has proved suitable for calibrating thromboplastins of different species and types and, moreover, has certain statistical advantages over its predecessor. In September 1982, the WHO Expert Committee on Biological Standardization adopted the revised model. This paper explains the nature and rationale of this change and considers its practical implications.

INTERNATIONAL REFERENCE PREPARATION OF HUMAN PROLACTIN FOR IMMUNOASSAY: DEFINITION OF THE INTERNATIONAL UNIT, REPORT OF A COLLABORATIVE STUDY AND COMPARISON OF ESTIMATES OF HUMAN PROLACTIN MADE IN VARIOUS LABORATORIES

1979 ◽  
Vol 80 (1) ◽  
pp. 157-168 ◽  
Author(s):  
ROSE E. GAINES DAS ◽  
P. MARY COTES
Keyword(s):  
Human Plasma ◽  
Collaborative Study ◽  
World Health ◽  
Expert Committee ◽  
International Reference ◽  
Two Samples ◽  
Human Prolactin ◽  
Reference Preparation ◽  
Prolactin Content ◽  
Made In

As authorized by the World Health Organization 29th Expert Committee on Biological Standardization, the preparation of human prolactin in ampoules coded 75/504 has been established as the International Reference Preparation (IRP) of human prolactin for immunoassay. From the results of a collaborative study, to which 15 laboratories in nine countries contributed, with the agreement of the participants, the content of each ampoule is defined as 0·650 International Units (i.u.; 650 mi.u.) immunoassay. The results of this collaborative study show that the IRP is adequately stable and suitable for use as a standard for the determination of prolactin in human plasma and serum. Estimates of the prolactin content of human plasma and serum made in the various laboratories have been compared and show good agreement in ranking order, but only fair agreement in the numerical value of the estimates. Numerical agreement is poor between estimates of the human prolactin content of two samples identical except for coding; this shows the difficulty in achieving continuity of estimates when any laboratory calibrates a replacement standard.

An International Standard for whole blood folate: evaluation of a lyophilised haemolysate in an international collaborative study

2004 ◽  
Vol 42 (5) ◽  
Author(s):  
Susan J. Thorpe ◽  
Dawn Sands ◽  
Alan B. Heath ◽  
Malcolm S. Hamilton ◽  
Sheena Blackmore ◽  
...  
Keyword(s):  
Whole Blood ◽  
Collaborative Study ◽  
World Health ◽  
Expert Committee ◽  
International Standard ◽  
Accelerated Degradation ◽  
Biological Standardization ◽  
The World ◽  
Health Organization ◽  
International Collaborative Study

AbstractFolate measurements, particularly for whole blood, show wide inter-laboratory and inter-methodology variability. This variability appears to be due in part to the lack of internationally accepted reference materials. A whole blood haemolysate, lyophilised in ampoules and designated 95/528, was therefore evaluated by 15 laboratories in five countries for its suitability as an International Standard (IS) for whole blood folate. The preparation was assayed using a variety of microbiological and protein-binding methodologies against local standards and calibrators. A consensus folate content was assigned to 95/528. The inclusion of three whole blood samples in the study with widely differing folate levels demonstrated a considerable reduction in inter-laboratory variability when the folate content of the samples was determined relative to the proposed IS 95/528 rather than to laboratories' local standards and calibrators. Accelerated degradation studies indicated that the folate content of 95/528 is stable when stored at −20°C. On the basis of the results presented here, the World Health Organization Expert Committee on Biological Standardization established 95/528 as an IS for whole blood folate.

scholarly journals Characterization of Reference Materials for Human Antiserum to Pertussis Antigens by an International Collaborative Study

2008 ◽  
Vol 16 (3) ◽  
pp. 303-311 ◽  
Author(s):  
Dorothy Xing ◽  
Carl Heinz Wirsing von König ◽  
Penny Newland ◽  
Marion Riffelmann ◽  
Bruce D. Meade ◽  
...  
Keyword(s):  
Collaborative Study ◽  
International Standards ◽  
World Health ◽  
Enzyme Linked Immunosorbent Assay ◽  
Expert Committee ◽  
International Standard ◽  
Reference Serum ◽  
International Collaborative ◽  
International Collaborative Study

ABSTRACT Enzyme-linked immunosorbent assay (ELISA) has been widely used to evaluate antibody responses to pertussis vaccination and infection. A common reference serum is essential for the standardization of these assays. However, no internationally recognized reference serum is available. At the request of the Expert Committee on Biological Standardization (ECBS) of the World Health Organization (WHO), a set of four candidate international standards has been prepared. These candidate materials have been assessed for suitability and compared to the widely used U.S. reference pertussis antiserum (human) lot 3, lot 4, and lot 5 by 22 laboratories from 15 countries in an international collaborative study. Laboratories measured immunoglobulin G (IgG) and IgA antibodies to pertussis toxin (PT), filamentous hemagglutinin (FHA), pertactin (PRN), and fimbriae (Fim2&3) using their established immunoassays. The results of this study showed each of the four candidates to be suitable as an international standard. With the agreement of the participants, a recommendation has been made to the ECBS that the candidate material coded 06/140 be established as the First International Standard for pertussis antiserum (human), with the following assigned international units (IU): IgG anti-PT, 335 IU/ampoule; IgA anti-PT, 65 IU/ampoule; IgG anti-FHA, 130 IU/ampoule; IgA anti-FHA, 65 IU/ampoule; IgG anti-PRN, 65 IU/ampoule; and IgA anti-PRN, 42 IU/ampoule. No formal units have been proposed for anti-Fim2&3 because most assays used a mixture of fimbrial antigens. In addition, the candidate material coded 06/142 has been proposed as a WHO working preparation for characterization of assay systems.

scholarly journals The First WHO International Standard for Harmonizing the Biological Activity of Bevacizumab

Biomolecules ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1610
Author(s):  
Haiyan Jia ◽  
Parvathy Harikumar ◽  
Eleanor Atkinson ◽  
Peter Rigsby ◽  
Meenu Wadhwa
Keyword(s):  
Collaborative Study ◽  
Binding Activity ◽  
Relative Potency ◽  
World Health ◽  
Expert Committee ◽  
Binding Assays ◽  
International Standard ◽  
Global Harmonization ◽  
Health Organization ◽  
Endothelial Growth Factor

Several Bevacizumab products are approved for clinical use, with many others in late-stage clinical development worldwide. To aid the harmonization of potency assessment across different Bevacizumab products, the first World Health Organization (WHO) International Standard (IS) for Bevacizumab has been developed. Two preparations of a Bevacizumab candidate and comparator were assessed for their ability to neutralize and bind vascular endothelial growth factor (VEGF) using different bioassays and binding assays in an international collaborative study. Relative potency estimates were similar across different assays for the comparator or the duplicate-coded candidate sample. Variability in relative potency estimates was reduced when the candidate standard was used for calculation compared with various in-house reference standards, enabling harmonization in bioactivity evaluations. The results demonstrated that the candidate standard is suitable to serve as an IS for Bevacizumab, with assigned unitages for VEGF neutralization and VEGF binding activity. This standard coded 18/210 was established by the WHO Expert Committee on Biological Standardization, which is intended to support the calibration of secondary standards for product development and lifecycle management. The availability of IS 18/210 will help facilitate the global harmonization of potency evaluation to ensure patient access to Bevacizumab products with consistent safety, quality and efficacy.

A Collaborative Study to Establish the 2nd International Standard for Tissue Plasminogen Activator (t-PA)

1987 ◽  
Vol 58 (04) ◽  
pp. 1085-1087 ◽  
Author(s):  
P J Gaffney ◽  
A D Curtis
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Collaborative Study ◽  
Chinese Hamster ◽  
World Health ◽  
Clot Lysis ◽  
Expert Committee ◽  
Single Chain ◽  
International Standard ◽  
Tissue Plasminogen

SummaryAn international collaborative study involving ten laboratories located in eight different countries was undertaken in order to replace the current International Standard (I.S.) for tissue plasminogen activator (t-PA). Two lyophilised candidate preparations of high purity were assessed in comparison with the current I.S. for t-PA using only a clot lysis assay. One preparation (coded 861670) was purified from a cultured melanoma cell supernatant and was about 98% single chain t-PA while the other preparation (coded 861624) was derived from Chinese hamster ovary (CHO) cells following DNA recombinant procedures and was 75% single chain t-PA.Both candidate preparations of t-PA compared in quite a satisfactory manner with the current I.S. from the viewpoint of the biometrics of parallel line bioassays and both preparations were quite stable for long periods at low temperatures and stable from up to 1 month at temperatures of 20° and 38° C. Both fultil the criteria to serve as a satisfactory Znd International Standard for t-PA. The Fibrinolysis Subcommittee of the International Committee for Thrombosis and Haemostasis recommended the melanoma source t-PA (861670) as the next I.S. in order to maintain continuity with the 1st I.S. which was also a melanomatype preparation. The data from the ten laboratories indicated that each ampoule of the new proposed standard contains 850 international units of t-PA activity by the clot lysis assay. It is planned to present the results of this study to the Expert Committee on Biological Standardization of the World Health Organization at its next meeting and to request that the preparation of t-PA, coded 861670, be established as the 2ndlnternational Standard for t-PA.

A Collaborative Study to Establish an International Standard for Alpha-Thrombin

1992 ◽  
Vol 67 (04) ◽  
pp. 424-427 ◽  
Author(s):  
P J Gaffney ◽  
A B Heath ◽  
J W Fenton II
Keyword(s):  
Elevated Temperatures ◽  
Collaborative Study ◽  
World Health Organisation ◽  
Significant Loss ◽  
Thrombin Inhibitors ◽  
World Health ◽  
Expert Committee ◽  
International Standard ◽  
Assay Procedure ◽  
And Control

SummarySince 1975 an International Standard for Thrombin of low purity has been used. While this standard was stable and of value for calibrating thrombins of unknown potency the need for a pure a-thrombin standard arose both for accurate calibration and for precise measurement of thrombin inhibitors, notably hirudin. An international collaborative study was undertaken to establish the potency and stability of an ampouled pure a-thrombin preparation. A potency of 97.5 international units (95% confidence limits 86.5-98.5) was established for the new a-thrombin standard (89/ 588) using a clotting-assay procedure. Stability data at various elevated temperatures indicated that the standard could be transported and stored with no significant loss of potency.Ampoules of lyophilised a-thrombin (coded 89/588) have been recommended as an International Standard for a-thrombin with an assigned potency of 100 international units per ampoule by the International Society for Thrombosis and Haemostasis (Thrombin and its Inhibitors Sub-Committee) in Barcelona, Spain in July 1990 while the Expert Committee on Biological Standardisation and Control of the World Health Organisation will consider its status at its next meeting in Geneva in 1991.

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