JP5259226B2 - Reagent for control sample preparation - Google Patents

Description

  The present invention relates to a reagent for preparing a control sample used for measuring glucose and / or hemoglobin A1c.

  Known markers for diabetes testing include glucose (blood glucose level), glycated hemoglobin, glycated albumin and the like. In particular, hemoglobin A1c, which is one type of glycated hemoglobin, has been established by HPLC, electrophoresis, enzyme, immunoassay, and the like, and is measured in the field of clinical examination. In order to improve the accuracy of the test, measurement of a plurality of markers is considered good. In particular, continuous measurement or simultaneous measurement of hemoglobin A1c and glucose (blood glucose level) is beneficial.

When measuring each marker, a calibration / correction operation such as calibration using a control sample containing a known amount of the marker substance to be measured is required. Various techniques relating to the control sample have been disclosed (Patent Document 1 and Patent Document 2).
Japanese Patent Application Laid-Open No. 2005-181128 Japanese Patent Laid-Open No. 10-017597

Currently, separate management samples are commercially available for each diabetes marker, and when measuring a plurality of diabetes markers, individual management by each management sample is required. For example, when measuring glucose, management by measurement of a management sample containing a known amount of glucose, and when measuring hemoglobin A1c, management by measurement of a management sample containing a known amount of hemoglobin A1c was separately required. .
In addition, such operation by measurement of the control sample requires measurement at a predetermined frequency in order to maintain high accuracy of inspection, but each control sample is very expensive, so the usage amount is suppressed. There is a concern that the measurement accuracy will decrease due to a decrease in the management level.

If there is a control sample containing both glucose and hemoglobin A1c, it is beneficial for cost reduction when measuring both. Further, if both methods are simultaneously measured, management can be performed by a single measurement using a management sample including both, and the operation time can be shortened.
However, since hemoglobin A1c is a reaction product of glucose and hemoglobin, when glucose and hemoglobin A1c coexist as a control sample, both react to each other during storage, and the concentrations of glucose and hemoglobin A1c change. There was a drawback.

  An object of the present invention is to provide a reagent for easily preparing a control sample that can be used in common when measuring glucose and / or hemoglobin A1c, which is an index for diagnosis of diabetes.

  Therefore, the present inventors examined the preparation of a control sample that can be used in common for glucose measurement and hemoglobin Alc measurement, and as a result, the preparation used for preparing a control sample for hemoglobin A1c measurement that has been conventionally used By including a known amount of glucose in the reagent, a management sample for conventional hemoglobin A1c measurement can be easily used in common for glucose measurement and hemoglobin A1c measurement by the same method as the preparation method. It was found that can be prepared.

  That is, the present invention is a reagent for preparing a control sample used for measurement of glucose and / or hemoglobin A1c, and contains a known amount of glucose having a final concentration in the range of 10 to 1000 mg / dL. A feature of the present invention is to provide a management sample preparation reagent.

  In the case of using the management sample preparation reagent of the present invention, it is possible to manage a known glucose and / or hemoglobin A1c measurement method by using a known hemoglobin A1c measurement management sample as it is. Moreover, since a control sample can be used in common for both measurements, it is advantageous in terms of cost. Moreover, since both are mixed immediately before a measurement, both content does not fluctuate by both coexistence.

The control sample preparation reagent of the present invention comprises a solution containing a known amount of glucose with a final concentration in the range of 10 to 1000 mg / dL.
The glucose contained in the management sample preparation reagent of the present invention is not particularly limited. In the glucose measurement method using the management sample prepared by the management sample preparation reagent of the present invention, Any glucose that can be measured in the same manner as the sample to be measured may be used. More preferably, it is a high-purity product such as high-purity glucose used for the current glucose measurement management sample.

The concentration of glucose contained in the control sample preparation reagent of the present invention is not particularly limited as long as the final concentration is within the range of 10 to 1000 mg / dL.
The above final concentration is the concentration when diluted by adding to a hemoglobin A1c management sample described later. For example, 2.0 mL of the management sample preparation reagent of the present invention is added to 0.2 mL of hemoglobin A1c management sample to prepare glucose and / or hemoglobin A1c measurement management sample containing glucose at a final concentration of 100 mg / dL. In this case, the management preparation reagent of the present invention may contain 110 mg / dL of glucose.
Since the final concentration of glucose outside the above range deviates from the range of measurement values of healthy human samples and many diabetic patient samples, it is not preferable because correction or calibration by a control sample in a glucose measurement system is difficult.

  In addition, when a control sample prepared using the control preparation reagent of the present invention is used for measurement of glucose and / or hemoglobin A1c, a plurality of control samples having one or more known concentrations are prepared for measurement. May be provided. When preparing a control sample having two or more concentrations, a plurality of control sample adjusting reagents containing glucose at the concentration may be prepared and prepared. Even when provided as a plurality of control samples having known concentrations, the glucose concentration of all control sample preparation reagents needs to have a final concentration in the range of 10 to 1000 mg / dL.

The reagent for preparing a control sample of the present invention is not particularly limited except that it contains glucose at the above concentration, and there are no restrictions on the pH, composition, etc. of the reagent. It is only necessary that the management sample obtained by the management sample preparation reagent of the present invention described later can perform the same measurement as the measurement sample. Preferably, it is an aqueous solution or buffer solution containing a known concentration of glucose. If necessary, a substance having a stabilizing action such as a preservative, a surfactant having a hemolytic action such as polyoxyethylene alkylphenyl ether, and the like may be added.
In the case of using a buffer solution, any composition and physical properties that do not hinder measurement when measuring a control sample obtained by the control sample preparation reagent of the present invention may be used. Moreover, it is good also as a buffer solution same as or similar to the buffer solution used for a measurement system. As the buffer solution, a buffer solution containing a buffering agent having a buffer capacity in the range of pH 4.0 to 10.0, and further pH 5.0 to 9.0 is preferable. Examples of such buffers include organic acids such as citric acid, succinic acid, tartaric acid and malic acid and salts thereof; amino acids such as glycine, taurine and arginine; hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, boric acid and acetic acid. And amphoteric buffer solutions such as Good's buffer solution.

  The management sample prepared by the management sample preparation reagent of the present invention is a hemoglobin-containing sample containing a known amount of hemoglobin A1c suitable for management. The hemoglobin A1c concentration suitable for preferable management is 3 to 15%. A hemoglobin-containing sample having a hemoglobin A1c concentration that deviates from the above range is not suitable for use as a management sample because it deviates from the measurement values of healthy persons and diabetic patients in a normal examination. The hemoglobin-containing sample may be a solution or a lyophilized product. As the hemoglobin-containing sample, a known standard sample that is currently used for management when measuring hemoglobin A1c can be used. That is, a hemoglobin-containing sample containing a known amount of hemoglobin A1c derived from human blood, which is used as a control sample when measuring hemoglobin A1c by HPLC, electrophoresis, immunization, enzyme method, or the like can be used. .

  The reagent for preparing a control sample of the present invention is particularly effective when measuring both glucose and hemoglobin A1c simultaneously or successively. It can also be used for measuring only glucose or measuring only hemoglobin A1c.

The management sample is preferably prepared by the management sample preparation reagent of the present invention immediately before the measurement. Specifically, the measurement is preferably performed within 24 hours after the preparation of the control sample using the control sample preparation reagent of the present invention. When 24 hours or more have elapsed after preparation, hemoglobin reacts with glucose in the control sample, and the glucose concentration and hemoglobin A1c value fluctuate, which may impair accuracy control. More preferably, the measurement needs to be performed within 12 hours after preparation.
In general, the preparation of the control sample used in the current method for measuring hemoglobin A1c is usually performed immediately before the measurement, and therefore the preparation method using the reagent of the present invention is also the same.

  The method for measuring glucose using the control sample prepared by the control sample preparation reagent of the present invention is not particularly limited, and a known method is used. Preferred are a method using an enzyme such as hexokinase, glucose oxidase, glucose hydrogenase, glucokinase, a method using an immobilized enzyme in which these enzymes are immobilized, or a method using an enzyme electrode. The enzyme electrode method using glucose oxidase is preferable.

Moreover, there is no restriction | limiting in particular as a measuring method of hemoglobin A1c using the management sample for diabetes tests prepared with the management sample preparation reagent of this invention, A well-known method is used. Preferably, HPLC method, enzyme method, electrophoresis method, immunization method and the like can be mentioned. Particularly preferred are HPLC and enzymatic methods.
By using the control sample prepared by the control sample preparation reagent of the present invention, glucose and / or hemoglobin A1c can be measured.

Furthermore, glucose and hemoglobin A1c may be measured continuously or simultaneously using the control sample prepared by the control sample preparation reagent of the present invention. For example, a measuring device in which a glucose measuring device by an enzyme method and a hemoglobin A1c (diabetic marker other than glucose) measuring device by an HPLC method are connected by a transport device, and a simultaneous measuring method of glucose and hemoglobin A1c by an enzymatic method are disclosed. Using the control sample prepared with the control sample preparation reagent of the present invention, a continuous or simultaneous measurement method using these measuring devices can be performed. In the case of these continuous measurement methods and simultaneous measurement methods, the principle of each measurement method is not limited, and measurement can be performed by combining known measurement methods.
The control sample prepared by the control sample preparation reagent of the present invention is particularly useful for the continuous measurement method or simultaneous measurement method of glucose and hemoglobin A1c.

  EXAMPLES Next, although an Example is given and this invention is demonstrated further in detail, this invention is not limited to this at all.

Example 1
Glucose (NIST standard: HECTEF SRM917) dissolved in 50 mM phosphate buffer (pH 7.0) containing 77 mg / dL and 0.01% Triton X-100 (Wako Pure Chemicals: Surfactant) A sample preparation reagent was prepared.
Control sample for hemoglobin A1c measurement (Glyco Hb control manufactured by Sysmex: hemoglobin A1c value is 5.0%) 1 vial was dissolved by adding 0.2 mL of distilled water, and then 0.2 mL of the resulting solution was added to 0.2 mL On the other hand, 2 mL of the reagent for preparing the control sample was added to prepare a control sample for measuring glucose and hemoglobin A1c containing a final glucose concentration of 70 mg / dL and hemoglobin A1c 5.0%.
Similarly, a reagent for preparing a control sample containing 143 mg / dL of glucose is prepared and added to the control sample (the same: hemoglobin A1c value is 11.0%) to obtain a final glucose concentration of 130 mg / dL and hemoglobin A1c of 11.0%. A control sample containing was prepared.

  The two types of control samples obtained above were measured with a glucose measuring device and a hemoglobin A1c measuring device. As a measuring device, a glucose measuring device (ARKRAY GA-1170: enzyme electrode method) and a hemoglobin A1c measuring device (ARKRAY HA-8170: HPLC method) were used.

The correction formula was calculated so that each numerical value obtained as a result of the measurement was a reference value, that is, a glucose concentration of 70 mg / dL and 130 mg / dL, respectively, and a hemoglobin A1c value of 5.0% and 11.0%, respectively.
Subsequent to the measurement of the control sample, a measurement sample obtained by collecting sodium fluoride from healthy subjects and diabetic patients was measured by a conventional method of each measuring device. The correction value was calculated by substituting the measurement value of the obtained measurement sample into the correction equation. The obtained results are shown in Table 1.

(Example 2)
The above except that the clinical analyzer S40 (manufactured by Daiichi Chemicals: hexokinase method) was used as the glucose measuring device, and the Hitachi 7170 automatic analyzer (Nordia HbA1c: manufactured by Daiichi Chemicals: enzymatic method) was used as the hemoglobin A1c measuring device. The same sample was measured by the same operation as in Example 1. The obtained results (correction values) are shown in Table 1.

(Example 3)
As an apparatus for measuring glucose and hemoglobin A1c, an apparatus disclosed in Japanese Patent Application Laid-Open No. 2007-155684 (improved BF-3T manufactured by Oji Scientific Instruments, and an enzymatic method for both glucose and hemoglobin A1c) was used. The same sample was measured by the same operation as in Example 1 above. The obtained results (correction values) are shown in Table 1.

  As shown in Table 1, as a result of performing the correction using the control sample preparation reagent of the present invention, the measured values became the same, indicating that the glucose and hemoglobin A1c values can be corrected. That is, it was confirmed that the control sample prepared by the control sample preparation reagent of the present invention can be used in common for both measurement of glucose and hemoglobin A1c.

Claims (5)

A reagent for preparing a control sample commonly used for measurement of hemoglobin Alc and glucose, which is an index for diagnosis of diabetes , and containing a known amount of glucose with a final concentration in the range of 10 to 1000 mg / dL , 24 hours prior within, der Ru manage sample preparation reagents shall be used as a mixture with hemoglobin containing samples containing known amounts of hemoglobin Alc measurement. Control sample preparation reagent according to claim 1 hemoglobin Alc concentration a known amount of 3 to 15%. A method for preparing a control sample commonly used for hemoglobin Alc measurement and glucose measurement as an index for diagnosis of diabetes, wherein a hemoglobin-containing sample containing a known amount of hemoglobin Alc is charged within 24 hours before the measurement. A method comprising adding the reagent for preparing a control sample according to Item 1. The method according to claim 3, wherein the known amount of hemoglobin Alc concentration is 3 to 15%. A continuous measurement method or simultaneous measurement method of glucose and hemoglobin A1c using the control sample obtained by the control sample preparation reagent according to claim 1 or 2 or prepared by the method according to claim 3 or 4 .