Utility of Plasma Cell Screening Tube Kit to Differentiate Neoplastic Plasma Cells from Reactive Plasma Cells

Flow cytometry is a powerful tool for analysis of hematologic malignancies, that provides rapid, quantitative, and multiparametric analysis of heterogeneous cell populations, but requires standardization because of complexities in panel design and interpretation. Here, we compared the Plasma Cell Screening Tube (PCST) kit (Cytognos, Spain) in conjunction with EuroFlow antibody panels for standardization of flow cytometry to a conventional method for diagnosis of plasma cell dyscrasias. Thirty-nine bone marrow samples and one peripheral blood sample from 40 patients were tested. Thirty-three patients were diagnosed with multiple myeloma (MM), and seven were in a reactive state. In PCST implementation, eight antibodies were used for staining, including anti-CD45-Pacific Blue, anti-CD19-PECy7, anti-CD138-OC515, anti-CD38-FITC, anti-CD56-PE, anti-β2-microglobulin-PerCPCy5.5, anti-kappa-APC, and anti-lambda-APC-C750. Plasma cells were initially identified using CD38 and CD138; thereafter, CD38+, CD138+ gated cells were analyzed for CD56, CD19, CD45, cytoplasmic kappa, cytoplasmic lambda, and β2-microglobulin. Conventional flow cytometry was performed with six monoclonal antibodies, including anti-CD56-FITC, anti-kappa-FITC, anti-CD19-PE, anti-lambda-PE, anti-CD138-PECy5, and anti-CD45-PECy7 (Beckman Coulter, USA). Monoclonal plasma cells with cytoplasmic light-chain restriction were detected in 30 of 33 (90.9%) MM cases by conventional methods, and 32 of 33 (97.0%) MM cases with the PCST method. No differences were noted between PCST and the conventional method in immunophenotyping and plasma cell percentages (P=0.323). Among plasma cells, levels (%) were significantly higher by the PCST approach than those in the conventional method (97.6% vs 95.8%, P=0.010). PCST exhibited better performance for plasma cell dyscrasias diagnosis, and could improve laboratory efficiency and quality.

Utility of Plasma Cell Screening Tube Kit to Differentiate Neoplastic Plasma Cells from Reactive Plasma Cells

Flow cytometry is a powerful tool for analysis of hematologic malignancies, that provides rapid, quantitative, and multiparametric analysis of heterogeneous cell populations, but requires standardization because of complexities in panel design and interpretation. Here, we compared the Plasma Cell Screening Tube (PCST) kit (Cytognos, Spain) in conjunction with EuroFlow antibody panels for standardization of flow cytometry to a conventional method for diagnosis of plasma cell dyscrasias. Thirty-nine bone marrow samples and one peripheral blood sample from 40 patients were tested. Thirty-three patients were diagnosed with multiple myeloma (MM), and seven were in a reactive state. In PCST implementation, eight antibodies were used for staining, including anti-CD45-Pacific Blue, anti-CD19-PECy7, anti-CD138-OC515, anti-CD38-FITC, anti-CD56-PE, anti-β2-microglobulin-PerCPCy5.5, anti-kappa-APC, and anti-lambda-APC-C750. Plasma cells were initially identified using CD38 and CD138; thereafter, CD38+, CD138+ gated cells were analyzed for CD56, CD19, CD45, cytoplasmic kappa, cytoplasmic lambda, and β2-microglobulin. Conventional flow cytometry was performed with six monoclonal antibodies, including anti-CD56-FITC, anti-kappa-FITC, anti-CD19-PE, anti-lambda-PE, anti-CD138-PECy5, and anti-CD45-PECy7 (Beckman Coulter, USA). Monoclonal plasma cells with cytoplasmic light-chain restriction were detected in 30 of 33 (90.9%) MM cases by conventional methods, and 32 of 33 (97.0%) MM cases with the PCST method. No differences were noted between PCST and the conventional method in immunophenotyping and plasma cell percentages (P=0.323). Among plasma cells, levels (%) were significantly higher by the PCST approach than those in the conventional method (97.6% vs 95.8%, P=0.010). PCST exhibited better performance for plasma cell dyscrasias diagnosis, and could improve laboratory efficiency and quality.

A Case of Lymphoplasmacytic Lymphoma/Waldenström's Macroglobulinemia with IgM-κ and IgA-λ Biclonal Gammopathy

Lymphoplasmacytic lymphoma (LPL) is a low-grade B-cell neoplasm, composed of small B lymphocytes, plasmacytoid lymphocytes, and plasma cells, usually involving bone marrow and sometimes lymph nodes or spleen. LPL with bone marrow involvement and an IgM monoclonal gammopathy of any concentration is designated as Waldenström macroglobulinemia (WM). LPL associated with non-IgM monoclonal gammopathy or biclonal gammopathy is rarely observed. LPL diagnosis was based on clinical, morphological, and immunophenotypic findings. Recently, the test for L265P mutation of the myeloid differentiation factor 88 (MYD88) gene has been helpful in the diagnosis of LPL. Here, we reported the first case of LPL/WM with IgM-κ/IgA-λ biclonal gammopathy in Korea.

Evaluation of Time and Temperature Stability of Paroxysmal Nocturnal Hemoglobinuria Cells by Flow Cytometry

BACKGROUND: Flow cytometry analysis of paroxysmal nocturnal hemoglobinuria (PNH) is significantly affected by the methodology used. The lack of data on the effect of age and refrigeration on PNH clone stability motivated us to study these aspects using flow cytometry. METHODS: Peripheral blood was collected from six patients, of which two presented with PNH. All samples were tested immediately and stored at room temperature (RT, 20–25℃) and at 4℃ for re-analysis at 24, 48, 72 hr and 7 days. Anti-CD59-fluorescein isothiocyanate (Beckman Coulter, USA) and anti-CD235a-phycoerythrin (PE; Beckman Coulter) were used to stain red blood cells (RBCs). Fluorescein-labeled proaerolysin (Cedarlane, Canada), anti-CD15-PE (Beckman Coulter), anti-CD24-PE-cyanin 5 (Beckman Coulter), and anti-CD45-PE-cyanin 7 (Beckman Coulter) were used to stain granulocytes. Flow cytometry was performed using a FC500 flow cytometer (Beckman Coulter). The effects of time and temperature were analyzed using generalized estimating equations. RESULTS: No significant differences in the gated percentage of RBCs and PNH clone size of RBCs were observed between the RT and 4℃ groups up to 7 days of testing. The percentage of gated neutrophils decreased with specimen age (P<0.001) and a better correlation with baseline was obtained at 4℃ than at RT (P=0.014). Neutrophil PNH clones were stable until 48 hr and 72 hr at RT and 4℃, respectively, and could not be analyzed at 7 days. CONCLUSIONS: RBC analysis was successfully performed up to 7 days. For neutrophils, testing within 48 hr is recommended, because the number of gated cells decreases significantly with age.

Antimicrobial Activity of Medizyme-Plus, Developed for Cleansing Prior to Disinfection/Sterilization

OBJECTIVE: Disinfectants are essential for public health and environmental hygiene. The aim of this study was to investigate the in vitro antimicrobial activity of Medizyme-Plus (Soosan Co. Ltd., Seongnam, Korea) developed for cleansing prior to disinfection/ster-ilization, against bacteria and yeasts. METHODS: Clinical isolates were exposed to Medizyme-Plus (a product containing quaternary ammonium and a protease, amylase, and lipase) for various periods (0.5, 1, 2, 5, 10, 15, and 30 minutes). After exposure, the mixtures of isolates and Medizyme-Plus were inoculated into tryptic soy broths. To enumerate the surviving bacteria or yeasts, treated isolates were inoculated onto solid agar media (blood agar, MacConkey agar, and Sabouraud dextrose agar) and cultured at 35℃. RESULTS: All strains of bacteria and yeasts showed a 5-log10 reduction within 0.5 minutes of exposure to Medizyme-Plus. CONCLUSION: Medizyme-Plus can be used as a low-level disinfectant, in addition to cleanser, for hospital infection control. It will be necessary to perform disinfection/sterilization after cleansing with Medizyme-Plus.

Biocidal Effect of Hypochlorous Acid Solution, Neolox against Pathogenic Microorganisms

OBJECTIVE: Disinfection/sterilization of hospital devices prevents the occurrence of several infections; therefore, disinfectants are essential for public health. The purpose of this study was to evaluate the biocidal effect of a hypochlorous acid solution. METHODS: Hypochlorous acid solution, Neolox (Neo Chemical, Paju, Korea) obtained from Purester (Morinaga Engineering, Tokyo, Japan) was used. Antimicrobial activity of the solution against bacteria, yeasts, and mycobacteria at different exposure times (0.5, 1, 2, 5, 10, 15, and 30 minutes) was evaluated. RESULTS: All strains of bacteria and yeasts showed a 5-log10 reduction within 30 seconds of exposure to the solution, and mycobacteria showed the same reduction within 2 minutes. CONCLUSION: Hypochlorous acid solution has been widely used as a disinfectant in recent years. Neolox can be used as an effective intermediate- to high-level disinfectant for hospital infection control.

Annual Report on the External Quality Assessment Scheme for Biochemical Genetics in Korea (2015)

Two external quality assessment (EQA) trials of conventional newborn screening tests for phenylketonuria, galactosemia, congenital adrenal hyperplasia, maple syrup urine disease, homocystinuria, and congenital hypothyroidism, as well as newborn screening tests using tandem mass spectrometry, were performed in 2015. A total of 44 specimens in the form of dried blood spots were distributed to 16 laboratories and the response rate of these laboratories was 100%. The mean, standard deviation, coefficient of variation, median, and cut-offs were evaluated for each analyte in the newborn screening tests. Two EQA trials for the analyses of methylmalonic acid, vanillylmandelic acid, catecholamines, metanephrines, organic acids, and amino acids were also performed. A well-designed EQA program and continuous education would improve the performance of biochemical genetics tests.

De novo Leukemic Variant of Mast Cell Leukemia With KIT D816V

No abstract available.

Activities of Quality Improvement for Blood Culture at a University Hospital / 대한임상미생물학회지

BACKGROUND: Blood culture is a critical test for diagnosing bloodstream infections. Frequent microbial contamination during sampling and testing leads to abuse of antimicrobial agents. We evaluated methods for reducing contamination and obtaining more reliable results. METHODS: We analyzed blood cultures obtained between 2009 and 2015. We established 6 quality indicators: true positive rate, contamination rate, blood sampling volume, number of sets of blood cultures, delayed transportation rate, and percentage of samples collected from the femoral region, with reference to the CLSI guideline M47-A, 2007. Education was provided for interns and nurses responsible for blood sampling and transportation of specimens, and data were analyzed monthly. RESULTS: At baseline, the true positive rate was 12.8%, and the contamination rate was 4.0%. During the intervention period, these were decreased to 10.9% and 1.9%, respectively. The percentage of samples smaller than 5 mL decreased from 29.7% to 2.7-11.3%. The rate of one set of blood cultures being ordered was always <5%. The delayed transportation rate decreased from 35.6% to 5.5-7.7%. Finally, the percentage of samples collected from the femoral region decreased from 41.5% to 22.0-31.0%, because of which we did not attain our goal, 20.8%. CONCLUSION: The results showed improvements in contamination rate, specimen volume, specimen transportation time, and the percentage of samples collected from the femoral region. The quality management of blood cultures in 2011 was comparatively poor, which led to increased contamination rate, large number of samples containing <5 mL of blood, and increased percentage of samples collected from the femoral region. Thus, quality improvement methods can produce more reliable results of blood cultures.

Annual Report on the External Quality Assessment Scheme for Biochemical Genetics in Korea (2014)

Two trials of external quality assessment (EQA) of conventional newborn screening tests for phenylketonuria, galactosaemia, congenital adrenal hyperplasia, maple syrup urine disease, homocystinuria, and congenital hypothyroidism, as well as newborn screening tests were performed using tandem mass spectrometry in 2014. A total of 39 specimens in the form of dried blood spots were distributed to 16 laboratories and the response rate of these laboratories was 100%. Screening tests for phenylketonuria and congenital hypothyroidism did not meet the accepted performance criteria in some laboratories. The mean, standard deviation, coefficient of variation, median, and cut-offs were evaluated for each analyte in the newborn screening tests. Two trials of EQA for the analyses of methylmalonic acid, vanillylmandelic acid, catecholamines, metanephrines, organic acids, and amino acids were also performed. A well-designed EQA program and continuous education would improve the performance of biochemical genetic testing.

Evaluation of the OraQuick HCV Rapid Antibody Test as a Screening Test for Hepatitis C Virus Infection / 임상검사와정도관리

BACKGROUND: Among the multitude of tests developed for the diagnosis of hepatitis C virus (HCV) infection, the enzyme immunoassay and the chemiluminescence immunoassays (CLIA) are the most commonly used. The OraQuick HCV Rapid Antibody Test is also popular because it can detect HCV antibodies from blood or saliva within 20 minutes. In this study, we compared the performances of the OraQuick HCV Rapid Antibody Test and CLIA in the diagnosis of HCV infection. METHODS: We tested 150 serum samples from Soonchunhyang University Seoul Hospital for HCV between November 2012 and January 2013 using CLIA (ADVIA Centaur) as well as the OraQuick test. The data from both tests were compared to the results of HCV real-time PCR (COBAS AmpliPrep/COBAS TaqMan HCV test kit). RESULTS: In the PCR analysis, 59 of the 150 samples (39.3%) tested positive and 91 (60.7%) tested negative for HCV RNA. All these samples also tested positive when screened by CLIA. However, only 57 of 59 samples tested positive with the OraQuick test. Among the 91 samples found to be HCV-negative in the PCR analysis, 50 tested negative in both CLIA and the OraQuick tests. However, a discrepancy was noted among the remaining 41 samples that tested HCV-negative in the PCR analysis; 21 of these samples tested positive in both CLIA and the OraQuick tests, but the remaining 20 tested positive only in CLIA. CONCLUSIONS: Although the OraQuick test showed a marginally lower sensitivity for HCV detection than CLIA, we conclude that it is still beneficial because it is rapid and can be performed using blood and saliva samples. Our findings suggest that the OraQuick test could be an important diagnostic tool for screening HCV infection.

What Strategy Can be Applied to the Patients with Culture Positive Tuberculosis to Reduce Treatment Delay in a Private Tertiary Healthcare Center?

BACKGROUND: The contribution of the private sector to the treatment of tuberculosis (TB) is getting larger, and the private sector pays more attention to individualized, intensive care than patient monitoring or education, which would improve the microbiological cure rate or at least completion of treatment. We aim in this paper to assess the impact of the improved monitoring of patient on the treatment outcome in the private tertiary healthcare center. MATERIALS AND METHODS: We compared the data of the positive sputum cultures for TB from March 1, 2003 to March 31, 2006 (37 months) with that data from July 1, 2007 to August 31, 2008 (14 months) in single private tertiary healthcare center in the Republic of Korea (ROK). In the latter period, we notified physicians of the new culture-confirmed cases via a cellular phone short-massage-service (SMS) to prevent delayed recognition of positive cultures and we gave calls to patients to encourage treatment adherence and to complete the whole schedule of medication. RESULTS: After the intervention, initiation of anti-TB medication increased from 86.3% to 94.5% (P<0.05), the interval to medication from the first culture results was shortened from 22.9 days to 5.6 days (P=0.19) and the rate of treatment complication increased from 57.4% to 68.1% (P<0.01). CONCLUSION: Our results showed a possible strategy to improve the completion of treatment in a university hospital. Health care providers in the private sector should to improve success by better notification and monitoring in addition to their existing advanced medical resources.

Comparison of Ogawa Media, BACTEC MGIT 960 System and TB/NTM Real-Time PCR for Detecting Mycobacterium Species / 결핵및호흡기질환

BACKGROUND: Mycobacterial infection is a problem throughout the world along with the increase of immunocompromised patients. For this reason, there have been many methods for faster and more accurate diagnosis. In this study, we evaluated several laboratory methods for mycobacterial infection. METHODS: From January to December 2009, 635 specimens were cultured with mycobacteria growth indicator tube (MGIT) and Ogawa media. Polymerase chain reaction (PCR) was performed with the AdvanSure tuberculosis (TB)/non-tuberculosis mycobacterium (NTM) real-time PCR Kit (LG Life Sciences, Seoul, Korea). The 69 samples showing positive culture results were identified with the AdvanSure Mycobacteria Genotyping Chip Kit (LG Life Science, Seoul, Korea). RESULTS: Sixty-nine (10.9%) out of 635 samples showed positive results for mycobacterial culture. Among the 635 samples, 64 were positive in MGIT, but only 42 were positive in Ogawa media. Of the 635 samples, 607 (95.6%) showed the same results between MGIT and Ogawa and the results of 579 (95.4%) were also consistent with the TB/NTM real-time PCR results. However, in the case of NTM, only one (1/24, 4.2%) was positive in PCR. In the Mycobacteria genotyping chip analysis, the most frequently identified NTM species in descending order were M. avium, M. intracellulare, M. chelonae and M. abscessus. CONCLUSION: Culturing with a combination of MGIT and Ogawa is recommended to increase the recovery rate of mycobacteria. Although PCR missed a reasonable number of NTM, it is faster and usually gives results that concur with those from the culture. The appropriate combination of diagnostic methods with clinical correlation are necessary.

Analysis of Discarded Blood Components at a University Hospital in Korea / 대한수혈학회지

BACKGROUND: When it comes to wasting blood components, it usually means wastage before transfusion due to several reasons such as improvement of the patient's condition, death of the patient, delay of blood returning, etc. Yet blood components can sometimes can be wasted after a transfusion is started and this is referred as residual blood wastage. In this study, we analyzed the rate and causes of discarded blood components that are not used and the residual blood wastage in order to help reduce the rate of blood component wastage. METHODS: From January 2009 to December 2010, the number of and the reasons for discarded blood components without use and residual blood wastage were analyzed by reviewing the laboratory information system and wastage statements at Soonchunhyang University Seoul Hospital. RESULTS: The number of blood components issued during the study period was 24,001 units. Among them, the number of units discarded without use was 162 units (0.7%) and the number of units of residual blood wastage was 115 units (0.5%). Among the reasons for the discarded blood component without use, improvement of the patient's conditions ranked as 1st with 80 units (49.5%) and death of the patient ranked as 2nd with 42 units (25.9%). The biggest reason for the residual blood wastage was transfusion-related side effects with as many as 52 units (45.2%). Other than side effects, the wastage of residue from pediatric transfusion were 48 units (41.7%), followed by delay of surgery with 5 units (4.3%) and patients' refusal with 4 units (3.5%). CONCLUSION: The wastage of residue from pediatric transfusion was the second most common cause of residual blood wastage in our hospital. According to this, we should evaluate the routine use of pediatric transfusion bags and their cost-effectiveness in our hospital.

Identification of a Novel Mutation in the MCCC2 Gene of a Korean Patient with 3-Methylcrotonyl-CoA Carboxylase Deficiency

3-methylcrotonyl-CoA carboxylase deficiency is an autosomal recessive disorder characterized by a defect in leucine catabolism. We report the case of an 80-day-old patient with 3-methylcrotonyl-CoA carboxylase deficiency who had elevated levels of 3-hydroxyisovalerylcarnitine (45.56 micromol/L; reference range, C (p.Gly105Arg)] at nucleotide position 313 and a mutation caused by a heterozygous A to T transversion [c.1252A>T (p.lle418Phe)] at nucleotide position 1252. Identification of these 2 novel MCCC2 gene mutations in our patient suggested that analysis of the MCCC1 and MCCC2 genes might prove useful in the diagnosis of 3-methylcrotonyl-CoA carboxylase deficiency.

Comparison of SD BIOLINE Rapid Influenza Antigen Test Using Two Different Specimens, Nasopharyngeal Swabs and Nasopharyngeal Aspirates / 대한임상미생물학회지

BACKGROUND: The pandemic swine origin influenza A/H1N1 2009 virus (H1N1 2009) was rapidly spread out all over the world after it was first found in April, 2009. This study was made to compare the performance of nasopharyngeal swabs and nasopharyngeal aspirates for the SD Bioline rapid influenza antigen test. METHODS: From Aug to Nov, 2009 the SD Bioline rapid influenza antigen tests were conducted with the nasopharyngeal swabs and the nasopharyngeal aspirates from the 244 specimens of patients who had come to the hospital with influenza-like illness. The data from the examination were compared with the multiplex RT-PCR as a reference standard to obtain sensitivity, specificity, positive predictive value and negative predictive value. RESULTS: The sensitivity and the specificity of the SD Bioline rapid influenza antigen tests with the nasopharyngeal swabs were 75.8%, and 93.3% respectively, and the sensitivity and specificity with the nasopharyngeal aspirates were 61.3%, and 98.3% respectively. CONCLUSION: Even if the nasopharyngeal aspirates showed the lower sensitivity than the nasopharyngeal swabs, since the specificity is higher, the nasopharyngeal aspirates are more useful because we can reduce false positive rate.

A Case of Central Nervous System Myelomatosis with Complex Chromosome Aberrations / 대한진단검사의학회지

Involvement of the central nervous system is very uncommon in multiple myeloma, observed in approximately 1% of the multiple myeloma patients. We report a case of central nervous system myelomatosis with complex chromosome aberrations in a 62-yr-old female patient, who had previously been diagnosed as multiple myeloma. Fluorescent in situ hybridization revealed 13q deletion, p53 gene deletion and IGH/FGFR3 rearrangement and chromosomal study showed complex chromosome aberrations. After four cycles of chemotherapy, the patient was admitted to the hematology department with severe headache. Plasma cells were found in the cerebrospinal fluid (CSF), and CSF immunoelectrophoresis revealed abnormal precipitin arcs against anti-IgG and anti-lambda antisera. She was given systemic chemotherapy and eight courses of intrathecal chemotherapy, which cleared plasma cells in the CSF. Two months later, she was given autologous stem cell transplantation. Three months after stem cell transplantation, central nervous system myelomatosis progressed to plasma cell leukemia and two months later,the patient expired.

Needs for Hepatitis A Virus Immunization in Healthcare Personnel / 병원감염관리

BACKGROUND: Currently, the incidence of hepatitis A is on the increase in Korea. Although there is emphasis on contact precautions, the nosocomial outbreak of hepatitis A virus (HAV) in healthcare personnel has increased within endemic areas because these workers inevitably come in close contact with patients and work under suboptimal hygiene conditions. In this study, we evaluated the necessity of immunization against HAV for healthcare personnel. METHODS: We investigated the seropositivity of serum immunoglobulin G (IgG) anti-HAV antibody (Ab) in 672 healthcare personnel on the basis of their age-group, sex, and occupation in Soon Chun Hyang University Hospital and Soon Chun Hyang University Bucheon Hospital. RESULTS: The subjects were divided into 6 groups on the basis of their ages to identify differences among the various age groups in the number of cases with HAV Ab seropositivity. Significant intergroup differences were noted in this respect: 21-25 years, 2/152 (1.3%); 26-30 years, 33/245 (13.5%); 31-35 years, 70/148 (47.3%); 36-40 years, 52/79 (65.8%); >40 years, 44/48 (91.7%). CONCLUSION: The number of seropositive cases was low among young healthy personnel: low seropositivity is an emerging risk for vulnerable population. With the increase in the incidence of hepatitis A, healthcare personnel have become a risk population for hepatitis A, as are community residents. Therefore, for healthcare personnel working in hospitals, immunization against HAV should be recommended for personnel younger than 30 years, and serological testing for older personnel.

Experience of Use of the Automated Chemistry Analyzer Cobas(R) 6000 to Improve Work Flow of Emergency Chemistry Laboratory / 임상검사와정도관리

BACKGROUND: Soon Chun Hyang University Hospital emergency laboratory introduced Cobas(R) 6000 (Roche Diagnostics, Switzerland) to improve the turnaround time of emergency chemistry tests at peak time period. METHODS: For the designated period, before and after introduction of Cobas(R) 6000 the numbers of tests and test time were compared and we analyzed the process of the tests using Workflow simulator (Roche Diagnostics). RESULTS: The numbers of tests of 8 days (every Monday and Thursday) in June, 2007 and 2008 were 22,902 and 27,384. The mean test time of the 8 days in June, 2007 and 2008 were 13 min 41 sec and 12 min 22 sec. In 2007, increased mean test time was due to prolongation of waiting times in rotor within equipment for tests at peak time period. CONCLUSIONS: Using Cobas(R) 6000, the numbers of tests were increased at peak time period but mean test time was reduced, which made physicians and laboratory all satisfied.

Cutoff Value of 17-Hydroxyprogesterone Screening Test for Congenital Adrenal Hyperplasia According to Birth Weight / 임상검사와정도관리

BACKGROUND: False positive rate of 17-OHP screening test was higher more than other screening tests due to use same cutoff value both term and preterm infants in Korea. The purpose of this study is to set cutoff value of 17-OHP on the basis of birth weight in neonatal screening for congenital adrenal hyperplasia. METHODS: 17-OHP was measured in filter paper blood spots obtained by heel puncture between 3 and 7 days after birth. 17-OHP values were analyzed with respect to birth weight in order to decide the appropriate cutoff values in a neonatal screening for congenital adrenal hyperplasia. RESULTS: The mean concentrations of 17-OHP according to birth weight groups were as follows : 12.6, 7.0, 5.1, 3.7, 3.0, 2.5 ng/mL for birth weight of 1.50 or less, 1.50-1.99, 2.00-2.49, 2.50-2.99, 3.00-3.49, 3.50 kg or more, respectively. The cutoff values for determining the 17-OHP for recall were decided as follows : 55, 35, 18, 11, 8, 8 ng/mL for birth weight of 1.50 or less, 1.50-1.99, 2.00-2.49, 2.50-2.99, 3.00-3.49, 3.50 kg or more, respectively. Application of the new cutoff values according to birth weight dropped the total recall rate from 3.3% to 1.0%. CONCLUSIONS: The cutoff values of 17-OHP on the basis of birth weight should be used in the neonatal screening for congenital adrenal hyperplasia. We believe that the recall rate due to false positive can be reduced using this method in low birth weight infants.