scholarly journals Optimized procedures for testing plasma metanephrines in patients on hemodialysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christina Pamporaki ◽  
Aleksander Prejbisz ◽  
Robert Małecki ◽  
Frank Pistrosch ◽  
Mirko Peitzsch ◽  
...  

AbstractDiagnosis of pheochromocytomas and paragangliomas in patients receiving hemodialysis is troublesome. The aim of the study was to establish optimal conditions for blood sampling for mass spectrometric measurements of normetanephrine, metanephrine and 3-methoxytyramine in patients on hemodialysis and specific reference intervals for plasma metanephrines under the most optimal sampling conditions. Blood was sampled before and near the end of dialysis, including different sampling sites in 170 patients on hemodialysis. Plasma normetanephrine concentrations were lower (P < 0.0001) and metanephrine concentrations higher (P < 0.0001) in shunt than in venous blood, with no differences for 3-methoxytyramine. Normetanephrine, metanephrine and 3-methoxytyramine concentrations in shunt and venous blood were lower (P < 0.0001) near the end than before hemodialysis. Upper cut-offs for normetanephrine were 34% lower when the blood was drawn from the shunt and near the end of hemodialysis compared to blood drawn before hemodialysis. This study establishes optimal sampling conditions using blood from the dialysis shunt near the end of hemodialysis with optimal reference intervals for plasma metanephrines for the diagnosis of pheochromocytomas/paragangliomas among patients on hemodialysis.

2021 ◽  
Author(s):  
Christina Pamporaki ◽  
Aleksander Prejbisz ◽  
Robert Małecki ◽  
Frank Pistrosch ◽  
Mirko Peitzsch ◽  
...  

Abstract Background Diagnosis of pheochromocytomas and paragangliomas in patients receiving hemodialysis is troublesome. Aim To establish optimal conditions for blood sampling for mass spectrometric measurements of normetanephrine, metanephrine and 3-methoxytyramine in patients on hemodialysis and specific reference intervals for plasma metanephrines under the most optimal sampling conditions. Methods Blood was sampled before and near the end of dialysis, including different sampling sites in 170 patients on hemodialysis. Results Plasma normetanephrine concentrations were lower (P < 0.0001) and metanephrine concentrations higher (P < 0.0001) in shunt than in venous blood, with no differences for 3-methyxytyramine. Normetanephrine, metanephrine and 3-methoxytyramine concentrations in shunt and venous blood were lower (P < 0.0001) near the end than before hemodialysis. Upper cut-offs for normetanephrine were 34% lower when the blood was drawn from the shunt and near the end of hemodialysis compared to blood drawn before hemodialysis. Conclusion This study establishes optimal sampling conditions using blood from the dialysis shunt near the end of hemodialysis with optimal reference intervals for plasma metanephrines for the diagnosis of pheochromocytomas/paragangliomas among patients on hemodialysis.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 22-23
Author(s):  
Mohamed A Yassin ◽  
Ashraf Tawfiq Soliman ◽  
Feryal Abbas ◽  
Abdulqadir Jeprel Nashwan ◽  
Mahmood B Aldapt ◽  
...  

Introduction: The majority of physicians' medical judgments are based on clinical information supported by laboratory reports . The availability of a reference interval for different lab values facilitates the process of interpretation . Complete blood count (CBC), testing is one of the most frequently performed hematology test in any clinical setting. Analysis of CBC by hematology analyzers is an indispensable means in the evaluation of many acute and chronic disorders including traumatic, infectious, immunological, and hematological diseases. Establishment of a normal reference interval is essential for accurate clarification of the disease diagnosis as well as for follow up. CBC techniques have improved significantly, and the accurate automated methods have now substituted manual methods. In addition, various novel blood cell parameters have been developed alongside to aid in diagnosis and management of several blood disorders . However significant differences exist in the reference intervals based on age, gender, ethnicity, genetic differences, environmental factors, and geographical location.. Dietary habits and occupational exposures are factors that have been shown to affect reference interval . Therefore, there is a requirement for each country to establish its own reference intervals. Country-specific reference intervals for CBC of adult peripheral blood have been established in many countries around the world; however, there have been no specific comprehensive studies in Arab population in Qatar based on age, gender, geographic location and ABO blood groups. To the best of our knowledge, this is the first study in Qatar that investigated CBC reference intervals in relation to age, gender, and blood grouping which can now be used as a reference when evaluating patient samples in Qatar. Methods: Venous blood specimens were collected from 720 healthy randomly selected individuals aged 18 to 69 years from 2018 to 2019 and analyzed by Sysmex NX-10 and NX -20 automated hematology analyzers. Results were statistically analyzed and compared by gender, age, and ABO blood group. Arab adults were divided into African Arabs (Egypt, Libya, Tunisia, Morocco) and Asian Arabs (Syria, Lebanon, Jordon, Palestine, Qatar). The lower and upper reference limits of the hematology reference intervals were established at the -2 SD and +2SD respectively. Results: Reference intervals were calculated for all the hematology parameters which included red blood cell, white blood cell and differential count, and platelet parameters. Arab males had significantly higher Hb, Hct, RDW, ANC, lymphocytes and monocyte counts compared to adult females. Asian-Arab males had significantly higher Hb concentration and higher WBC, lymphocytes and eosinophil counts compared to African- Arab males. Asian Arab young males had significantly higher Hb level and lymphocyte count and lower monocytes counts compared old males. African Arab young males had significantly higher lymphocyte and lower monocytes counts compared to old males. Asian- Arab young females had higher WBC, ANC counts compared to old Asian Arab females. No statistical difference in the studied hematological parameters was detected among the three groups with different ABO subgroups Conclusions: Data from this study established specific reference intervals which could be considered for general use in the Arab world. The differences in hematology reference intervals in respect to age, sex and geographical location highlights the necessity to establish reference intervals for venous blood parameters among the healthy population in each country or at least in each region. Disclosures No relevant conflicts of interest to declare.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Esra Fırat Oğuz ◽  
Mesude Falay ◽  
Müjgan Ercan Karadağ ◽  
Esma Andaç Uzdoğan ◽  
Emiş Deniz Akbulut ◽  
...  

Abstract Objectives Recent advances in hematology analyzers have enabled to improve the reliability in the results and also provided additional hematological parameters. In the present study, we aimed to determine the reference ranges for automated erythrocyte and reticulocyte parameters in healthy individuals on Sysmex XN 1000 hematology analyzer. Methods One hundred and thirty-three subjects with normal physical examination and complete blood count results within the reference ranges were included in the study. Venous blood samples collected in tubes containing K2-EDTA were analyzed on Sysmex XN-1000. The references intervals for IRF, RBC He, Ret He, LFR, MFR, HFR, Delta He, Micro R, Macro R, Hypo He and Hyper He were determined according to CLSI EP28-A3c. Results The reference ranges of the parameters were estimated with 90% confidence intervals. The reference ranges were 3.4–17% for IRF, 26.9–32.8 pg for Ret-He, 25.2–30.5 pg for RBC-He and 0.5–3.7 pg for delta-He. Gender specific reference ranges were calculated for of Ret-He (male (M): 26.8–32.9 pg, female (F): 23.9–33.6 pg), RBC-He (M: 26.3–30.8 pg, F: 25.3–30.5 pg) and delta-He (M: 0.5–3.7 pg, F: 0.3–3.7 pg). Conclusions The new reticulocyte and erythrocyte parameters may be conveniently used in clinical diagnosis and follow-up of patients, as they offer reliable, automated and cheap results. Each laboratory is recommended to determine its own reference intervals considering the differences like the instrument used and population studied.


2000 ◽  
Vol 34 (21) ◽  
pp. 4496-4503 ◽  
Author(s):  
Ian W. Croudace ◽  
Phillip E. Warwick ◽  
Rex N. Taylor ◽  
Andrew B. Cundy

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 982.1-982
Author(s):  
S. A. Just ◽  
P. Toftegaard ◽  
U. Jakobsen ◽  
T. R. Larsen

Background:Regular blood sampling is a requirement for rheumatological patients receiving csDMARD, bDMARD or tsDMARD therapies (1). The frequent blood sampling affects the patient’s life as they use a substantial amount of time at hospitals or by the general practitioner. Often visits are time-consuming with transport, waiting time, and for some patient’s costly long travels. Giving patients the option of taking the blood samples themself in their own home, as part of a patient-centred monitoring approach, could provide the patient much higher degree of independence. Further, it may increase the quality of life, cause higher compliance with taking the control samples and possibly reduce health care costs.Objectives:1. To investigate if rheumatological patients can take capillary blood samples and describe patient-reported outcomes (PRO) about the procedure. 2. Compare the venous and capillary samples’ results. 3. Test if the laboratory automated analysis equipment can handle the small capillary samples.Methods:21 rheumatological patients, underwent capillary and venous blood sampling at up to 4 occasions (1-2 months between). Instructions were available on a pictogram. PRO data were assessed by questionnaires. The patient performed blood extraction to the capillary samples from a finger after using a device making a small incision (2 mm depth and 3 mm width). Two capillary tubes (one Microtainer K2-EDTA and one Microtainer lithium heparin with gel) were filled with a total volume of approximately 1.0 mL blood. A phlebotomist took the venous sample. Blood samples were analyzed for alanine aminotransferase (ALAT), albumin, alkaline phosphatase (ALP), calcium, C-reactive protein (CRP), creatinine, potassium, lactate dehydrogenase (LDH), urate, hemolysis index, erythrocyte corpuscular volume (MCV), haemoglobin, leukocytes, differential count and platelets.Results:A total of 53 paired capillary (C) and venous (V) samples were taken. The average perceived pain of the procedure of C sampling was VAS: 10.3 (SD:14.4) (0-100) versus V sampling VAS: 8.5 (SD:11.7). 90% of patients would accept it as a future form of blood sampling.Differences in blood samples (C versus V) were: CRP (-3.4%); Hemoglobin (-1.4%); Creatinine (-4.4%), ALAT (-2.9%), neutrophils (1.43%), platelets (-16.9%).The index of hemolysis was on average 128.9 mg/dL (SD: 203) in C versus 6.7 mg/dL (SD: 4.6) in V. Results was evaluated by a rheumatologist, and 92.5% of capillary samples could be used to evaluate the safety of DMARD treatment based on the most critical samples for this: ALAT, creatinine, neutrophils and platelets (1). The 7.5 % not accepted were all due to aggregated platelets leading to low platelet count. There was hemolysis in 18% of the samples, but the analysis results could be used despite this.Conclusion:In the majority of rheumatological patients, capillary self-sampling is well tolerated.We show that it is possible to extract the needed results from the capillary samples to evaluate DMARD treatment safety, despite higher hemolysis index. Using capillary samples taken at home could be a central instrument in future rheumatological patient-centred monitoring.References:[1]Rigby WFC et al. Review of Routine Laboratory Monitoring for Patients with Rheumatoid Arthritis Receiving Biologic or Nonbiologic DMARDs. Int J Rheumatol. 2017Disclosure of Interests:None declared


Author(s):  
O E Okosieme ◽  
Medha Agrawal ◽  
Danyal Usman ◽  
Carol Evans

Background: Gestational TSH and FT4 reference intervals may differ according to assay method but the extent of variation is unclear and has not been systematically evaluated. We conducted a systematic review of published studies on TSH and FT4 reference intervals in pregnancy. Our aim was to quantify method-related differences in gestation reference intervals, across four commonly used assay methods, Abbott, Beckman, Roche, and Siemens. Methods: We searched the literature for relevant studies, published between January 2000 and December 2020, in healthy pregnant women without thyroid antibodies or disease. For each study, we extracted trimester-specific reference intervals (2.5–97.5 percentiles) for TSH and FT4 as well as the manufacturer provided reference interval for the corresponding non-pregnant population. Results: TSH reference intervals showed a wide range of study-to-study differences with upper limits ranging from 2.33 to 8.30 mU/L. FT4 lower limits ranged from 4.40–13.93 pmol/L, with consistently lower reference intervals observed with the Beckman method. Differences between non-pregnant and first trimester reference intervals were highly variable, and for most studies the TSH upper limit in the first trimester could not be predicted or extrapolated from non-pregnant values. Conclusions: Our study confirms significant intra and inter-method disparities in gestational thyroid hormone reference intervals. The relationship between pregnant and non-pregnant values is inconsistent and does not support the existing practice in some laboratories of extrapolating gestation references from non-pregnant values. Laboratories should invest in deriving method-specific gestation reference intervals for their population.


2021 ◽  
Author(s):  
K Aaron Geno ◽  
Matthew S Reed ◽  
Mark A Cervinski ◽  
Robert D Nerenz

Abstract Introduction Automated free thyroxine (FT4) immunoassays are widely available, but professional guidelines discourage their use in pregnant women due to theoretical under-recoveries attributed to increased thyroid hormone binding capacity and instead advocate the use of total T4 (TT4) or free thyroxine index (FTI). The impact of this recommendation on the classification of thyroid status in apparently euthyroid pregnant patients was evaluated. Methods After excluding specimens with thyroid autoantibody concentrations above reference limits, thyroid-stimulating hormone (TSH), FT4, TT4, and T-uptake were measured on the Roche Cobas® platform in remnant clinical specimens from at least 147 nonpregnant women of childbearing age and pregnant women at each trimester. Split-sample comparisons of FT4 as measured by the Cobas and equilibrium dialysis were performed. Results FT4 decreased with advancing gestational age by both immunoassay and equilibrium dialysis. TSH declined during the first trimester, remained constant in the second, and increased throughout the third, peaking just before delivery. Interpretation of TT4 concentrations using 1.5-times the nonpregnant reference interval classified 13.6% of first trimester specimens below the lower reference limit despite TSH concentrations within trimester-specific reference intervals. Five FTI results from 480 pregnant individuals (about 1.0%) fell outside the manufacturer’s reference interval. Conclusions Indirect FT4 immunoassay results interpreted in the context of trimester-specific reference intervals provide a practical and viable alternative to TT4 or FTI. Declining FT4 and increasing TSH concentrations near term suggest that declining FT4 is not an analytical artifact but represents a true physiological change in preparation for labor and delivery.


Sign in / Sign up

Export Citation Format

Share Document