scholarly journals Falsely markedly elevated 25-hydroxyvitamin D in patients with monoclonal gammopathies

Author(s):  
Helle Borgstrøm Hager ◽  
Nils Bolstad ◽  
David J. Warren ◽  
Marianne Vindal Ness ◽  
Birgitte Seierstad ◽  
...  

AbstractObjectivesMonoclonal immunoglobulins can cause interference in many laboratory analyses. During a 4 month period we observed seven patients with monoclonal disease and falsely extremely elevated 25-hydroxyvitamin D (25(OH)D) results above 160 ng/mL (>400 nmol/L) measured using an immunoassay from Abbott Diagnostics. Based on these findings, we studied the occurrence of falsely elevated 25(OH)D in samples with paraproteins and investigated possible mechanisms of the observed interference.Methods25(OH)D was analyzed using the Architect i2000 platform from Abbott Diagnostics and a higher order method, liquid chromatography-mass spectrometry (LC-MS/MS), in serum samples from 50 patients with known monoclonal disease. Patients with falsely elevated 25(OH)D were included in further studies to elucidate the cause of interference. Spuriously elevated results were in addition analyzed on two alternative platforms (Siemens and Roche).ResultsFalsely elevated 25(OH)D levels were present in eight patients on the Abbott analyzer and one on the Siemens platform. Results from Roche were comparable with LC-MS/MS. Additional investigations excluded elevated concentrations of rheumatoid factor and heterophilic antibodies as the cause of interference in the Abbott assay.ConclusionsLaboratories should be aware of the risk of falsely elevated 25(OH)D in samples run on the Architect analyzer from patients with monoclonal disease. Highly elevated vitamin D results should be diluted and if the dilution is non-linear, rerun by a different method, preferably LC-MS/MS. In patients with spuriously elevated 25(OH)D without known monoclonal disease, the laboratory should consider requesting protein electrophoresis to exclude paraprotein interference.

2009 ◽  
Vol 15 (11) ◽  
pp. 1280-1285 ◽  
Author(s):  
Trygve Holmøy ◽  
Stine Marit Moen ◽  
Thomas A Gundersen ◽  
Michael F Holick ◽  
Enrico Fainardi ◽  
...  

Hypovitaminosis D may play a role in multiple sclerosis (MS), but little is known about intrathecal vitamin D. 25-Hydroxyvitamin D was measured in cerebrospinal fluid and sera from 36 patients with relapsing-remitting MS, 20 patients with other inflammatory neurological diseases and 18 patients with non-inflammatory neurological diseases with liquid chromatography-mass spectrometry. There were no significant differences in cerebrospinal fluid concentrations of 25-hydroxyvitamin D, but the cerebrospinal fluid:serum ratio was significantly lower in MS compared with other inflammatory neurological diseases (p=0.0012) and non-inflammatory neurological diseases (p=0.041) patients. The concentrations of 25-hydroxyvitamin D in cerebrospinal fluid and serum were positively correlated and their ratio was similar to that of albumin. Neither the concentrations of 25-hydroxyvitamin D in cerebrospinal fluid or serum nor their ratio were associated with the presence of relapses or gadolinium-enhanced lesions. These results do not support that 25-hydroxyvitamin D is actively transported to the cerebrospinal fluid, or that the cerebrospinal fluid or serum levels or their ratio exert a major impact on MS activity.


Author(s):  
Sung E Cho ◽  
Sollip Kim ◽  
Young D Kim ◽  
Hyojung Lee ◽  
Dong H Seo ◽  
...  

Background We evaluated the performance of ultra-performance liquid chromatography-tandem mass spectrometry to measure serum 3-epi-25-hydroxyvitamin D3, 25-hydroxyvitamin D3 and 25-hydroxyvitamin D2 concentrations in 519 infant, paediatric and adolescent serum samples in Korea. Methods We used a Kinetex XB-C18 column and isocratic methanol/water (77.5/22.5, v/v) with 0.025% (v/v) high-performance liquid chromatography solvent additive flowing at 0.25 mL/min, yielding an 11 min/sample run time. A TQD triple quadrupole mass spectrometer in electrospray ionization positive ion mode with multiple reaction monitoring transition via an MSMS vitamin D kit was used to evaluate precision, carryover, ion suppression and linearity. Samples were prepared using the 4-phenyl-1,2,4-triazoline-3,5-dione derivatization method. Results Intra- and inter-run precisions were 1.23–13.28% and 1.02–10.08%, respectively. Group carryovers were −0.27% and 0.10%, respectively. There was no ion suppression. The calibration curve showed good linearity from calibrator Level 1 (11.75 nmol/L) to 6 (375 nmol/L) with R2 > 0.9999. The 3-epi-25-hydroxyvitamin D3 and 25-hydroxyvitamin D3 peaks were clearly separated in the extracted ion chromatogram. Infant serum samples 3-epi-25-hydroxyvitamin D3 concentrations were significantly higher than paediatric and adolescent concentrations. Conclusions The ultra-performance liquid chromatography-tandem mass spectrometry assay performed acceptably, clearly separating 3-epi-25-hydroxyvitamin D3 from 25-hydroxyvitamin D3. High 3-epi-25-hydroxyvitamin D3 concentrations were observed in infant but not in paediatric and adolescent serum samples.


Nutrients ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1714
Author(s):  
Habiba AlSafar ◽  
William B. Grant ◽  
Rafiq Hijazi ◽  
Maimunah Uddin ◽  
Nawal Alkaabi ◽  
...  

Insufficient blood levels of the neurohormone vitamin D are associated with increased risk of COVID-19 severity and mortality. Despite the global rollout of vaccinations and promising preliminary results, the focus remains on additional preventive measures to manage COVID-19. Results conflict on vitamin D’s plausible role in preventing and treating COVID-19. We examined the relation between vitamin D status and COVID-19 severity and mortality among the multiethnic population of the United Arab Emirates. Our observational study used data for 522 participants who tested positive for SARS-CoV-2 at one of the main hospitals in Abu Dhabi and Dubai. Only 464 of those patients were included for data analysis. Demographic and clinical data were retrospectively analyzed. Serum samples immediately drawn at the first hospital visit were used to measure serum 25-hydroxyvitamin D [25(OH)D] concentrations through automated electrochemiluminescence. Levels < 12 ng/mL were significantly associated with higher risk of severe COVID-19 infection and of death. Age was the only other independent risk factor, whereas comorbidities and smoking did not contribute to the outcomes upon adjustment. Sex of patients was not an important predictor for severity or death. Our study is the first conducted in the UAE to measure 25(OH)D levels in SARS-CoV-2-positive patients and confirm the association of levels < 12 ng/mL with COVID-19 severity and mortality.


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