ABSTRACT
Multiple Myeloma is a myeloproliferative disorder of plasma cells, which may be complicated with secondary amyloidosis. We report a 48 year old woman consulting to primary care for weight loss and malaise. An initial laboratory study revealed a hypogammaglobulinemia with a monoclonal component and lambda light chains. These results motivated her derivation to hematology: her serum calcium was 11.8 mg/dl, immunofluorescence showed a monoclonal component of lambda chains and urine Bence-Jones protein was positive. A bone marrow biopsy confirmed plasma cell infiltration. A Congo-red stain of a rectal biopsy was positive. The patient was treated with thalidomide, bortezomid and dexamethasone.
Subject(s)
Amyloidosis/diagnosis , Multiple Myeloma/diagnosis , Amyloidosis/complications , Amyloidosis/drug therapy , Biopsy , Early Diagnosis , Family Health , Female , Humans , Immunoglobulin lambda-Chains/blood , Middle Aged , Multiple Myeloma/complications , Multiple Myeloma/drug therapy , Primary Health Care , Treatment OutcomeABSTRACT
BACKGROUND: International recommendations highlight the superior value of cardiac troponins (cTns) for early diagnosis of myocardial infarction along with analytical requirements of improved precision and detectability. In this multicenter study, we investigated the analytical performance of a new high sensitive cardiac troponin I (hs-cTnI) assay and its 99th percentile upper reference limit (URL). METHODS: Laboratories from nine European countries evaluated the ARCHITECT STAT high sensitive troponin I (hs-TnI) immunoassay on the ARCHITECT i2000SR/i1000SR immunoanalyzers. Imprecision, limit of blank (LoB), limit of detection (LoD), limit of quantitation (LoQ) linearity of dilution, interferences, sample type, method comparisons, and 99th percentile URLs were evaluated in this study. RESULTS: Total imprecision of 3.3%-8.9%, 2.0%-3.5% and 1.5%-5.2% was determined for the low, medium and high controls, respectively. The lowest cTnI concentration corresponding to a total CV of 10% was 5.6 ng/L. Common interferences, sample dilution and carryover did not affect the hs-cTnI results. Slight, but statistically significant, differences with sample type were found. Concordance between the investigated hs-cTnI assay and contemporary cTnI assay at 99th percentile cut-off was found to be 95%. TnI was detectable in 75% and 57% of the apparently healthy population using the lower (1.1 ng/L) and upper (1.9 ng/L) limit of the LoD range provided by the ARCHITECT STAT hs-TnI package insert, respectively. The 99th percentile values were gender dependent. CONCLUSIONS: The new ARCHITECT STAT hs-TnI assay with improved analytical features meets the criteria of high sensitive Tn test and will be a valuable diagnostic tool.
Subject(s)
Immunoassay , Troponin I/blood , Adolescent , Adult , Aged , Aged, 80 and over , Blood Coagulation Tests/instrumentation , Europe , Female , Humans , Laboratories , Male , Middle Aged , Reagent Kits, Diagnostic , Sensitivity and Specificity , Young AdultABSTRACT
Graves' disease (GD) is the most common cause of hyperthyroidism in iodine-replete populations. It is an autoimmune disease caused by autoantibodies to the TSHR (TRAb). Although the diagnostic is mainly clinical, measuring TRAb improves accuracy and provides valuable prognostic information. The aim of this study was to compare the performance of two of the most widely used immunoassays i.e., EliA™ anti-TSH-R and Elecsys® anti-TSH-R. We have carried out a comparative study measuring TRAb by the two immunoassays in consecutive sera samples referred to the laboratory for TRAb measurement. Autoantibodies were measured in all samples in parallel by the two techniques. The two techniques were highly concordant as demonstrated by a Cohen's kappa of 0.82. At the manufacturer recommended cut-off, sensitivity of Elecsys® TRAb test was higher (100% vs. 96.6%), while specificity of the EliA™ TRAb test was higher (99.4% vs. 95.3%). In most patients TRAb are detected by any of two tests which are both well suited for Clinical Laboratories use. However, a higher specificity may constitute an advantage for measurement used not for screening but for diagnostic purposes, as anti-TSH-R is.
Subject(s)
Graves Disease , Laboratories, Clinical , Autoantibodies , Humans , Immunoassay/methods , Receptors, ThyrotropinABSTRACT
Multiple Myeloma is a myeloproliferative disorder of plasma cells, which may be complicated with secondary amyloidosis. We report a 48 year old woman consulting to primary care for weight loss and malaise. An initial laboratory study revealed a hypogammaglobulinemia with a monoclonal component and lambda light chains. These results motivated her derivation to hematology: her serum calcium was 11.8 mg/dl, immunofluorescence showed a monoclonal component of lambda chains and urine Bence-Jones protein was positive. A bone marrow biopsy confirmed plasma cell infiltration. A Congo-red stain of a rectal biopsy was positive. The patient was treated with thalidomide, bortezomid and dexamethasone.