Laboratory medicine最新文献

Introduction: Severe acute pancreatitis is a life-threatening condition characterized by systemic inflammatory response syndrome and an increased risk of complications such as venous thrombosis, all of which contributes to a high mortality rate. Heparin resistance, although rare, can lead to ineffective anticoagulation and thrombus formation during unfractionated heparin therapy, complicating management.

Methods: We report a case of heparin resistance in which, despite increasing the unfractionated heparin dosage, the patient's activated partial thromboplastin time remained subtherapeutic.

Results: Laboratory findings indicated normal antithrombin levels but undetectable anti-Xa activity, confirming non-antithrombin-mediated heparin resistance. A multidisciplinary approach led to the successful management of thrombosis with rivaroxaban, resulting in substantial clinical improvement.

Discussion: This case highlights the importance of early recognition and management of heparin resistance in patients with severe acute pancreatitis. Combined monitoring of activated partial thromboplastin time and anti-Xa activity is crucial for optimizing anticoagulation therapy and preventing complications such as deep vein thrombosis.

Introduction: Iron-deficiency anemia (IDA) and non-transfusion-dependent thalassemia (NTDT) are the 2 most common types of microcytic hypochromic anemia, but they are difficult to distinguish by routine tests. It is reported that red blood cells (RBCs) in thalassemia tend to be more microcytic and polymorphic, which may interfere with impedance platelet count (PLT-I). To correct PLT-I, fluorescence platelet count (PLT-F) can be used.

Methods: To establish a new discriminant formula based on the discrepancy between PLT-I and PLT-F (dPLT), this study retrospectively reviewed 350 patients: 145 with IDA and 205 with NTDT. The RBC and platelet parameters were obtained on a Sysmex XN-9000 system. Univariable and multivariable regression analyses were performed to screen the indicators. Diagnostic efficacy was analyzed using receiver operating characteristic curves.

Results: We found that the interference with PLT-I by RBCs was greater in patients with NTDT. The dPLT of patients with NTDT was statistically significantly higher than that of patients with IDA. Based on erythrocyte indices and dPLT, the diagnosis model, called PRMH (a model incorporating platelet difference, RBC count, mean corpuscular hemoglobin concentration, and hematocrit), was established.

Discussion: When compared with 11 reported formulas, the PRMH model showed better diagnostic efficacy, with a sensitivity of 88% and a specificity of 87%. Hence, the PRMH model can be used to distinguish NTDT from IDA.

Introduction: The antiretroviral regime emtricitabine-tenofovir disoproxil fumarate (Truvada [Gilead Sciences]) is a type of pre-exposure prophylaxis (PrEP) therapy used for the prevention and management of HIV infections. This protection, however, cannot be applied to other sexually transmitted infections (STIs), with many studies observing an increase in STI rates among individuals using PrEP.

Methods: A 24-year-old man who had recently started PrEP with emtricitabine-tenofovir disoproxil fumarate was found to have a clinically significant elevation in syphilis total antibody count on STI screening, but his rapid plasma reagin (RPR) and Treponema pallidum particle agglutination (TP-PA) results remained negative. The patient was subsequently treated for a syphilis infection.

Results: Post-treatment testing showed a negative syphilis total antibody result. The patient was suspected to have undergone treponemal antibody seroreversion, a rare but previously documented phenomenon following successful treatment.

Discussion: This case highlights the possible effect of PrEP on the immune system, requiring closer surveillance to prevent acquisition of other STIs.

Introduction: A questionnaire was sent to immunology laboratories worldwide by the European Organisation for External Quality Assurance Providers in Laboratory Medicine to evaluate current practice with regard to how antinuclear antibodies (ANAs) are routinely tested in clinical laboratories.

Methods: In total, 494 questionnaires were returned from 44 countries. Of these, 379 provided sufficient information to be included in the analysis.

Results: Indirect immunofluorescence on HEp-2 cells is still the most common method to test ANAs and is used by 330 of our 379 respondents. The most common (60%) screening dilution is 1:80, followed by 1:160 (15%) and, in equal amounts, 1:40 and 1:100 (8% each). In most laboratories, ANA-positive samples are further diluted to an end titer of 1:1280 (40%), 1:2560 (21%), 1:5120 (16%), or 1:640 (19%). An increasing number of laboratories (178/330) use the International Consensus on ANA Patterns (ICAP) nomenclature to describe the immunofluorescence pattern on HEp-2 cells. In countries with the most respondents, the percentage of laboratories accredited to EN International Organization for Standardization (ISO) 15189 (in Britain, BS EN ISO 15189, which is a British standard as well as a European standard as well as an ISO standard with identical content) is between 8% (Belgium) and 60% (France). There was no difference in the portion of accredited laboratories between university hospitals, nonuniversity hospitals, and private laboratories.

Discussion: Indirect immunofluorescence continues to be the most frequently used technique for ANA testing in laboratories. The increasing number of laboratories using the ICAP classification reflects an ongoing harmonization of describing ANA patterns on HEp-2 cell substrates.

Introduction: Duchenne muscular dystrophy (DMD) is a severe genetic disorder affecting 5% to 19% of carriers. Creatine kinase (CK) is a traditional biomarker for DMD, but its screening accuracy is limited. This study evaluated the potential of combining the proto-oncogene tyrosine-protein kinase receptor Ret (RET) with CK-MM to enhance screening efficacy.

Methods: Creatine kinase-MM and RET levels were analyzed in 14 adult and 5 newborn carriers of DMD, along with noncarrier control individuals. The CK-MM/RET ratio was calculated, and a receiver operating characteristic curve analysis evaluated biomarker screening efficiency. Methods for extracting RET from dried blood spots (DBSs) were compared with correlations between DBSs and serum RET levels and stability under varying storage conditions.

Results: Carriers of DMD exhibited elevated CK-MM and CK-MM/RET ratios with reduced RET. The CK-MM/RET ratio had the highest screening efficiency. Extraction of RET was optimal using Diluent C at 4 °C overnight, showing a strong DBS-serum correlation; RET remained stable, except under high humidity and temperature conditions.

Discussion: Combining RET with CK-MM enhances DMD carrier screening, offering a more efficient DBS-based method for early detection.

Introduction: Cold-reacting antibodies that bind to and trigger premature erythrocyte destruction are present in patients with cold autoimmune hemolytic anemia (cAIHA). The diagnosis of cAIHA is challenging because of the rarity of the disease, especially in patients with nonspecific features.

Methods: In this case report, we discuss an unusual case of cAIHA in an older man who presented with asymptomatic hyperkalemia, highlighting the hematologic and biochemical changes associated with the disease.

Results: Although hyperkalemia is expected with in vivo hemolysis because of autoantibody-mediated destruction of red blood cells, pseudohyperkalemia caused by in vitro hemolysis was also detected. The combination of actual in vivo hyperkalemia and pseudohyperkalemia resulted in a measured potassium value that was higher than the in vivo potassium concentration.

Discussion: It is pertinent to consider both in vivo and in vitro hemolysis in patients with cAIHA, particularly when assessing potassium status, so that an appropriate intervention can be administered for better patient outcomes.

Introduction: About one-third of multiple myelomas produce excess free monoclonal light chains. Detection of monoclonal light chains is important for diagnosis, prognosis, and monitoring of such lesions. A previously described method for detection of monoclonal light chains in serum required multiple manual wash steps. Even though the method has sensitivity similar to that of mass spectrometry, the manual wash steps were a hindrance to the method's widespread use.

Methods: To mitigate the laborious nature of the previous method, the SPIFE Nexus instrument (Helena Laboratories) was modified to automate the sample application, electrophoretic separation, antibody application, washing and blotting steps needed for removal of background proteins. Background noise was mitigated by modifying the wash buffer by adding a detergent. This revised automated electrophoresis protocol was tested in parallel with the previously described method.

Results: The sensitivity and specificity of the modified method using antisera to free light chains from 2 sources was comparable to the parameters of the previously described method without the need for manual manipulation.

Discussion: The automated protocol employing the SPIFE Nexus instrument and incorporating antisera to free light chains is suitable for routine use in clinical laboratories in an automated, enhanced-sensitivity assay for monoclonal light chains with no need for manual manipulation.

Introduction: We sought to compare clinical features among distinct antibody profiles defined by the presence or absence of antinucleosome (anti-NCS) and anti-double-stranded DNA (anti-dsDNA) antibodies in Tunisian patients with systemic lupus erythematosus (SLE).

Methods: The study enrolled 131 patients with SLE meeting at least 4 American College of Rheumatology or SLICC criteria. Participants were recruited from the Department of Internal Medicine and Rheumatology at the university teaching hospital of Monastir between January 2000 and December 2022. The patients were divided into 4 groups: Group 1 with neither anti-dsDNA nor anti-NCS; Group 2 with anti-dsDNA and no anti-NCS; Group 3 with anti-NCS lacking anti-dsDNA; and Group 4 with both anti-NCS and anti-dsDNA.

Results: The mean (SD) age at the time of diagnosis for the 131 participants with SLE was 38.7 (15.1) years; the ratio of female to male individuals was 7.2. Thirty-four (26%) patients were positive for anti-NCS and anti-dsDNA (group 4: antinuclear antibody pattern AC-1, 72%; pattern AC-5, 16%), and 30 (22.9%) were positive for anti-NCS and negative for anti-dsDNA (group3: pattern AC-1, 53.6%; pattern AC-5, 32.1%). The group 3 patients showed higher peripheral neuropsychiatric SLE (P =.034) and lower rates of disease activity (P =.01). The comparison between the 4 groups showed that group 4 patients had the highest frequency of lupus nephritis (P ≤.001) and the highest rate disease activity (P =.013).

Discussion: Patients with both anti-NCS and anti-dsDNA at the time of diagnosis are likely to have severe SLE, while anti-NCS was associated with nonsevere disease in patients with SLE who lack anti-dsDNA.

Introduction: Blood transfusions are routinely performed in operation rooms. The process chain of performing ABO type, antibody screen, crossmatch, blood transport, and patient verification is complex. A multidisciplinary task force convened to improve the process of blood ordering and utilization identified 3 issues: (1) blood orders performed on paper included transcription errors; (2) guidelines for blood ordering practices were lacking, with inappropriate and arbitrary requests; and (3) there were long intervals between ordering and receiving blood in the operating room because of its distance from the blood bank.

Methods: The task force implemented (1) an electronic positive patient identification (ePPID) system, (2) a standardized computer provider order entry (CPOE) for ordering blood for surgical patients, and (3) an electronic remote blood issuing (ERBI) system using refrigerators located within the operating suite.

Results: Following ePPID implementation, transfusion documentation compliance rates improved from 71% to 98% and detected 2 patient safety issues. Implementation of CPOE with a maximum surgical blood order schedule and ERBI led to a substantial decline in blood product dispensed from coolers and reduced returns of unused red blood cells (from 30% to 15%) and plasma units (from 45% to 30%) to the blood bank over 2 years.

Discussion: Electronic PPID, CPOE, and ERBI improved patient safety, workflow, and efficiency during blood transfusions.

Introduction: The Clinical Laboratory Improvement Amendments require nonconforming safety event identification, targeted intervention, and evaluation of interventional effectiveness. Without a standardized reporting structure, risk and safety teams will experience ongoing challenges with situational awareness and mitigation strategies in the workplace.

Methods: A 15-minute risk and safety huddle was initiated. The cadence was set to daily for the first iteration of huddle integration. A subsequent cadence was set to twice weekly, with a Microsoft Teams channel for streamlined communication across all laboratory settings.

Results: Huddling resulted in an averaged time savings of 14 days (approximately 2 weeks), measured from event to safety report. An observed reduction of 17.6% in employee-reported occupational safety events was noted between quarters 1 and 2 of 2023 and between quarters 1 and 2 of 2024, with a reduction in overall event spending ($458.50 [19.2%]) noted in 4 of the 5 measured safety event categories. An annual reduction in spending ($9568.09 [49.8%]) across all 5 measured safety event categories was noted in the 2022 (preinterventional) and 2023 (postinterventional) time frame.

Discussion: Laboratories should consider the establishment of a dedicated safety committee and cadenced huddles because such tools are effective for improving safety and communicating occupational hazards.