Advances in laboratory medicine最新文献

Objectives: To describe a variant hemoglobin that interferes with HbA_1c analysis by cation exchange HPLC.

Case presentation: A 78 years-old Spanish male patient visited the Internal Medicine Clinic for a routine check-up, with HbA_1c included to screen for diabetes. He had suffered hypertension and dyslipidemia, and the patient had no previous symptoms suggestive of diabetes such as hyperglycemia, weight loss, polydipsia, polyuria or tiredness. Diabetes screening by HbA_1c measurement was assessed using cation exchange HPLC and an immunoassay point-of-care analyzer. Routine hemoglobinopathy screening was performed including CBC, HbF and HbA₂ measurement by cation exchange HPLC and capillary electrophoresis (CE). Further variant characterization was undertaken by DNA sequencing. Discordant HbA_1c results were obtained for our subject, with elevated HbA_1c of 52 mmol/mol measured by cation exchange HPLC and a normal level of 34 mmol/mol by immunoassay. Abnormal HbA_1c peak shape prompted hemoglobinopathy screening to investigate potential variant interference. A globin gene analysis was performed, and the results showed a variant hemoglobin named 'Hb Petie Salpetriere'. This variant arises from a Val → Phe substitution due to a mutation of c.103G>T of the beta-globin gene [BETA34 (B16) Val>Phe; HBB:c.103G>T].

Conclusions: This is the first reported case involving the Hb Petie Salpetriere variant in a Spanish patient. The present results show that the Hb Petie Salpetriere variant can affect the results of HbA_1c analysis through ion-exchange HPLC, but not that obtained from the latex agglutination immunoassay. Only ion-exchange HPLC suggested the presence of the Hb variant in this case, suggesting that a careful review of the resulting chromatogram might reveal a potential variant.

Objectives: Laboratory testing has an extensive role in the diagnosis of monoclonal gammopathies. Since the last updates of the International Myeloma Working Group (IMWG) guidelines for the diagnosis of monoclonal gammopathies, debate has arisen as to whether urine analysis remains relevant for the diagnosis of these entities.

Methods: We carried out a retrospective study with data from 132 patients with a newly diagnosed serum M-protein. Patients were divided into two groups depending on the presence of M-protein in urine and different variables were recorded and statistically compared between groups.

Results: The aim of the study was to find a serum M-protein cut-off value under which urine analysis could be avoided in the first laboratory diagnosis. The results show that when the concentration of serum M-protein is ≤3.5 g/L and eGFR is >30 mL/min/1.73 m² (sensitivity (S): 100 %, specificity (Sp): 49 %, negative-predictive value (NPV): 100 %) the probability of finding M-protein in urine is negligible. Patients with alpha heavy chain have a higher probability of having M-protein in urine. Thus, when the heavy chain of the M-protein is gamma or mu, serum cut-off value can be raised up to ≤4.9 g/L (S: 97 %, Sp: 52 %, NPV: 98 %).

Conclusions: Settling these two cut-off values when a new M-protein is discovered could avoid a significant number of urine analyses, optimizing laboratory and healthcare resources.

Objectives: BCR-ABL kinase domain mutations are an important cause of resistance to tyrosine kinase inhibitors (TKIs) in chronic myeloid leukaemia (CML) of which T315I is the most treatment-resilient. This study aimed to observe the frequency of T315I and its impact on disease prognosis in terms of progression and survival.

Methods: Patients with a response which categorized them into warning zone/or who failed to respond to their TKI treatment completely as per the European LeukemiaNet (ELN) were labeled as non-responders. They were assessed for T315I mutation using amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) and validated via sequencing. Patients were then longitudinally followed for 96 months for the prognostic impact of the mutation.

Results: Of the 102 non-responders, T315I mutation was detected in 21.6 % of patients with a female preponderance. Almost 59 % of mutation-harbouring patients were labelled as low Sokal risk at baseline. The disease progression into the blastic phase was reported in 58.8 % of mutation-harbouring patients. Overall survival (study period: 96 months) was 81.8 % in patients harbouring T315I mutation. Patients in the blastic phase had significant odds of harbouring T315I mutation.

Conclusions: Sub-optimal response or failure to TKI treatment indicates the development of resistance due to the presence of T315I mutation or other mutation(s). Early identification will help redirect the patient's treatment.

Objectives: Semen analysis investigates different parameters of human semen with a high relevance in fertility workup, confirmation of sterility by post vasectomy, in pathologies follow-up such as varicocele and in all cases where sperm preservation is required. Manually seminal fluid examination is characterized by poor reproducibility. Aim of this study was to evaluate the performance of an automatic device in semen analysis by comparing its results with those obtained with the manual microscopy.

Materials: Fifty samples (age 18-59 years) were analyzed simultaneously by the manual and automated method. Manual analysis was performed by at least two experienced operators. Concentration and motility were determined by means of standard manual analysis and by the automated LensHooke™ analyzer following the last WHO guidelines.

Results: We compared the concentration (million/mL) of spermatozoa obtained from manual and instrumental count and different classifications obtained: normal, oligospermic, cryptospermic and azoospermic samples. The Wilcoxon test does not show a statistically significant difference. The Bland-Altman plot showed a slightly higher value for the manual count. Second, we compared the morphology and the samples classification in morphological normal and abnormal. Third, spermatozoa motility obtained from the manual and instrumental count was compared with a different classification in normal total motility and asthenozoospermia. Statistical tests showed respectively for morphology and motility a moderate and a very good agreement.

Conclusions: Our study demonstrates that the LensHooke™ shows an acceptable agreement with the manual microscopic seminal fluid evaluation. The use of this simple device could help to standardize reports in non specialistic laboratories.

Introduction: Retrograde ejaculation (RE) consists of the reflux backwards, towards the bladder, of the ejaculate, during the emission phase of ejaculation, causing a total or partial absence of sperm emission, with the consequent diversion of semen into the bladder during the emission phase of ejaculation. Evaluating the ejaculate may not be sufficient for identifying RE in some patients. Hence, the management of infertility may involve the use of invasive methods such as epididymal fluid retrieval or testicular biopsy.

Content: This paper defines RE and methods for its diagnosis. A description is also provided of the techniques used for the detection of sperm in post-ejaculatory urine (PEU), the preparation and retrieval of sperm from urine and their subsequent use in assisted reproductive techniques.

Summary: The diagnosis of RE is based on the detection of spermatozoa in PEU in patients with aspermia or oligozoospermia and low or normal seminal volume. Although the presence of sperm in PEU could be sufficient for a diagnosis of RE, there is a lack of consensus regarding the diagnostic criteria for PEU, and the literature available is very limited. A correct diagnosis of RE allows the use of PEU for recovering sperm and its subsequent use in assisted human reproduction techniques, thus avoiding invasive techniques.

Outlook: A significant number of patients with RE may remain undiagnosed. Therefore, it is essential to conduct an RE study in patients with suspicion, through the analysis of PEU, and to properly interpret the results for accurate diagnosis.

Objectives: Unexplained B12 hypervitaminosis (HB12) in asymptomatic patients leads to a cascade of medical consultations and diagnostic tests aimed at determining its etiology. The objective of this study was to assess the efficacy of the laboratory getting involved in the detection and elimination of immune complexes with vitamin B12 in clinical practice and its economic impact.

Methods: A retrospective longitudinal study was undertaken to assess the laboratory strategy of detecting B12 macrovitamin (macro-B12) in patients with HB12 >1,000 pg/mL. The clinical characteristics of patients with HB12 referred to Internal Medicine (IM) in the pre- and post-implantation period of the new strategy were compared. Additionally, the healthcare costs of one-year follow-up were estimated.

Results: The prevalences of HB12 in the pre- and post-implantation period were 3.9 % and 3 %, respectively. Macro-B12 explained 25 % of the HB12 cases initially detected. A 41 % reduction was observed in the number of patients with HB12 after the implantation of the new strategy, thereby resulting in a cost reduction of 5,000 €.

Conclusions: The laboratory intervention for the detection of macro-B12 provides clear economic and clinical benefits in clinical practice.