Gamma heavy chain disease in a patient with rheumatoid arthritis – a laboratory evaluation

Introduction: Heavy chain diseases (HCD) are neoplastic proliferations of B cells which secrete truncated immunoglobulin heavy chains without associated light chains. Being rare and probably underdiagnosed diseases the aim of this report is to show an additional case of gamma heavy chain disease in a 48 year old female patient with rheumatoid arthritis focusing on the laboratory presentation. Materials and methods: Laboratory work-up included agarose gel electrophoresis (AGE), capillary zone electrophoresis (CZE), immunofixation and nephelometrically determined immunoglobulin and immunoglobulin subclasses of the patient’s serum. Urine samples were also subjected to immunofixation and to a SDS-PAGE with consecutive immunoblot. Results: Nephelometrically measured elevated IgG concentrations were noted in combination with a decreased gamma globulin region and an increased beta globulin region on AGE. A definite monoclonal spike was not identified on AGE but at least suspected on CZE; finally serum and urine immunofixation demonstrated a monoclonal gamma heavy chain devoid of any corresponding light chains confirming the diagnosis of HCD. Analysis of the gamma heavy chain (HC) with means of SDS-PAGE revealed proteins of 40 kD and 80 kD most likely presenting a truncated HC in its monomeric and dimeric form and possibly leading to the failure of IgG-subclass typing with the applied IgG subclass antisera. Conclusion: This case report illustrates a new case of gamma HCD demonstrating variable laboratory manifestations and therefore the need for heightened awareness concerning this disease when confronted with abnormal and discrepant protein profiles in routinely applied laboratory tests

Alzheimer's Disease Plasma Biomarkers Distinguish Clinical Diagnostic Groups in Memory Clinic Patients

INTRODUCTION: Several recent research studies show high performance of blood biomarkers to identify Alzheimer's disease also in the pre-dementia mild cognitive impairment (MCI) stage, but data from the routine clinical care memory clinic setting are needed. METHODS: We examined plasma samples of 144 memory clinic patients, including dementia of Alzheimer type (DAT, n = 54), MCI (n = 57), and subjective cognitive decline (SCD, n = 33), who either presented as self-referrals or were referred by general practitioners or neurologists or psychiatrists. The plasma biomarkers, amyloid-beta42 (Aß42), amyloid-beta40 (Aß40), phospho-Tau181 (pTau181), total-tau (tTau), and neurofilament light (NFL), as well as different ratios, were measured using the ultrasensitive single molecule array (Simoa) immunoassay technology. Statistical analysis including Kruskal-Wallis test, linear regression, and receiver operating characteristics analyses was performed. RESULTS: Of the single markers, we observed statistically significant group effects of pTau181 (H(2) = 34.43, p < 0.001) and NFL (H(2) = 27.66, p < 0.001). All individual group comparisons of pTau181 were significant, while the contrast of SCD versus MCI for NFL was not significant. In addition, the ratios of Aß42/Aß40 (H(2) = 7.50, p = 0.02) and pTau181/Aß42 (H(2) = 25.26, p < 0.001) showed significant group effects with significant difference between all groups for pTau181/Aß42 and an SCD versus MCI difference for Aß42/Aß40. PTau181 showed the highest area under the curve of 0.85 for the discrimination of SCD and DAT with a sensitivity of 80% and a specificity of 79% at a cut-off of 12.2 pg/mL. Age influenced Aß42, Aß40, and NFL concentrations. CONCLUSION: Plasma pTau181 and NFL, as well as the ratios Aß42/Aß40 and pTau181/Aß42, are biomarkers, which can differentiate diagnostic groups in a memory clinic setting outside of research studies

Point-of-care testing (POCT) and IT security concepts

Point-of-care testing (POCT) has been an essential service in hospitals for many years with a main focus on reliability, classical laboratory quality criteria and easy handling. Hospital information technology (IT) security regulations, however, have not yet been adapted to the specificities of POCT. Following the POCT Symposium in Munich, the 1st Round Table POCT-IT-Security Meeting held in October 2019 in Cologne addressed these issues and managed to establish first consensus results in the essential fields of user, data and update management, as well as network connections and user-friendliness. First practical steps include optimizing the user management by connection to a directory service and definition of access control (including emergency authorization). Patient data economy on analyzers in combination with data and data transmission encryption as well as technically secure communication protocols are relevant steps in the fields of data management and network connections. An update management needs to be contractually defined for remote services and generally includes testing in a protocol-based scenario. Providing an organizational structure for POCT-IT security is a necessary prerequisite, as are continuous training and awareness for this topic with a strong focus on usability

Venous blood gas analysis in patients with COVID-19 symptoms in the early assessment of virus positivity

Objectives: Coronavirus disease 2019 (COVID-19) is currently a worldwide major health threat. Recognizing hypoxia in patients early on can have a considerable effect on therapy success and survival rate. Methods: We collected data using a standard blood gas analyzer from 50 patients and analyzed measurements of partial pressure of carbon dioxide-pCO(2), partial pressure of oxygen-pO(2) and oxygen saturation-sO(2), bicarbonate concentrations-HCO3- as well as ionized calcium concentrations. We further examined PCR test results for SARS-CoV-2 of the patients and analyzed differences between patients tested positive and those tested negative for the virus. Results: Venous pCO(2) was significantly higher whereas pO(2) and sO(2) were significantly lower in patients who tested positive for SARS-CoV-2. The pH, and ionized calcium concentrations of patients tested positive for the virus were significantly lower than in those tested negative. Conclusions: Symptomatic SARS-CoV-2-positive patients upon admission to the emergency room exhibit lower venous blood levels of oxygen, pH, and calcium and higher levels of carbon dioxide compared to symptomatic SARS-CoV2-negative patients. This blood gas analysis constellation could help in identifying SARS-CoV-2-positive patients more rapidly and identifying early signs of hypoxia

Anti-glycolipid antibodies in patients with neuropathy: A diagnostic assessment

Anti-glycolipid antibodies are associated with immune-mediated neuropathies and screening is often performed as part of the diagnostic assessment for patients presenting with peripheral neuropathy. We report our experience in testing for immunoglobulin (Ig) G and IgM anti-glycolipid (GM1, GM2, GM3, GM4, GD1a, GD1b, GD2, GD3, GT1a, GT1b, GQ1b, sulfatides) antibodies in 290 consecutive patients presenting with neuropathy. Anti-glycolipid antibodies were detected significantly more often (43%) in patients who were diagnosed with definite immune-mediated neuropathy than in patients without a final diagnosis of immune-mediated neuropathy (control group) (23%). With positive and negative predictive values of 22% and 90%, respectively, anti-glycolipid antibodies are not a very reliable diagnostic tool in early patient contact. Certain antibodies (IgM to GM2, GT1a and IgG to GM3, GD3 and GT1b) were equally or more prevalent in the control group; clinicians should be aware of this distribution when receiving positive screening results for these antibodies. Concomitant IgG and IgM reactivities were found for GM1, GM2, GD1b and sulfatides, and were detected more frequently in patients with definite immune-mediated neuropathies. (C) 2013 Elsevier Ltd. All rights reserved

Gamma heavy chain disease in a patient with rheumatoid arthritis – a laboratory evaluation

Introduction: Heavy chain diseases (HCD) are neoplastic proliferations of B cells which secrete truncated immunoglobulin heavy chains without associated light chains. Being rare and probably underdiagnosed diseases the aim of this report is to show an additional case of gamma heavy chain disease in a 48 year old female patient with rheumatoid arthritis focusing on the laboratory presentation. Materials and methods: Laboratory work-up included agarose gel electrophoresis (AGE), capillary zone electrophoresis (CZE), immunofixation and nephelometrically determined immunoglobulin and immunoglobulin subclasses of the patient’s serum. Urine samples were also subjected to immunofixation and to a SDS-PAGE with consecutive immunoblot. Results: Nephelometrically measured elevated IgG concentrations were noted in combination with a decreased gamma globulin region and an increased beta globulin region on AGE. A definite monoclonal spike was not identified on AGE but at least suspected on CZE; finally serum and urine immunofixation demonstrated a monoclonal gamma heavy chain devoid of any corresponding light chains confirming the diagnosis of HCD. Analysis of the gamma heavy chain (HC) with means of SDS-PAGE revealed proteins of 40 kD and 80 kD most likely presenting a truncated HC in its monomeric and dimeric form and possibly leading to the failure of IgG-subclass typing with the applied IgG subclass antisera. Conclusion: This case report illustrates a new case of gamma HCD demonstrating variable laboratory manifestations and therefore the need for heightened awareness concerning this disease when confronted with abnormal and discrepant protein profiles in routinely applied laboratory tests

C-Reactive Protein and Lymphocyte-to-Monocyte Ratio Predict Recurrence in Stage III Melanoma Patients with Microscopic Sentinel Lymph Node Metastasis

Although adjuvant therapies with immune checkpoint inhibitors (ICI) and BRAF/MEK inhibitors improve recurrence-free survival (RFS) in stage III melanoma patients significantly, prognostic factors are needed to identify patients with a high risk of disease recurrence. Therefore, the aim of our study was to investigate the prognostic potential of routinely collected blood parameters for stage III melanoma patients with microscopic sentinel lymph node (SLN) metastasis. Altogether, we retrospectively analyzed 138 stage III melanoma patients who were diagnosed with microscopic SLN metastasis at the skin cancer center of the University Hospital Cologne between 2011 and 2020 and who did not receive prior adjuvant therapy with ICI or BRAF/MEK-inhibitors. Univariate and multivariate Cox regression analyses, Kaplan&ndash;Meier survival analyses and receiver operating characteristic (ROC) curves were performed to assess the impact of preoperatively collected blood parameters and blood ratios on recurrence-free survival (RFS; primary endpoint) and overall survival (OS). A high neutrophil-to-lymphocyte ratio (NLR), low lymphocyte-to-monocyte ratio (LMR) and high C-reactive protein (CRP) value were significantly associated with shorter RFS in multivariate analysis. For LMR (cut-off 3.5) and for CRP (cut-off 3.0) this effect remained after dichotomization. CRP showed a stronger association with RFS than NLR or LMR, with the highest association being detected for the combination of low LMR and high CRP. Additionally, derived NLR &ge; 2.0 was significantly associated with shorter OS in multivariate analysis. In summary, our data suggest that CRP in combination with LMR should be considered as a marker for melanoma recurrence in stage III melanoma patients with microscopic SLN metastasis