Case report: Interference from isatuximab on serum protein electrophoresis prevented demonstration of complete remission in a myeloma patient

Multiple myeloma is a haematological cancer caused by malignant plasma cells in the bone marrow that can result in organ dysfunction and death. Recent novel treatments have contributed to improved survival rates, including monoclonal antibody therapies that target the CD38 protein on the surface of plasma cells. Anti-CD38 therapies are IgG kappa monoclonal antibodies that are given in doses high enough for the drug to be visible on serum protein electrophoresis as a small paraprotein. We present a case where isatuximab, the most recent anti-CD38 monoclonal antibody to be approved for treatment of myeloma, obscured the patient’s paraprotein on gel immunofixation, so that complete remission could not be demonstrated. This was resolved using the isatuximab Hydrashift assay. The interference on gel immunofixation was unexpected because isatuximab migrated in a position distinct from the patient’s paraprotein on capillary zone electrophoresis. We demonstrate the surprising finding that isatuximab migrates in a different position on gel electrophoresis compared to capillary zone electrophoresis. It is vital that laboratories are aware of the possible interference on electrophoresis from anti-CD38 monoclonal antibody therapies, and are able to recognise these drugs on protein electrophoresis. The difference in isatuximab’s electrophoretic mobility on capillary and gel protein electrophoresis makes this particularly challenging. Laboratories should have a strategy for alternative analyses in the event that the drugs interfere with assessment of the patient’s paraprotein.

Nucleic acid & protein electrophoresis v2

This protocol concludes two types of the electrophoresis used to detect target DNA or protein.

Nucleic acid & protein electrophoresis v1

This protocol concludes two types of the electrophoresis used to detect target DNA or protein.

Screening Tests for Early Diagnosis of Multiple Myeloma and Related Plasma Cell Disorders

Monoclonal gammopathy (MG) encompasses a diverse group of disorders characterized by the secretion of monoclonal immunoglobulins or their light-chain components. The incidence of multiple myeloma (MM) in South Korea is rapidly increasing, and it is important to be aware of its initial clinical presentations and the most efficient laboratory algorithms for early detection. Serum protein electrophoresis (SPE) and urine protein electrophoresis (UPE) are the primary screening tests for patients with clinically suspected MM or amyloid light-chain amyloidosis; these tests are reimbursed in South Korea. We reviewed clinical studies that applied national and international guidelines to evaluate test panels for early detection of MGs, including MM. The serum free light chain (sFLC) with SPE panel is recommended for the initial work up for diagnosis of MGs. In the case of a normal SPE, sFLC should be measured subsequently, so as not to miss the presence of M-protein. Use of this screening panel avoids medical expenses related to delayed diagnosis. Guidelines and recommendations suggest that no single method (SPE, serum immunofixation electrophoresis, sFLC, or UPE) should be used to exclude a diagnosis of MM. We believe that a screening test panel comprising SPE plus sFLC will increase the rate of early and accurate diagnosis of MM and related disorders.

Elevated serum gamma globulins in apparently healthy Nigerians living in Ogbomoso: A possible manifestation of phagocytic dysfunction

Background: Serum protein electrophoresis abnormalities, particularly elevated gamma globulins (hypergammaglobulinemia), have been reported in apparently healthy Nigerians living in Ogbomoso and elsewhere. Since the mechanisms for this phenomenon have not been fully substantiated, we hypothesized that impaired neutrophil phagocytosis could contribute to this condition. Methods: Healthy humans exhibiting hypergammaglobulinemia (HGG) were identified using serum protein electrophoresis (SPE) performed on cellulose acetate gel in barbital buffer (pH 8.6). GelQuant image analysis and quantitation software were further employed to quantify gamma globulin fraction. Neutrophils were isolated from K3EDTA anticoagulated peripheral blood using neutrophil isolation histopaque of Kayman Chemical, USA. Neutrophil phagocytic activity was analyzed using a non-subjective commercial colorimetric phagocytosis assay kit obtained from Cell-Biolab Inc, USA. Results: The purity and viability of isolated neutrophils were approximately 94 % and 92 %, respectively. Ex-vivo phagocytic activity of neutrophils isolated from apparently healthy subjects exhibiting HGG, expressed in absorbance unit (AU), was 48.1±8.6 % which was significantly lower (p<0.05); compared to the controls (98.9±14.3 %). Conclusion: Since neutrophils play crucial roles in innate immune responses, impairment of neutrophil phagocytic activity may lead to persistent antigenic stimulations of the adaptive immune system. This could in turn orchestrate γ-globulins expression leading to HGG. Statement of novelty: We demonstrated a reduced neutrophil phagocytic activity as a possible basis for hypergammaglobulinemia in healthy Nigerians, perhaps for the first time.

Prolonged Thrombin Time in Asymptomatic Patient with Hypo Dysfibrogememia Tucson

A 61 years female patient with known diagnosis of the breast cancer in remission for more than 10 years has Renaud’s disease. During her work up for lupus and lupus anticoagulant which both were negative a prolonged thrombin time was noted which was done by mistake. She has no history of bleeding or thrombosis and last recent surgery was 5 years ago for spinal stenosis and was uncomplicated. Her clinical examination is normal without evidence of any spontaneous bruises but colder hands. The thrombin time was greater than 125 seconds on two different occasions and correction of it by addition of normal plasma was down to 56 seconds and was thus incomplete. Her prothrombin time and PTT were normal and there was no evidence of FDP or D-Dimers. There was no evidence of circulating heparins. The fibrinogen level was normal. The para proteinmia was excluded by normal serum protein electrophoresis and by immunofixation . Thus it is felt that this patient has dysfibrinogenemia or hypo dysfibrinogenemia without bleeding or thrombotic complication. The literature review shows approximately 55% of dysfibrinogenemia patients do not have bleeding or thrombotic complications.