A Targeted Mass Spectrometry Strategy for Developing Proteomic Biomarkers: A Case Study of Epithelial Ovarian Cancer.

Protein biomarkers for epithelial ovarian cancer are critical for the early detection of the cancer to improve patient prognosis and for the clinical management of the disease to monitor treatment response and to detect recurrences. Unfortunately, the discovery of protein biomarkers is hampered by the limited availability of reliable and sensitive assays needed for the reproducible quantification of proteins in complex biological matrices such as blood plasma. In recent years, targeted mass spectrometry, exemplified by selected reaction monitoring (SRM) has emerged as a method, capable of overcoming this limitation. Here, we present a comprehensive SRM-based strategy for developing plasma-based protein biomarkers for epithelial ovarian cancer and illustrate how the SRM platform, when combined with rigorous experimental design and statistical analysis, can result in detection of predictive analytes.Our biomarker development strategy first involved a discovery-driven proteomic effort to derive potential N-glycoprotein biomarker candidates for plasma-based detection of human ovarian cancer from a genetically engineered mouse model of endometrioid ovarian cancer, which accurately recapitulates the human disease. Next, 65 candidate markers selected from proteins of different abundance in the discovery dataset were reproducibly quantified with SRM assays across a large cohort of over 200 plasma samples from ovarian cancer patients and healthy controls. Finally, these measurements were used to derive a 5-protein signature for distinguishing individuals with epithelial ovarian cancer from healthy controls. The sensitivity of the candidate biomarker signature in combination with CA125 ELISA-based measurements currently used in clinic, exceeded that of CA125 ELISA-based measurements alone. The SRM-based strategy in this study is broadly applicable. It can be used in any study that requires accurate and reproducible quantification of selected proteins in a high-throughput and multiplexed fashion.

Gamma-heavy chain disease.

BACKGROUND: Gamma-heavy chain disease is a rare disease, described so far in approximately 150 cases. The aim of this work was laboratory dia-gnostics of immunoglobulin heavy chain disease. MATERIALS AND METHODS: A 60-year-old patient was referred to the University Hospital in Ostrava for suspected marginal zone lymphoma from gastric bio-psy. Staging examinations including bone marrow trepanobio-psy and PET/CT were added; special examinations required serum protein electrophoresis, immunofixation electrophoresis, determination of polyclonal immunoglobulins, free light chains, and immunoglobulin heavy/light chain pairs. Isoelectric focusing in agarose gel followed by affinity immunoblotting and SDS electrophoresis was added due to unclear findings. RESULTS: 0.1 % of plasma cells were found in the bone marrow, of which 87 % were clonal (pathological) plasma cells, followed by the cyt cytotype LAMBDA + CD38 + CD138 + CD45 + CD19 + CD56- CD27 + CD81- CD117-. Monoclonal heavy chains were found in the patients serum. No monoclonal immunoglobulin heavy or light chains were detected in urine. The PET/CT examination showed generalized lymphadenopathy, splenomegaly and inhomogeneous accumulation of fluorodeoxyglucose in axillary and appendicular skeleton, but without the presence of typical osteolytic lesions. CONCLUSION: Monoclonal heavy chains of immunoglobulins are a rare disease. In contrast to the detection of a complete paraprotein molecule, additional methods must be used to confirm them. The finding of monoclonal heavy chain gamma in the serum of the study patient is related to the presence of marginal zone lymphoma, which was proven from a gastric bio-psy. The study was supported by the project of MH CZ - DRO - FNOs /2017 (Biobank in Teaching Hospital Ostrava) The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.

Molecular defect in a gamma-2 heavy chain.

The first gamma-2 (gamma2) heavy chain disease protein Gif has pyrroli-dinecarboxylic acid as its amino terminal residue, much of the Fd variable region, and an internal deletion of the heavy chain of about 100 residues corresponding to most of the Fd constant region. Normal sequence resumes with a glutamic acid residue at position 216 in the hinge region. This is the third gamma heavy chain disease protein where normal sequence resumes at the same position after the deletion.

Cutis laxa for diagnosis of γ1-heavy-chain deposition disease: Report of four cases.

Heavy-chain deposition disease (HCDD) is characterized by tissue deposits of a truncated monoclonal immunoglobulin heavy-chain (HC) on basement membranes. Diagnosis is usually made on kidney biopsy, showing nodular glomerulosclerosis with HC deposits which can be missed, resulting in delay in diagnosis. We report four γ1-HCDD patients presenting with cutis laxa, hypocomplementemia and hypoalbuminemia. In two patients, unsuspected HCDD was revealed by cutis laxa and diagnosis was made on skin biopsy. In all patients, serum albumin and complement represented surrogate markers for disease monitoring. In γ-HCDD, extrarenal manifestations such as cutis laxa may precede renal injury and are precious tools for an early diagnosis, which is crucial to avoid progression of irreversible renal and elastic tissue damage.

Biosynthetic and structural studies of a heavy chain disease protein.

A new heavy chain disease protein ((gamma)HCD-JM) has been characterized by antigenic and structural criteria. The protein belongs to the IgG3-subclass and is closely related to Fc-fragment of G3-immunoglobulins. The predominant N-terminal amino acid of this protein is glutamic acid in the uncyclized form, and that of another (gamma)HCD is glycine. Studies of the N-terminal peptides indicate that the N-terminal portion of the (gamma)3-heavy polypeptide chain is absent from the (gamma)HCD-JM. These findings rule out a process of normal heavy chain initiation and a large deletion of the Fd region as being responsible for these two heavy chain disease proteins. The (gamma)HCD-JM is a secretory product of cells from bone marrow as shown by studies of in vitro incorporation of amino acids-(14)C. Bone marrow and lymph node have a population of lymphoplasmacytic cells which by immunofluorescence contain (gamma)-heavy chain antigens in the absence of light chain antigens.

Gamma heavy chain "disease": heterogeneity of the clinicopathologic features. Report of 16 cases and review of the literature.

This review underscores the diversity of the clinical manifestations and hematopathological features of gamma heavy chain disease based on the detailed report of 16 patients evaluated in our chemical department, the analysis of 12 cases diagnosed in our laboratory, and the study of 81 cases previously reported. This condition is defined by the presence in the serum of immunoglobulin molecules composed of deleted gamma heavy chains devoid of light chains. The production by the monoclonal B cells of these peculiar proteins appears to result from multiple defects (deletions, insertions, and mutations) in both heavy and light chain genes leading to abnormal mRNA splicing. Gamma heavy chain disease is currently underdiagnosed. The diagnosis established by immunoelectrophoresis using specific antisera combined, in some instances, with the immunoselection procedure, can easily be missed on serum electrophoretic patterns: a narrow abnormal band suggestive of a monoclonal component was found in only 10 of our 28 cases. The amount of heavy chain disease protein in urine ranges from trace to 20 g/day and is usually moderate. Gamma heavy chain disease most often presents as a lymphoproliferative disorder featured by lymphadenopathies, splenomegaly, and constitutional symptoms. Extra-hematopoietic tumor localizations, such as cutaneous or subcutaneous involvement or thyroid tumor, may occur. Autoimmune disorders, notably rheumatoid arthritis and autoimmune hemolytic anemia or thrombocytopenic purpura, are frequent (26% of cases). There is no specific histological pattern. The most frequent is a pleomorphic malignant lymphoplasmacytic proliferation mainly seen in bone marrow and lymph nodes. Some cases present with a predominantly plasmacytic proliferation or chronic lymphocytic leukemia. Other patients are affected with non-Hodgkin lymphoma of various morphologic types. Immunocytologic studies showed that a gamma heavy chain disease protein may occur in the context of a double monoclonal lymphoproliferative process or in various B or T cell malignancies that are not directly involved in the production of the abnormal immunoglobulin. In some patients, the histologic appearance of the enlarged lymphoid organs showed only a moderate lymphoplasmacytic infiltration of uncertain malignancy. More important, some patients showed no evidence of an underlying lymphoproliferative disorder after several years of follow-up. The clinical course of gamma heavy chain disease varies from an asymptomatic state to a rapidly progressive malignancy. The choice of therapy should entirely rely on the underlying clinicopathologic features, without taking into account the presence of the abnormal protein.(ABSTRACT TRUNCATED AT 400 WORDS)

Detection of CD55- and/or CD59-deficient red cell populations in patients with plasma cell dyscrasias.

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal disorder characterized by a decrease or absence of glycosylphosphatidylinositol (GPI)-anchored molecules such as CD55 and CD59 from the surface of affected cells, resulting in intravascular hemolysis, cytopenia, and venous thrombosis. A PNH-like phenotype has been detected in various hematological disorders, mainly in aplastic anemia and myelodysplastic syndromes, but also in lymphoproliferative syndromes (LPSs). To the best of our knowledge, CD55- or CD59-deficient red cells have not been detected in plasma cell dyscrasias (PCDs). The aim of this study was the detection of CD55- and/or CD59-deficient red cell populations in patients with PCD. Seventy-seven patients were evaluated; 62 with multiple myeloma (MM), 7 with Waldenstrom macroglobulinemia (WM), 6 with monoclonal gammopathy of undetermined significance (MGUS), and 2 with heavy chain disease (HCD). The sephacryl gel microtyping system was applied; Ham and sucrose lysis tests were also performed on all samples with CD55- or CD59-negative populations. Red cells deficient in both molecules were detected in 10 (12.9%) of 77 patients with PCD: 2 (28.6%) of 7 with WM, 1 (16.6%) of 6 with MGUS, 6 (9.6%) of 62 with MM, and 1 of 2 patients with HCD. Isolated CD55 deficiency was found in 28.5% of all PCD patients, whereas isolated CD59 deficiency was not observed in any patients. These findings illustrate the existence of the PNH phenotype in the red cells of patients with PCD; further investigation is needed into the mechanisms and significance of this phenotype.

Gamma heavy chain disease screening showing a discrepancy between electrophoretic and nephelometric determinations of serum gamma globulin concentration.

A 75-year-old woman with rheumatoid arthritis showed a discrepancy between the reduced level of serum gamma globulin on cellulose acetate electrophoresis and the normal level of serum IgG determined by laser nephelometry. Although no M-peak was detectable on cellulose acetate electrophoresis, immunoelectrophoresis of the patient's serum revealed a monoclonal protein reacting with anti-IgG antiserum but not with anti-kappa or anti-lambda light chain antiserum. Western blotting of the patient's serum showed abnormal low-molecular-weight gamma chains. Thus, the patient was diagnosed with gamma heavy chain disease. A comparison of gamma globulin levels determined by different methods may be useful when screening for this disease.

Five unusual serum protein presentations found by capillary electrophoresis in the clinical laboratory.

Capillary electrophoresis (CE) has been used in our teaching hospital clinical laboratory to assay approximately 13 000 specimens for serum protein electrophoresis (SPE) in 4 1/2 years. During that period we have found several unusual samples, five of which are discussed here. These samples are from separate patients with IgD myeloma, IgG heavy chain disease, a triple IgG(Kappa) monoclonal band, a rapidly changing abnormal/monoclonal band and a mixed type-11 cryoglobulinaemia. Albumin has been used to calibrate the 50-microm fused silica capillary, the quantity of the monoclonal bands being calculated by the software of either the Applied Biosystems 270A-HT or BioFocus instrument. We have found CE for the initial SPE to be a robust, labour-saving, cost effective technique, which is able to determine less than 1 g/l of monoclonal protein. However, because of the expense and time required for immunosubtraction, we prefer isoelectric focusing (IEF) for typing of paraproteins. The only samples which need care in handling are serum containing large amounts of cryoglobulin protein.

Electrophoretic characterization of a gamma-1-heavy chain disease.

This report describes a new case of gamma-1-heavy chain disease found in a woman with malignant lymphoproliferative disease. The patient's serum and urine containing gamma-1-heavy chains were analyzed using different electrophoretic approaches, especially two-dimensional electrophoresis and immunoblotting analysis. In a serum sample, five sets of gamma-1-heavy chain spots differing in molecular weight with acidic pI values and one set of more basic gamma-1-heavy chain spots were found. The major group of spots exhibited molecular weight in the range from 29 to 39 kDa. Examination of urine sample proved the presence of the more basic set of gamma-1-heavy chain spots and two acidic groups, including 29 to 39 kDa set.

Acute phase reactant proteins in differential diagnosis of monoclonal gammopathy.

The serum levels of five individual serum proteins, i.e. ceruloplasmin, alpha 1-antitrypsin, orosomucoid, haptoglobin and transferrin, were studied in 55 multiple myeloma (MM) patients, in 34 essential monoclonal gammopathy (EMG) patients, in 14 EMG patients excluded for active inflammatory process and in 14 healthy control subjects. Transferrin--negative acute phase reactant (APR)--was significantly decreased and the remaining proteins under study--positive APR--slightly increased in the EMG group compared with healthy controls. Transferrin and ceruloplasmin levels were significantly different when the MM was compared to the EMG group so that these parameters might be useful in differential diagnosis between both groups. In the MM clinical stage III, the differences are even more significant. In the IgG3 MM the APR levels seem to be more significantly changed than in the IgG1 and IgG2 MM. In EMG patients with active inflammatory process who were excluded ceruloplasmin, alpha 1-antitrypsin, orosomucoid and haptoglobin were significantly increased when compared with the EMG group.

[Alpha heavy chain disease. Molecular analysis of a new case]. / Maladie des chaînes lourdes alpha. Analyse moléculaire d'un nouveau cas.

The NH2-terminal structure of serum abnormal protein, as well as the sequence of the corresponding mRNA, were determined in a new case of alpha heavy chain disease. The patient presented with typical clinical features of the disease. Intestinal and mesenteric lymphoplasmic infiltration was monoclonal as assessed by the study of the configuration of heavy and light chain genes. The serum abnormal alpha chains included two molecular species: one starting at the beginning of the hinge region and the other being two amino acids shorter, missing the two first amino acids of the hinge region. The sequence of the mRNA displayed a leader exon, a 93 bp sequence of unknown origin and the second and third constant exons of human alpha 1 chain. These data are discussed in the light of previously reported molecular studies in heavy chain diseases.

Gamma heavy-chain disease: defining the spectrum of associated lymphoproliferative disorders through analysis of 13 cases.

Gamma heavy-chain disease (gHCD) is defined as a lymphoplasmacytic neoplasm that produces an abnormally truncated immunoglobulin gamma heavy-chain protein that lacks associated light chains. There is scant information in the literature regarding the morphologic findings in this rare disorder, but cases have often been reported to resemble lymphoplasmacytic lymphoma (LPL). To clarify the spectrum of lymphoproliferative disorders that may be associated with gHCD, this study reports the clinical, morphologic, and phenotypic findings in 13 cases of gHCD involving lymph nodes (n=7), spleen (n=2), bone marrow (n=8), or other extranodal tissue biopsies (n=3). Clinically, patients showed a female predominance (85%) with frequent occurrence of autoimmune disease (69%). Histologically, 8 cases (61%) contained a morphologically similar neoplasm of small lymphocytes, plasmacytoid lymphocytes, and plasma cells that was difficult to classify with certainty, whereas the remaining 5 cases (39%) showed the typical features of one of several other well-defined entities in the 2008 WHO classification. This report demonstrates that gHCD is associated with a variety of underlying lymphoproliferative disorders but most often shows features that overlap with cases previously reported as "vaguely nodular, polymorphous" LPL. These findings also provide practical guidance for the routine evaluation of small B-cell neoplasms with plasmacytic differentiation that could represent a heavy-chain disease and give suggestions for an improved approach to the WHO classification of gHCD.