Combined Subcutaneous Fat Aspirate and Skin Tru-Cut Biopsy for Amyloid Screening in Patients with Suspected Systemic Amyloidosis.

Screening for systemic amyloidosis is typically carried out with abdominal fat aspirates with varying reported sensitivities. Fat aspirates are preferred for use in primary screening instead of organ biopsies as they are less invasive and thereby minimize the potential risk of complications. At Odense Amyloidosis Center, we performed a prospective study on whether the combined use of fat aspirate and tru-cut skin biopsy could increase the diagnostic sensitivity. Both fat aspirates and skin biopsies were screened with Congo Red staining, and positive biopsies were subsequently subtyped using immunoelectron microscopy and mass spectrometry. Seventy-six patients were included. In total, 24 patients had systemic amyloidosis (11 AL, 12 wtATTR, 1 AA), and 6 patients had localized amyloidosis. Combined fat aspirate and skin biopsy were Congo Red-positive in 15 patients (overall sensitivity (OS) 62.5%). Fat aspirates were positive in 14 patients (OS 58.3%), and the skin biopsy was positive in 5 patients (OS 20.8%). In only one patient did the skin biopsy add extra diagnostic information. The sensitivity differed between AL and ATTR amyloidosis-81.8% and 41.7%, respectively. Using skin biopsy as the only screening method is not recommended.

Classification of Amyloidosis by Model-Assisted Mass Spectrometry-Based Proteomics.

Amyloidosis is a rare disease caused by the misfolding and extracellular aggregation of proteins as insoluble fibrillary deposits localized either in specific organs or systemically throughout the body. The organ targeted and the disease progression and outcome is highly dependent on the specific fibril-forming protein, and its accurate identification is essential to the choice of treatment. Mass spectrometry-based proteomics has become the method of choice for the identification of the amyloidogenic protein. Regrettably, this identification relies on manual and subjective interpretation of mass spectrometry data by an expert, which is undesirable and may bias diagnosis. To circumvent this, we developed a statistical model-assisted method for the unbiased identification of amyloid-containing biopsies and amyloidosis subtyping. Based on data from mass spectrometric analysis of amyloid-containing biopsies and corresponding controls. A Boruta method applied on a random forest classifier was applied to proteomics data obtained from the mass spectrometric analysis of 75 laser dissected Congo Red positive amyloid-containing biopsies and 78 Congo Red negative biopsies to identify novel "amyloid signature" proteins that included clusterin, fibulin-1, vitronectin complement component C9 and also three collagen proteins, as well as the well-known amyloid signature proteins apolipoprotein E, apolipoprotein A4, and serum amyloid P. A SVM learning algorithm were trained on the mass spectrometry data from the analysis of the 75 amyloid-containing biopsies and 78 amyloid-negative control biopsies. The trained algorithm performed superior in the discrimination of amyloid-containing biopsies from controls, with an accuracy of 1.0 when applied to a blinded mass spectrometry validation data set of 103 prospectively collected amyloid-containing biopsies. Moreover, our method successfully classified amyloidosis patients according to the subtype in 102 out of 103 blinded cases. Collectively, our model-assisted approach identified novel amyloid-associated proteins and demonstrated the use of mass spectrometry-based data in clinical diagnostics of disease by the unbiased and reliable model-assisted classification of amyloid deposits and of the specific amyloid subtype.

Myc protein overexpression is a feature of progression and adverse prognosis in multiple myeloma.

OBJECTIVE: Prognostic and predictive markers in multiple myeloma are continuously explored because of the heterogeneity of the tumor biology. Myc protein is the final product from activating MYC oncogene, but the prognostic impact in multiple myeloma is not well described. METHODS: In a population-based cohort of 194 untreated, newly diagnosed patients with multiple myeloma, we assessed myc protein expression using CD138/myc immunohistochemical double stain and collected clinicopathological data. RESULTS: Cases with myc protein expression ≥40% (mycHIGH ) had a median overall survival of 11 months compared to 48 months in cases of myc protein expression <40% (mycLOW ) (P < 0.01). MycHIGH was significantly correlated to R-ISS, high proliferation index, high percentage of plasma cell in bone marrow, plasmablastic morphology, high calcium level, and abnormal karyotype. In multivariate survival analyses, mycHIGH was independently associated with inferior overall survival with a hazard ratio of 2.5. CONCLUSION: Our results indicate myc protein overexpression to be associated with advanced multiple myeloma and poor prognosis.

Proteasome inhibitors and IMiDs can overcome some high-risk cytogenetics in multiple myeloma but not gain 1q21.

Chromosomal aberrations have significant prognostic importance in multiple myeloma (MM). However, proteasome inhibitors (PI) and IMiDs may partly overcome the poor prognostic impact of some of them. In this study, we investigated a population-based consecutive cohort newly diagnosed patients with MM admitted during a defined time period to hospitals in Denmark, Norway, and Sweden. The impact of treatment modality on the prognostic importance of specific chromosomal aberration was investigated, with special reference to gain 1q21. The median follow-up of patients still alive at analysis was 40 months for the high-dose (HDT)-treated ones and 29 months for the whole population. Three hundred forty-seven patients with a known 1q21 status were included in this study. The 347 patients were divided into three groups, that is, 119 patients with the 1q21 gain, 105 patients with other aberrations (OA), that is, del(13q), del(17p), t(4,14), and/or (14;16), and 123 patients with no aberrations (NA). The groups were compared in terms of overall survival (OS), time to progression (TTP), and response. The 3-yr OS for patients with gain 1q21 was 60% compared to patients with OA 74% and NO 82% (gain 1q21 vs. NO P < 0.001; gain 1q21 vs. OA P = 0.095). If treated with PI or IMiDs, the 3-yr OS was 58% for patients with gain 1q21 compared to patients with OA 78% and NO 78%, respectively (P = 0.041, P = 0.140). In HDT patients, the 3-yr OS was 69% for patients with gain 1q21 compared to patients with OA 84% and NO 88%, respectively (P < 0.008, P = 0.600). Thus, neither HDT nor using PI or IMiDs could overcome the poor prognostic impact of gain 1q21, while these drugs and HDT seemed to improve OS in patients with OA, approaching the survival in NO. Further, gain 1q21 appears to be one of the most important poor prognostic chromosomal aberrations in multiple myeloma with current treatments. Trials using new drugs or allogeneic transplantation are warranted.

Clinicopathological features of plasmablastic multiple myeloma: a population-based cohort.

Multiple myeloma (MM) is a common malignant hematological disease displaying considerable heterogeneity. Historical data indicate a prognostic significance of plasmablastic morphology, proliferation, and adverse cytogenetics, but there is little knowledge on the degree of interdependency of these parameters. The aim of this study was to study the degree of overlap between these variables. In a consecutive population-based cohort of 194 untreated MM patients, morphology, and proliferation index, using immunohistochemical double staining for Ki-67 and CD138, was analyzed. In addition, cytogenetic changes were studied by karyotyping and fluorescence in situ hybridization (FISH). Plasmablastic morphology correlated with unfavorable clinical features, high proliferation index, high percentage of plasma cell infiltration in the bone marrow, abnormal karyotype, and del(13q) detected by karyotyping, which indicates that plasmablastic morphology reflects advanced and highly proliferative disease. However, plasmablastic morphology did not correlate with established adverse prognostic cytogenetics identified by FISH, for example, t(4;14), t(14;16) and del(17p).