Presence of paraneoplastic antibodies in non-carcinomatous patients with neurological involvements of unknown cause

Data on the utilization of paraneoplastic syndrome autoantibody testing at an academic medical center

Paraneoplastic syndromes are rare conditions associated with characteristic autoantibodies produced by malignancy, although similar autoantibodies and clinical presentations may occur in the absence of any neoplasm. Testing for paraneoplastic syndromes often involves panels of autoantibody assays. While autoantibody testing may reveal or confirm actionable clinical diagnoses, inappropriate utilization of testing may be low yield and further lead to false positives that may confuse the clinical picture. There is thus opportunity to improve patient care by analyzing patterns of paraneoplastic autoantibody test utilization. The data in this article provides results from detailed retrospective review of patients tested by 7 autoantibody tests or test panels offered by two large reference laboratories in the United States. The data include 1,446 tests performed on 1,338 unique patients at an academic medical center. For all results, detailed chart review revealed main category of presenting symptoms, patient location at time of testing (either inpatient or outpatient), sex, age, whether cancer was present at the time of testing or later detected, and the specific results of the testing. The data are summarized by category of testing and specific autoantibodies.

Integrative metabolic profile of myelodysplastic syndrome based on UHPLC-MS

Myelodysplastic syndrome (MDS) is a neoplastic disease originating from hematopoietic stem cells. Currently, hematopoietic stem cell transplantation (HSCT) is the most effective cure, although lenalidomide, azacytidine, and decitabine have been applied to relieve symptoms of MDS. The purpose of this study was to evaluate the changes in endogenous metabolites by applying a UHPLC-MS (ultra-high-performance liquid chromatography-MS) metabolomics approach and to investigate metabolic pathways related to MDS. An untargeted metabolomics approach based on UHPLC-MS in combination with multivariate data analysis, including partial least squares discrimination analysis and orthogonal partial least squares discriminant analysis, was established to investigate potential biomarkers in the plasma of MDS patients. As a result, 29 biomarkers were identified to distinguish between MDS patients, HSCT patients, and healthy controls, which were mainly related to inflammation regulation, amino acid metabolism, fatty acid metabolism, and energy metabolism. To our knowledge, this is the first time where plasma metabolomics was combined with HSCT to study the pathogenesis and therapeutic target of MDS. The identification of biomarkers and analysis of metabolic pathways could offer the possibility of discovering new therapeutic targets for MDS in the future.

Unintended consequences of Mayo paraneoplastic evaluations

OBJECTIVE

To determine the proportion of true and false positives from paraneoplastic panels and effects on downstream testing/treatment.

METHODS

Using a retrospective cohort study design, we identified 500 consecutive patients with Mayo paraneoplastic autoantibody testing and performed chart abstraction. Paraneoplastic presentation types were categorized into probable, possible, and other by consensus. True positives were defined as a positive antibody titer with no other explanation found in addition to one of the following: syndrome known to be associated with the antibody, clinical improvement with treatment, and new malignancy. Comparisons of diagnostic testing and treatments between false and true positives were performed. Multivariable logistic regression was used to evaluate associations between patient-level factors and true positives.

RESULTS

The mean (SD) age of the population was 55.4 (17.1) years, and 55.4% were female, with 1.3 (1.2) years of follow-up. Of the 500 tests, 87 (17.4%, 95% confidence interval [CI] 14.1%-20.7%) were positive and 62 (71.3%, 95% CI 61.8%-80.8%) of these were false positives. Of those with a possible/other presentation (n = 369), 2 (0.5%, 95% CI 0.0%-1.0%) were true positives. CT of the chest (30.7% vs 11.8%, p ≤ 0.01) was performed more often in false positives than true negatives. Probable presentation type (odds ratio [OR] 57.9, 95% CI 12.5-268.0) and outpatient setting (OR 8.7, 95% CI 2.4-31.8) were associated with true-positive results.

CONCLUSION

Paraneoplastic tests result in a large proportion of false positives, particularly in those with clinical presentations that are not well established as paraneoplastic diseases. Future work should construct panels targeted to specific clinical presentations and ensure that tests are ordered in the appropriate clinical context.