Overutilization and underutilization of autoantibody tests in patients with suspected autoimmune disorders

The undue influence of genetic information on senior medical students' treatment decisions

BACKGROUND

Knowledge of the genetic basis of health conditions can influence how the public perceives their own and others' health. When there are known genetic associations for such conditions, genetic essentialist biases facilitate deterministic thinking and an over-emphasis of genetic causality. This study investigates the role that genetic essentialist biases play in medical decision-making.

METHODS

Senior postgraduate medical students (N = 102) read a scenario in which a patient presents with gastroenterological symptoms. Half of the students were told that the patient tested positive for HLADQ2 - a gene implicated in, but not deterministic of, coeliac disease. The other half received no genetic information. Students were assessed on their recommendations for investigation and management using a multiple-choice questionnaire. Twenty-two of these students participated in a qualitative follow-up which used focus groups and semi-structured interviews to explore the reasoning behind students' responses.

RESULTS

Management recommendations differed between the two groups, with those receiving genetic information more likely to recommend a gluten free diet. Recommendations for further investigation did not differ significantly between groups. Interviews suggested that these findings arose despite the students' good understanding of the common non-deterministic nature of genes, such as HLADQ2.

CONCLUSION

Differences in management recommendations suggest that the inclusion of genetic information unduly biased students towards a premature diagnosis of a serious health condition, coeliac disease. Follow-up interviews introduced the possibility that observed manipulation-based differences may have been based on anticipated expectations of examiners, rather than perceived future clinical practice. Based on the present results it is unclear whether intentional exam-taking strategies fully account for medical students' decisions, or if they contribute in addition to the activation of genetic essentialist biases. Further research in clinical settings may ascertain whether genetic essentialist biases would truly influence medical student and doctors within their clinical practice environment.

Evaluation of Antinuclear Antibody and Subserology Reflex Testing for the Diagnosis of Systemic Autoimmune Rheumatic Disorders in an Academic Teaching Hospital

OBJECTIVE

The aim of this study was to examine appropriate utilization of antinuclear antibody (ANA) screening tests with follow-up subserology tests (reflex testing) for diagnosing systemic autoimmune rheumatic disorder (SARD).

METHODS

We conducted a retrospective chart review of 3003 SARD-test orders at an academic teaching hospital from January to December 2019. Testing patterns were categorized as American College of Rheumatology (ACR)-recommended reflex testing, panel testing, or single subserology testing. We described testing patterns, assessed their diagnostic accuracy, and explored factors associated with reflex testing.

RESULTS

Reflex testing accounted for 79.7% of SARD test-ordering, whereas improper testing (panel or single subserology) accounted for the other 20.3%. Reflex testing was associated with significantly more SARD diagnoses than improper testing (P = .004). Testing patterns were significantly associated with race/ethnicity (P = .008), with reflex testing being less frequent than improper testing in Hispanics and Whites.

CONCLUSION

In summary, one-fifth (20.3%) of testing patterns for suspected SARD did not follow the ACR-recommended guidelines for using reflex testing. Use of reflex testing was associated with an increased frequency of SARD diagnosis.

Presence of anti-nuclear antibody associated with worse clinical outcomes of anti-NMDAR encephalitis

Purpose

Systemic autoantibodies are important for the diagnosis of autoimmune diseases, but their roles in anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis are unknown. The purpose of our study is to investigate the characteristics and a prognosis of anti-NMDAR encephalitis with the prevalence of autoantibodies.

Methods

Systemic autoantibodies were evaluated in 64 patients with anti-NMDAR encephalitis and 14 patients with autoimmune encephalitis with other forms. Then, according to systemic autoantibodies, patients with anti-NMDAR encephalitis were divided into an anti-nuclear antibody (ANA) positive group and an ANA negative group. The clinical outcome was assessed by a modified Rankin score at 12 months after the disease onset.

Results

A total of 64 patients with anti-NMDAR encephalitis were enrolled, of which 28.13% (18/64) were positive for ANA. The titers of a positive anti-NMDAR antibody in CSF (p = 0.041) and serum (p = 0.031) in the ANA-positive group were significantly higher than the ANA-negative group. Patients with ANA positive than those with ANA negative showed lower rates of headache (p = 0.047) and speech disorder (p = 0.049). The presence of ANA was associated with a worse clinical outcome at 12 months (p = 0.043).

Conclusion

ANA was prevalent in patients with anti-NMDAR encephalitis, and associated with a worse prognosis and impaired neurological recovery.