Anti-TIF-1γ Antibody Detection Using a Commercial Kit vs In-House Immunoblot: Usefulness in Clinical Practice

Objectives

Anti-TIF-1γ autoantibody detection is important for cancer screening in patients with dermatomyositis. The gold standard for anti-TIF-1γ detection, immunoprecipitation, is only available from a few specialized laboratories worldwide, so commercial ELISA/immunoblot tests have emerged in recent years. To analyze their usefulness in diagnosing cancer-associated dermatomyositis, we compared Euroimmun Euroline profile with our previously validated in-house immunoblot assay with human recombinant TIF-1γ.

Methods

We included 308 adult patients from Hospital de la Santa Creu I Sant Pau and Vall Hebrón Hospital (Barcelona, Spain) tested for anti-TIF-1γ autoantibodies using the Euroline profile and an in-house immunoblot assay.

Results

A total of 27 anti-TIF-1γ were detected by the Euroline and 12 by the in-house assay. Fair agreement was observed between Euroline and the in-house immunoblot Cohen’s kappa 0.3163. Expected prevalence of anti-TIF-1γ autoantibodies was observed for the two methods for dermatomyositis and undifferentiated connective tissue diseases, but unexpectedly high prevalence of anti-TIF-1γ autoantibodies was detected by Euroline compared to the in-house immunoblot for other diseases (16.5% Euroline vs 0.8% in-house immunoblot, p<0.01). The in-house IB compared to Euroline more reliably detected cancer in patients with DM with anti-TIF-1γ antibodies (p=0.0014 vs p=0.0502 for in-house immunoblot vs Euroline).

Conclusion

We recommend using a second validated method to confirm Euroline-detected anti-TIF-1γ antibodies when the dermatomyositis diagnosis is not definitive. Furthermore, in the context of definite DM diagnosis with negative anti-TIF-1γ antibodies by Euroline and no other myositis specific antibody, is also recommendable to confirm by a second validated method.

The experience of a gout flare: a meta-synthesis of qualitative studies

AIMS

Gout flares are an important concern for people with gout and an understanding of patients' experiences with gout flares is central in developing meaningful outcome measures for clinical trials. This study aimed to systematically review and thematically synthesize the qualitative literature reporting the patient experience of gout flares, to inform the development of flare-specific outcome measures.

METHODS

MEDLINE, EMBASE, CINAHL Plus and PsycINFO electronic databases were searched in October 2019 to identify original qualitative research articles reporting on the patient experience of gout flares. Methodological quality of all included papers was assessed using the Critical Appraisal Skills Program (CASP) tool. Following data extraction, coding and synthesis was undertaken using reflexive thematic analysis.

RESULTS

Sixteen papers reporting the patient experience of gout flares were included. The majority of CASP criteria were met by most studies, indicating good methodological quality. Four predominant and overlapping themes were identified from the thematic analysis: gout flare characteristics (pain, swelling, location, duration and frequency); impact on function and activities of daily living (walking, housework and yard work, self-care, exercise and sports, driving, sleep); effects on social and family life (social participation, inability to plan, employment, dependency, relationships, intimacy); and psychological impact (boredom, irritability, fear, shame and embarrassment, isolation, financial worry, depression and anxiety).

CONCLUSIONS

Gout flares impact many aspects of patients' lives, including physical and psychological and social and family life. The patient experience of gout flares goes beyond what is routinely measured in research settings. Measurement and reporting methods that capture these aspects of patients' experiences with gout flares would provide more meaningful outcome measures in clinical trials of flare prevention.