From Epidemiology and Genetics to Diagnostics, Outcome Measures, and Novel Treatments in Autoimmune Bullous Diseases

Measuring of quality of life in autoimmune blistering disorders in Poland. Validation of disease - specific Autoimmune Bullous Disease Quality of Life (ABQOL) and the Treatment Autoimmune Bullous Disease Quality of Life (TABQOL) questionnaires

PURPOSE

Autoimmune bullous dermatoses (AIBD) are rare, severe diseases resulting from some antibodies activity against the different adhesion structures within the skin and/or mucosa. Few studies investigated quality of life (QOL) in AIBD by generic and dermatology-specific instruments, all reporting strong impact on QOL. Recently, disease-specific measurement tools have been developed: Autoimmune Bullous Disease Quality of Life (ABQOL) and Treatment of Autoimmune Bullous Disease Quality of Life (TABQOL) questionnaires. The aim of this study was to test the reliability and validity of ABQOL and TABQOL by developing the first foreign language versions and to evaluate ABQOL and TABQOL in Polish patients.

MATERIAL AND METHODS

The study enrolled 80 patients from the tertiary referral center for AIBD at the outpatient clinic or on admission to the hospital. Sixty six patients completed the 17-item questionnaires of each ABQOL and TABQOL at day 0 and after 5-7 days. Both questionnaires were translated into Polish according to protocol.

RESULTS

The internal consistency and test-retest reliability were high (Cronbach α=0.95 for ABQOL, α=0.87 for TABQOL), (R=0.98 for ABQOL, R=0.86 for TABQOL). In convergent validity, the correlation of ABQOL and TABQOL was strong (R=0.81), but low with objective disease activity scales. The strongest impact of AIBD on QOL has been observed in flares and in patients with the onset below 70 years of age. The patients with bullous pemphigoid had the highest QOL compared to other AIBD patients.

CONCLUSIONS

The ABQOL and TABQOL are reliable and valid instruments for the assessment of QOL in AIBD.

Outcome measures for autoimmune blistering diseases

Outcome measures are crucial in assessing an autoimmune blistering disease's (AIBD) severity as well as its impact on the patient's quality of life (QOL). The standardization of AIBD outcome measures is pivotal to accurately monitor the patient and to pool results from randomized controlled trials for meta-analysis, and thereby provide knowledge of the optimal AIBD therapies. In the past decade, several AIBD severity outcome measures have been developed and validated. For pemphigus severity, the Pemphigus Disease Area Index (PDAI) developed by the International Pemphigus Definitions Group was shown to be the most superior, followed by the Autoimmune Bullous Skin Disorder Intensity Score (ABSIS) by the German group. For bullous pemphigoid severity, the Bullous Pemphigoid Disease Area Index (BPDAI) was shown to be an accurate and valid measure. To quantify the burden of AIBD and its treatments on QOL, the Autoimmune Bullous Disease Quality of Life (ABQOL) and the Treatment of Autoimmune Bullous Disease Quality of Life (TABQOL) were also developed, validated, and are now being validated in multiple languages and cultures.

Psoriasis and autoimmunity

Psoriasis is one of the most common chronic inflammatory human skin diseases. Though clinically well characterized, the exact etiological and pathogenic mechanisms are still not known in detail. Current knowledge indicates distinct overlap to other inflammatory as well as autoimmune disorders. However, the one or more relevant autoantigens could not be characterized so-far. On the other side, several autoimmune diseases were shown to be associated with psoriasis. In addition, serological autoimmune phenomena, namely diverse circulating specific autoantibodies could be demonstrated in the past. A matter of current debate is if psoriasis is a primary autoimmune disease or secondarily evolving into autoimmunity as seen in other chronic inflammatory diseases. Related to this aspect is the concept of autoinflammation versus autoimmunity where psoriasis shares mechanisms of both entities. Though T-cells remain among the most important cellular players in the pathogenesis of psoriasis and current therapeutic strategies successfully target these cells or their products irrespective of these concepts, autoimmunity if relevant will add to the treatment armamentarium by using protective and prophylactic antigen-specific modalities.