Link Between Herbal Medicines for Arthritis and Liver Cancer Explained

Last week's articles on rheumatology topics in the major non-rheumatology journals

Genome-Wide Mutational Signatures of Aristolochic Acid and Its Application as a Screening ToolSci Transl Med, August 7, 2013

Several herbal medicines traditionally used to treat arthritis, gout, and inflammation, contain aristolochic acid (AA), which causes kidney failure and urothelial carcinoma of the upper urinary tract. Although the Food and Drug Administration has been sending warning letters since 2001, products containing AA, such as birthwort, are still sold on the Internet. Using whole-exome sequencing of tumor samples, researchers have found that AA causes cancer through a novel mechanism, an A:T → T:A transversion, which provide a signature that can identify cancers caused by AA.  For example, this transversion causes hepatocellular cancer previously attributed to hepatitis C. AA also caused a strikingly high rate of somatic mutations.

ALSO NEW THIS WEEK:Psoriasis Severity and the Prevalence of Major Medical Comorbidity:  A Population-Based StudyJAMA Dermatol, August 7, 2013

As the severity of psoriasis increases, so does the likelihood of comorbid disease, including more than a doubled risk for rheumatologic disorders, according to the first study that measured the severity of psoriasis objectively. (These authors assessed body surface involvement, while previous studies have used treatment as a proxy for severity.) In a population-based study of 9,035 patients in the United Kingdom, psoriasis severity was associated with higher prevalence of rheumatologic disease (adjusted odds ratio 2.04) as well as chronic pulmonary disease, diabetes mellitus, diabetes with systemic complications, mild liver disease, myocardial infarction, peptic ulcer disease, peripheral vascular disease, and renal disease, all of which had odds ratios between 1 and 2 . The authors urge all physicians to have a high index of suspicion for comorbidity when they see psoriasis.

Morphea in Adults and Children Cohort III Nested Case-Control Study-The Clinical Significance of Autoantibodies in Morphea
JAMA Dermatol, August 7, 2013

Evaluating the Clinical Utility of Autoantibodies in Morphea
JAMA Dermatol, August 7, 2013

Antinuclear antibodies (ANAs) and antihistone antibodies (ANHs) are prevalent among patients with morphea. Their clinical significance is limited to patients with linear morphea, where ANA, AHA, and anti-single-stranded DNA antibodies (ssDNA ab) are potential markers of disease severity. In linear morphea, AHA and ssDNA ab were associated with functional limitation, while ANA and ssDNA were associated with extensive body surface area involvement. Nonetheless, clinical examination to assess disease severity is still preferable to using any of these antibodies as surrogate markers, according to the study report and an editorial, although the results hint that as-yet undiscovered antibodies could ultimately prove useful. Meanwhile, clinicians should not order serial testing for antibodies to predict the outcome of morphea.