A genome-wide meta-analysis of palmoplantar pustulosis implicates TH2 responses and cigarette smoking in disease pathogenesis.

BACKGROUND: Palmoplantar pustulosis (PPP) is an inflammatory skin disorder that mostly affects smokers and manifests with painful pustular eruptions on the palms and soles. Although the disease can present with concurrent plaque psoriasis, TNF and IL-17/IL-23 inhibitors show limited efficacy. There is therefore a pressing need to uncover PPP disease drivers and therapeutic targets. OBJECTIVES: We sought to identify genetic determinants of PPP and investigate whether cigarette smoking contributes to disease pathogenesis. METHODS: We performed a genome-wide association meta-analysis of 3 North-European cohorts (n = 1,456 PPP cases and 402,050 controls). We then used the scGWAS program to investigate the cell-type specificity of the association signals. We also undertook genetic correlation analyses to examine the similarities between PPP and other immune-mediated diseases. Finally, we applied Mendelian randomization to analyze the causal relationship between cigarette smoking and PPP. RESULTS: We found that PPP is not associated with the main genetic determinants of plaque psoriasis. Conversely, we identified genome-wide significant associations with the FCGR3A/FCGR3B and CCHCR1 loci. We also observed 13 suggestive (P < 5 × 10-6) susceptibility regions, including the IL4/IL13 interval. Accordingly, we demonstrated a significant genetic correlation between PPP and TH2-mediated diseases such as atopic dermatitis and ulcerative colitis. We also found that genes mapping to PPP-associated intervals were preferentially expressed in dendritic cells and often implicated in T-cell activation pathways. Finally, we undertook a Mendelian randomization analysis, which supported a causal role of cigarette smoking in PPP. CONCLUSIONS: The first genome-wide association study of PPP points to a pathogenic role for deregulated TH2 responses and cigarette smoking.

Primary cutaneous acral CD8+ T-cell lymphoma of the ear: A case report.

Primary cutaneous acral CD8+ T-cell lymphoma (TCL) is a rare, distinct type of cutaneous TCL. Despite its worrisome histological appearance it has a benign clinical course. It is therefore important to recognize this as a distinct entity from other more aggressive CD8+ lymphomas, for which the management is very different.

Is tocilizumab a potential therapeutic option for refractory unicentric Castleman disease?

Castleman disease is a rare lymphoproliferative disorder with 2 distinctly defined clinical forms. While multicentric Castleman disease (UCD) poses a potential therapeutic challenge, unicentric variant has historically been considered curable with surgical resection. Hence, little is known to guide management of patients with UCD, refractory to surgical resection and combination chemotherapy. We present a case of a patient, negative for HIV and HHV-8, who had an unsuccessful surgical intervention and no response to radiotherapy and chemotherapy. He had severe paraneoplastic pemphigus and was treated with tocilizumab, an anti-interleukin-6 receptor monoclonal antibody that has demonstrated good response rates in multicentric Castleman disease but demonstrated no clinical response despite 2 months of treatment. Our report is the first to describe a lack of response to tocilizumab in the rare setting of refractory UCD and discuss potential for distinct disease biology.

Angiolymphoid hyperplasia with eosinophilia successfully treated with oral steroids.

Angiolymphoid hyperplasia with eosinophilia is a rare benign vascular lesion most commonly affecting the head and neck region. This article reports a case of a 26-year-old white woman with rapidly enlarging nodules of the upper lip and cheek treated successfully with oral corticosteroids and cetirizine. Morbidity and cosmetic deformity associated with radical surgery to the face and possible consequences of radiation treatment were avoided. There were no long-term complications.

Loss-of-function mutations of an inhibitory upstream ORF in the human hairless transcript cause Marie Unna hereditary hypotrichosis.

Marie Unna hereditary hypotrichosis (MUHH) is an autosomal dominant form of genetic hair loss. In a large Chinese family carrying MUHH, we identified a pathogenic initiation codon mutation in U2HR, an inhibitory upstream ORF in the 5' UTR of the gene encoding the human hairless homolog (HR). U2HR is predicted to encode a 34-amino acid peptide that is highly conserved among mammals. In 18 more families from different ancestral groups, we identified a range of defects in U2HR, including loss of initiation, delayed termination codon and nonsense and missense mutations. Functional analysis showed that these classes of mutations all resulted in increased translation of the main HR physiological ORF. Our results establish the link between MUHH and U2HR, show that fine-tuning of HR protein levels is important in control of hair growth, and identify a potential mechanism for preventing hair loss or promoting hair removal.