A genome-wide meta-analysis of palmoplantar pustulosis implicates Th2 responses and cigarette smoking in disease pathogenesis (2024)

Type of publication:
Journal article [preprint]

Author(s):
Hernandez-Cordero A.; Thomas L.; Smail A.; Lim Z.Q.; Saklatvala J.R.; Chung R.; Curtis C.J.; Baum P.; Visvanathan S.; Burden A.D.; Cooper H.L.; Dunnill G.; Griffiths C.E.M.; Levell N.J.; Parslew R.; Reynolds N.J.; Wahie S.; Warren R.B.; Wright A.; Simpson M.; Hveem K.; Barker J.N.; Dand N.; Loset M.; Smith C.H.; Capon F.; Abraham T.; Ali M.; August S.; Baudry D.; Becher G.; Bewley A.; Brown V.; Cornelius V.; Ghaffar S.; Ingram J.; Kavakleiva S.; *Kelly S.; Khorshid M.; Lachmann H.; Ladoyanni E.; McAteer H.; McKenna J.; Meynell F.; Patel P.; Pink A.; Powell K.; Pushparajah A.; Sinclair C.; Wachsmuth R.;

Citation:
medRxiv. (no pagination), 2024. Date of Publication: 17 Jan 2024.

Abstract:
Background: Palmoplantar pustulosis (PPP) is an inflammatory skin disorder that mostly affects smokers and manifests with painful pustular eruptions on the palms and soles. While 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. Objective(s): To identify genetic determinants of PPP and investigate whether cigarette smoking contributes to disease pathogenesis. Method(s): We performed a genome-wide association meta-analysis of three 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 resulting association signals. We 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. Result(s): 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<5X10-6) susceptibility regions, including the IL4/IL13 interval. Accordingly, we demonstrated a significant genetic correlation between PPP and Th2-mediated diseases like atopic dermatitis and ulcerative colitis. We also found that genes mapping to PPP-associated intervals were preferentially expressed in dendritic cells and enriched for T-cell activation pathways. Finally, we undertook a Mendelian randomization analysis, which supported a causal role of cigarette smoking in PPP. Conclusion(s): The first genome-wide association study of PPP points to a pathogenic role for deregulated Th2 responses and cigarette smoking.

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Clozapine toxicity: a cautionary palliative care tale (2020)

Type of publication:
Journal article

Author(s):
*Macfarlane, Michael; Shahab, Julita; *Willis, Derek

Citation:
BMJ Supportive & Palliative Care; Sep 2020; vol. 10 (no. 3); p. 312-313

Abstract:
OBJECTIVE: This case report presents an unusual case of clozapine toxicity secondary to reduced smoking habit mimicking a patient approaching end of life. METHODS: It is a cautionary tale for palliative care specialists, perhaps unaware of the effect of cigarette smoke on metabolism of this antipsychotic, to be aware of. RESULTS: Following specialist advice and change of antipsychotic medication, this patient's condition improved to the point that he was discharged from the hospice. CONCLUSION: Palliative care specialists should be aware that reducing cigarette consumption can alter metabolism of clozapine, potentially causing drug accumulation and toxicity with features which mimic deterioration towards end of life. Specialist advice should be sought in such a situation.