Chemical exposures and demographic associations in cutaneous T-cell lymphoma: a large single institution physician validated cohort study

Cutaneous T-cell lymphomas (CTCL) are a rare group of T-cell neoplasms which infiltrate the skin and can result in substantial morbidity and mortality. Risk factors for CTCL are still poorly understood though recent studies suggest chemical exposures may play a role in its development. To further characterize patient-centered risk factors for CTCL, especially compared with matched controls, we performed one of the largest prospective cohort survey studies to date to examine patient-reported exposures and health-related quality of life (HRQoL) in association with concurrent clinical disease characteristics. Patient demographics, lifestyle factors, and chemical exposures were collected via clinical data and surveys. Descriptive statistics, ANOVA, Chi-square tests and t tests were utilized to compare patient-reported exposures and HRQoL in patients with CTCL versus matched healthy controls (HC). Statistically significant differences were identified between patients and HC in terms of race (non-white race 22.4% in CTCL patients vs. 18.8% in HC, P = 0.01), and education level (high school or less 41.6% in CTCL patients vs. 14.3% in HC, P = 0.001), but not with Fitzpatrick skin type (P = 0.11) or smoking status (P = 0.28). Notably, 36.0% of the CTCL patients reported exposures to chemicals, a near threefold increased percentage when compared to HC (12.9%). Among various chemical exposures, 27.0% of the CTCL patients specifically reported industrial chemical exposure, a more than two-fold increased percentage when compared to HC (12.9%). Itch and pain were significantly associated with skin disease severity (as evaluated by CTCL-specific mSWAT score) in advanced stage disease (stages IIB-IVB) (r = 0.48 and 0.57, P < 0.05). Itch and body mass index (BMI) were weakly associated with skin disease severity in early-stage disease (stages IA-IIA) (r = 0.27 and 0.20, P < 0.05).

Gut microbiota analyses of cutaneous T-cell lymphoma patients undergoing narrowband ultraviolet B therapy reveal alterations associated with disease treatment

Recent studies have shown a close relationship between cutaneous T-cell lymphoma (CTCL) and its microbiome. CTCL disease progression is associated with gut dysbiosis and alterations in bacterial taxa parallel those observed in immunologically similar atopic dermatitis. Moreover, the microbial profile of lesional skin may predict response to narrowband ultraviolet B (nbUVB), a common skin-directed therapy. However, the relationship between the gut microbiome, an immunologically vital niche, and nbUVB remains unexplored in CTCL. Herein, we performed 16S rRNA sequencing and PICRUSt2 predictive metagenomics on DNA extracted from stool swabs of 13 CTCL patients treated with nbUVB, 8 non-treated patients, and 13 healthy controls. Disease response was assessed with modified Severity Weighted Assessment Tool (mSWAT); of nbUVB-treated patients, 6 improved (decreased mSWAT), 2 remained stable, and 5 worsened (increased mSWAT). Protective commensal bacteria including Lactobacillaceae and Erysipelatoclostridiaceae were significantly less abundant in CTCL patients compared to controls. With treatment, the CTCL gut microbiome exhibited decreased phylogenetic diversity and lower relative abundance of pro-inflammatory Sutterellaceae. Sutterellaceae was also significantly more abundant in patients who worsened, and Eggerthellaceae and Erysipelotrichaceae trended higher in patients who improved. Finally, PICRUSt2 functional predictions based on shifts in abundance of bacterial sequences repeatedly identified alterations in inositol degradation, which plays a key role in host immunomodulation, including inositol phospholipid signaling relevant to T-cell survival and proliferation. Our results bolster the paradigm of gut dysbiosis in CTCL and its functional implications in disease pathogenesis, and further delineate bacterial taxa associated with nbUVB response and with nbUVB treatment itself.