Low-Dose Vitamin D3 Supplementation Does Not Affect Natural Regulatory T Cell Population but Attenuates Seasonal Changes in T Cell-Produced IFN-γ: Results From the D-SIRe2 Randomized Controlled Trial

Background

Seasonal variations have been reported for immune markers. However, the relative contributions of sunlight and vitamin D variability on such seasonal changes are unknown.

Objective

This double-blind, randomized, placebo-controlled trial tested whether daily 400 IU vitamin D₃ supplementation affected short-term (12 weeks) and long-term (43 weeks) natural regulatory T cell (nTreg) populations in healthy participants.

Design

62 subjects were randomized equally to vitamin D versus placebo in March and assessed at baseline, April (4w), June (12w), September (25w) and January (43w). Circulating nTregs, ex vivo proliferation, IL-10 and IFN-γ productions were measured. Vitamin D metabolites and sunlight exposure were also assessed.

Results

Mean serum 25-hydroxyvitamin D (25(OH)D) increased from 35.8(SD 3.0) to 65.3(2.6) nmol/L in April and remained above 75 nmol/L with vitamin D supplementation, whereas it increased from 36.4(3.2) to 49.8(3.5) nmol/L in June to fall back to 39.6(3.5) nmol/L in January with placebo. Immune markers varied similarly between groups according to the season, but independently of 25(OH)D. For nTregs, the mean (%CD3⁺CD4⁺CD127^lo cells (SEM)) nadir observed in March (2.9(0.1)%) peaked in September at 4.0(0.2)%. Mean T cell proliferation peaked in June (33156(1813) CPM) returning to the nadir in January (17965(978) CPM), while IL-10 peaked in June and reached its nadir in September (median (IQR) of 262(283) to (121(194) pg/ml, respectively). Vitamin D attenuated the seasonal increase in IFN-γ by ~28% with mean ng/ml (SEM) for placebo vs vitamin D, respectively, for April 12.5(1.4) vs 10.0(1.2) (p=0.02); June 13.9(1.3) vs 10.2(1.7) (p=0.02) and January 7.4(1.1) vs 6.0(1.1) (p=0.04).

Conclusions

Daily low dose Vitamin D intake did not affect the nTregs population. There were seasonal variation in nTregs, proliferative response and cytokines, suggesting that environmental changes influence immune response, but the mechanism seems independent of vitamin D status. Vitamin D attenuated the seasonal change in T cell-produced IFN-γ, suggesting a decrease in effector response which could be associated with inflammation.

Clinical Trial Registration

https://www.isrctn.com, identifier (ISRCTN 73114576).

Diagnostic Criteria of Ulcerative Pyoderma Gangrenosum: A Delphi Consensus of International Experts

Importance

Pyoderma gangrenosum is a rare inflammatory skin condition that is difficult to diagnose. Currently, it is a "diagnosis of exclusion," a definition not compatible with clinical decision making or inclusion for clinical trials.

Objective

To propose and validate diagnostic criteria for ulcerative pyoderma gangrenosum.

Evidence Review

Diagnostic criteria were created following a Delphi consensus exercise using the RAND/UCLA Appropriateness Method. The criteria were validated against peer-reviewed established cases of pyoderma gangrenosum and mimickers using k-fold cross-validation with methods of multiple imputation.

Findings

Delphi exercise yielded 1 major criterion-biopsy of ulcer edge demonstrating neutrophilic infiltrate-and 8 minor criteria: (1) exclusion of infection; (2) pathergy; (3) history of inflammatory bowel disease or inflammatory arthritis; (4) history of papule, pustule, or vesicle ulcerating within 4 days of appearing; (5) peripheral erythema, undermining border, and tenderness at ulceration site; (6) multiple ulcerations, at least 1 on an anterior lower leg; (7) cribriform or "wrinkled paper" scar(s) at healed ulcer sites; and (8) decreased ulcer size within 1 month of initiating immunosuppressive medication(s). Receiver operating characteristic analysis revealed that 4 of 8 minor criteria maximized discrimination, yielding sensitivity and specificity of 86% and 90%, respectively.

Conclusions and Relevance

This Delphi exercise produced 1 major criterion and 8 minor criteria for the diagnosis of ulcerative pyoderma gangrenosum. The criteria may serve as a guideline for clinicians, allowing for fewer misdiagnoses and improved patient selection for clinical trials.

Basal cell carcinoma

INTRODUCTION

Basal cell carcinoma (BCC) is the most common form of skin cancer, predominantly affecting the head and neck, and can be diagnosed clinically in most cases. Metastasis of BCC is rare, but localised tissue invasion and destruction can lead to morbidity. Incidence of BCC increases markedly after the age of 40 years, but incidence in younger people is rising, possibly as a result of increased sun exposure.

METHODS AND OUTCOMES

We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of interventions on treatment response/recurrence (within 1 year of therapy) in people with basal cell carcinoma? What are the effects of interventions on long-term recurrence (a minimum of 2 years after treatment) in people with basal cell carcinoma? We searched: Medline, Embase, The Cochrane Library, and other important databases up to December 2009 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).

RESULTS

We found 16 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

CONCLUSIONS

In this systematic review we present information relating to the effectiveness and safety of the following interventions: cryotherapy/cryosurgery, curettage and cautery/electrodesiccation, fluorouracil, imiquimod 5% cream, photodynamic therapy, and surgery (conventional or Mohs' micrographic surgery).

Basal cell carcinoma

INTRODUCTION

Basal cell carcinoma (BCC) is the most common form of skin cancer, predominantly affecting the head and neck, and can be diagnosed clinically in most cases. Metastasis of BCC is rare, but localised tissue invasion and destruction can lead to morbidity. Incidence of BCC increases markedly after the age of 40 years, but incidence in younger people is rising, possibly as a result of increased sun exposure.

METHODS AND OUTCOMES

We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of interventions on treatment response/recurrence (within 1 year of therapy) in people with basal cell carcinoma? What are the effects of interventions on long-term recurrence (a minimum of 2 years after treatment) in people with basal cell carcinoma? We searched: Medline, Embase, The Cochrane Library and other important databases up to February 2007 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).

RESULTS

We found 11 systematic reviews, RCTs or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

CONCLUSIONS

In this systematic review we present information relating to the effectiveness and safety of the following interventions: Cryotherapy/cryosurgery, curettage and cautery/electrodesiccation, fluorouracil, imiquimod 5% cream, photodynamic therapy, and surgery (conventional or Moh's micrographic surgery).

Nitric oxide is generated on the skin surface by reduction of sweat nitrate

Nitric oxide (NO) is known to be synthesized by mammalian cells from L-arginine by a group of NO synthase enzymes. We now show that NO is generated from human skin and propose a different mechanism of production. Whereas enzymatic NO synthesis is inhibited by monomethyl L-arginine, this arginine analog, when infused into the brachial artery at concentrations sufficient to inhibit endothelial NO synthase activity, has little effect on hand skin NO production. Hand skin NO production is increased by topical acidification of the skin surface and greatly increased by the addition of nitrite solutions. We propose that NO generation from skin derives from sweat nitrite (the concentration of which was found to average 3.4 microM in six subjects) due to chemical reduction consequent to the acidic nature of sweat. Sweat contains nitrate in appreciable amounts, and skin commensal bacteria can synthesize nitrate reductase enzyme. Patients on long-term tetracycline antibiotics showed significantly reduced skin NO synthesis, although topical antiseptic and antibiotics had little effect on NO generation in the short-term. We propose that NO generation from skin is dependent on bacterial nitrate reduction to nitrite and subsequent reduction by acidification. We speculate that this has a physiologic role in the inhibition of infection by pathogenic fungi and other susceptible microorganisms and may affect cutaneous T-cell function, keratinocyte differentiation, and skin blood flow.

Discoid lupus erythematosus in an X-linked cytochrome-positive carrier of chronic granulomatous disease

A 13-year-old female presented with photosensitivity, recurrent aphthous ulcers and discoid lupus erythematosus (DLE)-like skin lesions. These symptoms have been linked to the carrier status of chronic granulomatous disease (CGD). Neutrophil (PMN) function was investigated by nitroblue tetrazolium reduction test and chemiluminescence. A severe impairment of PMN oxidative burst activity was revealed in spite of supranormal levels of cytochrome b245. Glucose-6-phosphate dehydrogenase activity was deficient. Her mother and two sisters also showed reduced PMN function. These findings are consistent with a cytochrome positive X-linked form of CGD with variable lyonization. DLE in association with the carrier status of this CGD variant has not been reported previously.