The effects of cholecalciferol and afamelanotide on vitamin D levels in erythropoietic protoporphyria: a multicentre cohort study.

BACKGROUND: Patients with erythropoietic protoporphyria experience lifelong painful photosensitivity resulting in a lack of sunlight exposure. Previous studies have shown that 47-63% of patients with EPP suffer from vitamin D deficiency and a high prevalence of osteoporosis. An effective treatment for EPP has been available since 2016: the α-melanocyte stimulating hormone analogue afamelanotide. So far, studies on vitamin D levels in EPP have only investigated patients who have not been treated with afamelanotide. OBJECTIVES: To investigate the effects of afamelanotide treatment on vitamin D levels in EPP. METHODS: A multicentre observational cohort study in adults with EPP from the Erasmus Medical Centre, the Netherlands, and the University Hospital Düsseldorf, Germany, was carried out. Routinely collected vitamin D levels between 2005 and 2021 were used for analysis. Patient exposure to cholecalciferol or afamelanotide was categorized into four treatment groups: untreated, cholecalciferol, afamelanotide and combined treatment. A linear mixed model for longitudinal data was applied to measure the effect of the treatment groups compared with the untreated groups on vitamin D levels. RESULTS: A total of 230 patients and 1774 vitamin D measurements were included. The prevalence of vitamin D deficiency and severe deficiency remained high despite afamelanotide treatment (< 50 nmol L-1 in 71.8% of patients and < 30 nmol L-1 in 48.1%, respectively). Afamelanotide treatment alone did not lead to a significant average increase in vitamin D levels [ß = 0.5, 95% confidence interval (CI) -3.2 to 4.2]. In contrast, cholecalciferol and combined therapy with afamelanotide led to a significant increase in vitamin D levels [ß = 11.6 (95% CI 7.2-15.9) and ß = 15.2 (95% CI 12.3-18.1), respectively]. CONCLUSIONS: Cholecalciferol remains essential for the treatment of vitamin D deficiency in EPP, irrespective of new treatment options like afamelanotide. Afamelanotide treatment did not affect vitamin D levels. We suggest that future guidelines include continuous monitoring of vitamin D and a prescription for cholecalciferol in all patients with EPP, including those treated with afamelanotide.

Erythropoietic protoporphyria (EPP) is a rare inherited condition. People with EPP experience severe pain after their skin has been exposed to sunlight. To avoid this severe pain, people with EPP avoid going out in the sun by limiting outdoor activities or by wearing protective clothing. As sunlight is needed for our skin to produce vitamin D, approximately half of people with EPP in Europe do not have enough of it. In 2016, a new treatment called afamelanotide (SCENESSE®) became available, which allows people with EPP to go outside and expose themselves to sunlight longer without pain. In this study, we looked at how afamelanotide and vitamin D supplements affect vitamin D levels in people with EPP. We included information from patients treated in Rotterdam in the Netherlands and Düsseldorf in Germany and analysed levels of vitamin D in their blood. We also examined electronic patient files and collected questionnaires on the use of vitamin D supplements. In total, information from 230 patients was included. We found that afamelanotide alone did not raise vitamin D levels, but in combination with vitamin D supplements, vitamin D levels did go up. Even though afamelanotide is now available, our findings suggest that people with EPP may need more time to adapt to an outdoor lifestyle, after being conditioned to avoid sunlight since their childhood. Overall, our study demonstrates that vitamin D supplements remain crucial for people with EPP, with or without afamelanotide treatment.

Fatigue in patients with inflammatory bowel disease is associated with distinct differences in immune parameters.

BACKGROUND: Although it is well recognized that fatigue is an important problem in many of the quiescent inflammatory bowel disease (IBD) patients, it is unknown whether the immune status is different in fatigued versus non-fatigued patients. In this study, we contrasted various characteristics of the immune system in fatigued against non-fatigued patients with IBD in clinical remission. PATIENTS AND METHODS: Patients with IBD in clinical remission were phenotyped according to the Montreal classification, and the checklist individual strength-fatigue (CIS-fatigue) was used to assess fatigue (CIS-fatigue ≥ 35). Flow cytometry on peripheral blood samples was used to investigate differences in leukocyte subsets. The expression of various cytokines was determined in stimulated whole blood and serum samples using enzyme-linked immunosorbent assay. Differences between fatigued and non-fatigued patients with IBD were assessed. RESULTS: In total, 55 patients were included in the fatigue group (FG) and 29 patients in the non-fatigue group (NFG). No differences in demographic and clinical characteristics were observed between the groups. Flow cytometry data showed a significantly lower percentage of monocytes (p = 0.011) and a higher percentage of memory T-cells (p = 0.005) and neutrophils (p = 0.033) in the FG compared with the NFG. Whole blood stimulation showed increased TNF-α (p = 0.022) and IFN-γ (p = 0.047) in the FG. The median serum level was significantly higher for IL-12 (p < 0.001) and IL-10 (p = 0.005) and lower for IL-6 (p = 0.002) in the FG compared with NFG. CONCLUSION: Significant differences in immune profile between fatigued and non-fatigued patients with IBD in clinical remission were found, which point out to a chronically active and Th1-skewed immune system in patients with fatigue. Whether these immune differences are directly involved in the fatigue complaints via immune-to-brain communication pathways remains to be determined. As such, further exploration of the underlying immune effects associated with fatigue is warranted to determine potential treatment options.