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Annual Review of Medicine Jan 2024The porphyrias are a group of rare diseases, each resulting from a defect in a different enzymatic step of the heme biosynthetic pathway. They can be broadly divided... (Review)
Review
The porphyrias are a group of rare diseases, each resulting from a defect in a different enzymatic step of the heme biosynthetic pathway. They can be broadly divided into two categories, hepatic and erythropoietic porphyrias, depending on the primary site of accumulation of heme intermediates. These disorders are multisystemic with variable symptoms that can be encountered by physicians in any specialty. Here, we review the porphyrias and describe their clinical presentation, diagnosis, and management. We discuss novel therapies that are approved or in development. Early diagnosis is key for the appropriate management and prevention of long-term complications in these rare disorders.
Topics: Humans; Porphyrias; Heme
PubMed: 37540847
DOI: 10.1146/annurev-med-042921-123602 -
Pharmacology & Therapeutics Aug 2023Protoporphyrin IX (PPIX) is an intermediate in the heme biosynthesis pathway. Abnormal accumulation of PPIX due to certain pathological conditions such as erythropoietic... (Review)
Review
Protoporphyrin IX (PPIX) is an intermediate in the heme biosynthesis pathway. Abnormal accumulation of PPIX due to certain pathological conditions such as erythropoietic protoporphyria and X-linked protoporphyria causes painful phototoxic reactions of the skin, which can significantly impact daily life. Endothelial cells in the skin have been proposed as the primary target for PPIX-induced phototoxicity through light-triggered generation of reactive oxygen species. Current approaches for the management of PPIX-induced phototoxicity include opaque clothing, sunscreens, phototherapy, blood therapy, antioxidants, bone marrow transplantation, and drugs that increase skin pigmentation. In this review, we discuss the present understanding of PPIX-induced phototoxicity including PPIX production and disposition, conditions that lead to PPIX accumulation, symptoms and individual differences, mechanisms, and therapeutics.
Topics: Humans; Endothelial Cells; Protoporphyrins; Protoporphyria, Erythropoietic; 5-Aminolevulinate Synthetase
PubMed: 37392940
DOI: 10.1016/j.pharmthera.2023.108487 -
Nature Reviews. Endocrinology Sep 2023A large body of preclinical and clinical data shows that the central melanocortin system is a promising therapeutic target for treating various metabolic disorders such... (Review)
Review
A large body of preclinical and clinical data shows that the central melanocortin system is a promising therapeutic target for treating various metabolic disorders such as obesity and cachexia, as well as anorexia nervosa. Setmelanotide, which functions by engaging the central melanocortin circuitry, was approved by the FDA in 2020 for use in certain forms of syndromic obesity. Furthermore, the FDA approvals in 2019 of two peptide drugs targeting melanocortin receptors for the treatment of generalized hypoactive sexual desire disorder (bremelanotide) and erythropoietic protoporphyria-associated phototoxicity (afamelanotide) demonstrate the safety of this class of peptides. These approvals have also renewed excitement in the development of therapeutics targeting the melanocortin system. Here, we review the anatomy and function of the melanocortin system, discuss progress and challenges in developing melanocortin receptor-based therapeutics, and outline potential metabolic and behavioural disorders that could be addressed using pharmacological agents targeting these receptors.
Topics: Humans; Melanocortins; Sexual Dysfunctions, Psychological; Obesity; Cachexia; Metabolic Diseases
PubMed: 37365323
DOI: 10.1038/s41574-023-00855-y -
Journal of the American Academy of... Dec 2023Erythropoietic protoporphyria and X-linked protoporphyria are rare genetic photodermatoses. Limited expertise with these disorders among physicians leads to diagnostic...
Erythropoietic protoporphyria and X-linked protoporphyria are rare genetic photodermatoses. Limited expertise with these disorders among physicians leads to diagnostic delays. Here, we present evidence-based consensus guidelines for the diagnosis, monitoring, and management of erythropoietic protoporphyria and X-linked protoporphyria. A systematic literature review was conducted, and reviewed among subcommittees of experts, divided by topic. Consensus on guidelines was reached within each subcommittee and then among all members of the committee. The appropriate biochemical and genetic testing to establish the diagnosis is reviewed in addition to the interpretation of results. Prevention of symptoms, management of acute phototoxicity, and pharmacologic and nonpharmacologic treatment options are discussed. The importance of ongoing monitoring for liver disease, iron deficiency, and vitamin D deficiency is discussed with management guidance. Finally, management of pregnancy and surgery and the safety of other therapies are summarized. We emphasize that these are multisystemic disorders that require longitudinal monitoring. These guidelines provide a structure for evidence-based diagnosis and management for practicing physicians. Early diagnosis and management of these disorders are essential, particularly given the availability of new and emerging therapies.
Topics: Humans; Dermatitis, Phototoxic; Genetic Diseases, X-Linked; Liver Diseases; Protoporphyria, Erythropoietic; Practice Guidelines as Topic
PubMed: 36041558
DOI: 10.1016/j.jaad.2022.08.036 -
Dermatologie (Heidelberg, Germany) Jun 2024Porphyrias are predominantly genetic metabolic disorders caused by dysregulation of specific enzymes in porphyrin-heme biosynthesis. The enzymatic dysfunction leads to... (Review)
Review
Porphyrias are predominantly genetic metabolic disorders caused by dysregulation of specific enzymes in porphyrin-heme biosynthesis. The enzymatic dysfunction leads to formation and excretion of intermediate metabolic products in the form of porphyrins and/or their precursors δ‑aminolevulinic acid and porphobilinogen, which have cyto- and tissue-toxic properties. Clinically, porphyrias are extremely diverse, with symptoms ranging from skin changes on light-exposed areas of the body to potentially life-threatening neurovisceral attacks. Biochemical tests in urine, blood and stool are used for diagnosis, which can be supplemented by molecular genetic analyses. Treatment of the various forms of porphyria is complex and often requires close interdisciplinary cooperation between different medical specialties.
PubMed: 38902527
DOI: 10.1007/s00105-024-05370-3 -
Gastroenterology Jan 2024
Topics: Humans; Protoporphyria, Erythropoietic; Photosensitivity Disorders; Abdominal Pain; Protoporphyrins
PubMed: 37579823
DOI: 10.1053/j.gastro.2023.07.028