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Ophthalmic Plastic and Reconstructive...Exogenous ochronosis refers to accumulation of homogentisic acid metabolites in tissues, manifesting as pigmentation of affected tissues. Phenolic compounds are most...
Exogenous ochronosis refers to accumulation of homogentisic acid metabolites in tissues, manifesting as pigmentation of affected tissues. Phenolic compounds are most commonly implicated, including hydroquinone, quinine, phenol, resorcinol, mercury, and picric acid. The affected connective tissues exhibit brownish discoloration when heavily pigmented and the histopathological appearance is characteristic with "banana-shaped" ochre-colored pigment deposits. Herein, the authors describe a rare case of exogenous ochronosis involving the conjunctiva, sclera and skin, as a result of chronic use of Teavigo (94% epigallocatechin gallate), a polyphenol compound with postulated antioxidant and antiapoptotic activity.
Topics: Humans; Ochronosis; Alkaptonuria; Skin; Pigmentation Disorders
PubMed: 37010051
DOI: 10.1097/IOP.0000000000002395 -
Pediatric Nephrology (Berlin, Germany) Sep 2023Although hyperuricemia is a widely studied condition with well-known effects on the kidneys, hypouricemia is usually considered a biochemical abnormality of no clinical...
BACKGROUND
Although hyperuricemia is a widely studied condition with well-known effects on the kidneys, hypouricemia is usually considered a biochemical abnormality of no clinical significance despite the fact that it can be a sign or major finding of serious metabolic or genetic diseases affecting kidney health. In this study, we aimed to investigate and emphasize the clinical significance of hypouricemia.
METHODS
Patients were evaluated retrospectively for persistent hypouricemia defined as serum uric acid concentrations of < 2 mg/dL on at least 3 different occasions. According to the blood and urine uric acid (UA) levels, the patients were classified as having hypouricemia due to UA underproduction vs. overexcretion. Demographic, clinical, and genetic characteristics were noted for analysis.
RESULTS
Fourteen patients (n = 14; M/F 8/6) with persistent hypouricemia were identified. Hypouricemia due to underproduction was the cause of 42.8% of these cases. All of the patients with a uric acid level of 0 mg/dL (n = 4) had hypouricemia due to underproduction. The median serum uric acid level was 0.85 (0-1.6) mg/dL. Isolated hypouricemia and hypouricemia with metabolic acidosis were equally distributed. Among the patients with hypouricemia due to underproduction, the final diagnoses were xanthine dehydrogenase deficiency (n = 5) and alkaptonuria (n = 1). In the overexcretion group, the final diagnoses were nephropathic cystinosis (n = 6), distal renal tubular acidosis (n = 1), and hereditary renal hypouricemia (n = 1). The diagnostic lag was longer for patients with isolated hypouricemia compared to other patients (p = 0.001).
CONCLUSIONS
Hypouricemia may reflect underlying genetic or metabolic diseases, early diagnosis of which could help preserve kidney function. A higher resolution version of the Graphical abstract is available as Supplementary information.
Topics: Humans; Child; Adolescent; Uric Acid; Retrospective Studies; Renal Tubular Transport, Inborn Errors; Metabolism, Inborn Errors; Acidosis, Renal Tubular; Azotemia
PubMed: 37000195
DOI: 10.1007/s00467-023-05948-4 -
Current Drug Safety 2024Phenylalanine, an essential amino acid, is the "building block" of protein. It has a tremendous role in different aspects of metabolic events. The tyrosine pathway is...
Phenylalanine, an essential amino acid, is the "building block" of protein. It has a tremendous role in different aspects of metabolic events. The tyrosine pathway is the prime one and is typically used to degrade dietary phenylalanine. Phenylalanine exceeds its limit in bodily fluids and the brain when the enzyme, phenylalanine decarboxylase, phenylalanine transaminase, phenylalanine hydroxylase (PAH) or its cofactor tetrahydrobiopterin (BH4) is deficient causes phenylketonuria, schizophrenia, attentiondeficit/ hyperactivity disorder and another neuronal effect. Tyrosine, an amino acid necessary for synthesizing the pigments in melanin, is produced by its primary metabolic pathway. Deficiency/abnormality in metabolic enzymes responsible for the catabolism pathway of Phenylalanine causes an accumulation of the active intermediate metabolite, resulting in several abnormalities, such as developmental delay, tyrosinemias, alkaptonuria, albinism, hypotension and several other undesirable conditions. Dietary restriction of the amino acid(s) can be a therapeutic approach to avoid such undesirable conditions when the level of metabolic enzyme is unpredictable. After properly identifying the enzymatic level, specific pathophysiological conditions can be managed more efficiently.
Topics: Humans; Phenylalanine; Phenylketonurias; Phenylalanine Hydroxylase; Amino Acids; Tyrosine
PubMed: 36999718
DOI: 10.2174/1574886318666230331112800 -
Sclerouveitis as Part of Multiple Autoimmune Syndrome in a Patient with Alkaptonuria: A Case Report.Ocular Immunology and Inflammation Jul 2024To present a novel association of multiple autoimmune syndrome (MAS) in a patient with sclerouveitis and alkaptonuria.
PURPOSE
To present a novel association of multiple autoimmune syndrome (MAS) in a patient with sclerouveitis and alkaptonuria.
CASE REPORT
A 68-year-old female with alkaptonuria, Hashimoto's thyroiditis, and familial autoimmunity presented with decreased VA, red eye, foreign body sensation, and ocular pain. Ophthalmological examination: OD conjunctival hyperemia, ochronosis, a reddish-violet scleral nodule, keratic precipitates, 2+ cells in the anterior chamber, 0.5+ vitreous cells, and mild vitreous haze. The patient was diagnosed with anterior uveitis and anterior nodular scleritis. Due to the associated sicca symptoms, a salivary gland biopsy was ordered, confirming Sjögren's syndrome. Then, MAS was diagnosed, and immunomodulatory medications were started; however, as she was refractory to more than two of them, it was suggested to start biological treatment.
CONCLUSION
We present a novel MAS-type 2 pattern consisting of Hashimoto's thyroiditis, sclerouveitis, and Sjögren's syndrome. Its diagnosis and management represent a challenge, so a multidisciplinary approach should be provided.
Topics: Humans; Female; Aged; Alkaptonuria; Scleritis; Sjogren's Syndrome; Hashimoto Disease; Autoimmune Diseases
PubMed: 36821816
DOI: 10.1080/09273948.2023.2179498 -
Journal of Orthopaedic Science :... Nov 2023
Topics: Humans; Atlanto-Axial Joint; Alkaptonuria; Arthritis; Zygapophyseal Joint
PubMed: 34404613
DOI: 10.1016/j.jos.2021.06.023