Development of pseudobullous morphea and scleroderma-like illness during therapy with L-5-hydroxytryptophan and carbidopa

Drug-induced scleroderma-like lesion

Drug-induced scleroderma-like lesion is a condition in which administration of a drug induces skin sclerotic lesions similar to systemic sclerosis or morphea. The clinical manifestations of drug-induced scleroderma-like lesion can be divided into two types: scleroderma-like lesions and morphea-like plaques. A wide variety of drugs can cause drug-induced scleroderma-like lesion. Bleomycin, _L-tryptophan, vinyl chloride, and phytonadione (vitamin K₁) have been reported, but in recent years, cases due to chemotherapeutic agents, such as taxane-based agents, gemcitabine, and tegafur-uracil, and immune checkpoint inhibitors have increased. Drug-induced scleroderma-like lesion differs from systemic sclerosis in that it does not include Raynaud's phenomenon, nail-fold capillary abnormality, organ involvement, such as reflux esophagitis, interstitial pneumonia, renal crisis, or anti-nuclear Abs. On the other hand, there are reports of cases in which Raynaud's phenomenon, positive conversion of anti-nuclear Abs, and development of skin sclerosis from the fingers developed after initiation of the drug. Whether the skin sclerosis improves after discontinuation of the drug depends on the patient. In patients with severe skin sclerosis, functional impairment, such as flexion contracture of the fingers, may occur, and systemic therapy, such as steroids, may be necessary. When treating patients with skin sclerosis, it is important to keep in mind the possibility that the sclerotic lesion may be induced by a drug.

New-onset systemic sclerosis and scleroderma renal crisis under docetaxel

Systemic sclerosis is a rare systemic autoimmune disease characterized by microvascular impairment and fibrosis of the skin and other organs with poor outcomes. Toxic causes may be involved. We reported the case of a 59-year-old woman who developed an acute systemic sclerosis after two doses of adjuvant chemotherapy by docetaxel and cyclophosphamide for a localized hormone receptor + human epithelial receptor 2-breast cancer. Docetaxel is a major chemotherapy drug used in the treatment of breast, lung, and prostate cancers, among others. Scleroderma-like skin-induced changes (morphea) have been already described for taxanes. Here, we report for the first time a case of severe lung and kidney flare with thrombotic microangiopathy after steroids for acute interstitial lung disease probably induced by anti-RNA polymerase III + systemic sclerosis after docetaxel.

Levodopa-induced skin disorders in patients with Parkinson disease: a systematic literature review approach

The use of levodopa for treatment of Parkinson's disease is a well-established clinical practice. Data about the true incidence and severity of cutaneous complications associated with the use of levodopa are largely lacking. Aim of this review was to evaluate the quality of evidence referring to the skin disorders caused by levodopa treatment for Parkinson's disease. Thirty of 1084 studies were included; 8 randomized controlled trials and 22 case reports in a total of 2749 patients. Malignant melanoma was the most frequent oral levodopa-related skin disorder followed by allergic cutaneous reactions, alopecia, vitiligo, skin hyperpigmentation, Laugier-Hunziker syndrome, Henoch-Schönlein syndrome, pseudobullous morphea and scleroderma-like illness. Naranjo scores ranged from 2 to 8. Regarding levodopa clinical trials, the most frequent skin complication was peripheral edema, followed by malignant melanoma. Although evidence is not robust, melanoma is the most frequent and possible fatal levodopa-associated skin disorder, while other skin allergic or immunological reactions are less common and reversible. Although levodopa treatment may induce melanogenesis and promote melanomagenesis, existing evidence does not support an association between levodopa therapy and induction or progression of malignant melanoma. The suggested association with melanoma may reflect the well-documented association of Parkinson's disease with melanoma rather than the exposure to the drug. Nevertheless, until a solid conclusion can be drawn, the use of levodopa in the context of malignant melanoma should be considered with caution. Well-designed prospective studies are needed to determine the cause and effect relationship between levodopa and skin disorders.

Effects of tranilast on the urinary excretion of kynurenic and quinolinic Acid under conditions of L tryptophan loading

The pathogenesis of morphea and other cutaneous sclerosing disorders remain poorly understood. Although they are considered to be autoimmune disorders, abnormal tryptophan metabolism may be involved. Current therapy is directed to supressing the autoimmune response. Demonstration of a therapeutic response to manipulation of the kynurenine pathway would both support a role for abnormal tryptophan metabolism and offer additional targets for therapy. Tranilast is a 3-hydroxyanthranilic acid derivative known to target the kynurenine pathway. The aim of this study was to see if tranilast lowered the urinary excretion of the kynurenine metabolites kynurenic and quinolinic acid under condition of L tryptophan loading in a volunteer. Mean baseline value for kynurenic acid and quinolinic acid were 1.1 and 2.1 mmol/mol creatinine, respectively. This rose to 5.6 and 3.8 mmol/mol creatinine respectively under conditions of L tryptophan loading 2 grams daily. Adding 1 g of tranilast daily lowered the values to 2.0 and 2.9 mmol/mol creatinine, respectively. These data suggest that tranilast acts as a competitive inhibitor of either indoleamine 2, 3-dioxygenase (IDO), tryptophan 2, 3-di-oxygenase (TDO) or both. As it involved only 1 subject, the results may not be representative of the larger population and must be considered preliminary.

Safety of 5-hydroxy-L-tryptophan

5-Hydroxy-L-tryptophan (5-HTP) is the immediate precursor in the biosynthesis of 5-hydroxy-tryptamine (5-HT; serotonin) from the essential amino acid L-tryptophan (L-Trp). The use of L-Trp as a dietary supplement was discontinued in 1989 due to an outbreak of eosinophilia-myalgia syndrome (EMS) that was traced to a contaminated synthetic L-Trp from a single manufacturer. 5-HTP has since become a popular dietary supplement in lieu of the removal of L-Trp from the market. Because of its chemical and biochemical relationship to L-Trp, 5-HTP has been under vigilance by consumers, industry, academia and government for its safety. However, no definitive cases of toxicity have emerged despite the worldwide usage of 5-HTP for last 20 years, with the possible exception of one unresolved case of a Canadian woman. Extensive analyses of several sources of 5-HTP have shown no toxic contaminants similar to those associated with L-Trp, nor the presence of any other significant impurities. A minor chromatographic peak (peak X) reported in some 5-HTP samples lacks credibility due to chromatographic artifacts and infinitesimal concentrations, and has raised undue speculations concerning its chemistry and toxicity.

Autoimmunity and selected environmental factors of disease induction

Autoimmune diseases may be induced by physical and/or chemical environmental factors. A review of the available literature on mercuric chloride, iodine, silicone, anilides, L-tryptophan, vinyl chloride, and canavanine suggests three general mechanisms by which they may induce disease. First, oxidative damage probably is a frequent process involved in disease induction and pathogenesis. Second, certain compounds also may generate antigen-specific immune responses that could then cross-react with self-tissues. Other xenobiotics might bind to self-tissues and increase self-tissue immunogenicity. Third, physical and chemical agents may also modulate the immune system. Finally, in response to controversies surrounding the influence of human activities on global climate changes, the immunosuppressive effects of ozone and ultraviolet radiation are discussed.

Tryptophan metabolism via the kynurenine pathway in patients with the eosinophilia-myalgia syndrome

OBJECTIVE

To investigate the metabolism of L-tryptophan (LT) via the kynurenine pathway in patients with the eosinophilia-myalgia syndrome (EMS).

METHODS

Measurement of LT, L-kynurenine, and quinolinic acid in plasma and cerebrospinal fluid (CSF) from subjects with EMS, from asymptomatic users of LT, and from normal subjects.

RESULTS

Plasma LT concentrations were lower in untreated EMS patients (n = 5) than in corticosteroid-treated EMS patients (n = 5; P less than 0.05) and in asymptomatic users of LT (n = 5; P less than 0.05). Untreated EMS patients, who had discontinued LT weeks to months prior to study, had significantly higher plasma levels of L-kynurenine and quinolinic acid than did corticosteroid-treated EMS patients (P less than 0.05), normal subjects (P less than 0.02), and asymptomatic users of LT (P less than 0.05). EMS patients also had significantly elevated levels of L-kynurenine (P less than 0.05) and quinolinic acid (P less than 0.001) in CSF compared with normal subjects. After a 1-gm oral dose of LT, untreated EMS patients (n = 4) showed lower peak levels of LT and accentuated synthesis of L-kynurenine and quinolinic acid, compared with these values in corticosteroid-treated EMS patients (n = 2), who responded like normal subjects (n = 5).

CONCLUSION

These data demonstrate that during the active phase of EMS, LT metabolism via the kynurenine pathway was accentuated, probably secondary to induction of the enzyme indoleamine-2,3-dioxygenase. Ingestion of large amounts of LT (median daily dose 1.5 gm) resulted in high concentrations of kynurenine-pathway metabolites in blood and extrahepatic tissues, which was accentuated in EMS patients and which may have played a significant role in the pathogenesis of the disease.