Recurrent symptoms of acute intermittent porphyria after biochemical normalization with givosiran-An ongoing clinical conundrum.

A 47-year-old woman with acute intermittent porphyria (AIP) has had recurring symptoms after achieving biochemical normalization of her urinary 5-aminolevulinic acid (ALA), porphobilinogen (PBG), and total porphyrins with givosiran. She has had normal liver tests, mildly decreased renal function, and sustained normal urinary ALA, PBG, and porphyrins with no rebound in her laboratory test results throughout treatment. She continues to tolerate monthly givosiran injections with no adverse effects, but she still experiences what she believes are acute porphyric attacks every 1-2 months.

Ledipasvir/Sofosbuvir Is Effective as Sole Treatment of Porphyria Cutanea Tarda with Chronic Hepatitis C.

BACKGROUND AND AIMS: Chronic hepatitis C [CHC] is a risk factor for porphyria cutanea tarda [PCT]. To assess whether ledipasvir/sofosbuvir is effective for treating both PCT and CHC, we treated patients with CHC + PCT solely with ledipasvir/sofosbuvir and followed them for at least 1 year to assess cure of CHC and remission of PCT. METHODS: Between September 2017 and May 2020, 15 of 23 screened PCT + CHC patients were eligible and enrolled. All were treated with ledipasvir/sofosbuvir at recommended doses and durations, according to their stage of liver disease. We measured plasma and urinary porphyrins at baseline and monthly for the first 12 months and at 16, 20, and 24 mos. We measured serum HCV RNA at baseline, 8-12, and 20-24 mos. Cure of HCV was defined as no detectable serum HCV RNA ≥ 12 weeks after the end of treatment (EOT). Remission of PCT was defined clinically as no new blisters or bullae and biochemically as urinary uro- plus hepta-carboxyl porphyrins ≤ 100 mcg/g creatinine. RESULTS: All 15 patients, 13 of whom were men, were infected with HCV genotype 1. 2/15 withdrew or were lost to follow-up. Of the remaining 13, 12 achieved cure of CHC; 1 had complete virological response, followed by relapse of HCV after ledipasvir/sofosbuvir but was subsequently cured by treatment with sofosbuvir/velpatasvir. Of the 12 cured of CHC, all achieved sustained clinical remission of PCT. CONCLUSIONS: Ledipasvir/sofosbuvir [and likely other direct-acting antivirals] is an effective treatment for HCV in the presence of PCT and leads to clinical remission of PCT without additional phlebotomy or low-dose hydroxychloroquine treatment. TRIAL REGISTRATION: ClinicalTrials.gov NCT03118674.

Idiosyncratic drug-induced liver injury caused by givosiran in a patient with acute intermittent porphyria.

A 39-year-old woman with biochemically and clinically active acute intermittent porphyria (AIP) developed moderately severe liver injury after receiving her second dose of givosiran. Serologic evaluation ruled out hepatitis caused by viral, autoimmune, or other metabolic etiologies. The updated Roussel Uclaf Causality Assessment Method (RUCAM) score was 8 and the Revised Electronic Causality Assessment Method (RECAM) score for givosiran was 9. Results of liver tests returned to normal after givosiran was discontinued, and she has not received any more givosiran.

Pilot study of mitochondrial bioenergetics in subjects with acute porphyrias.

BACKGROUND AND AIMS: The acute porphyrias are characterized by defects in heme synthesis, particularly in the liver. In some affected patients, there occurs a critical deficiency in a regulatory heme pool within hepatocytes that leads to up-regulation of 5-aminolevulinic acid [ALA] synthase-1, which is the first and normally rate-controlling enzyme in the pathway. In earlier work, we described defects in mitochondrial functions in cultured skin fibroblasts from patients with acute intermittent porphyria [AIP]. Others described defects in livers of murine models of AIP. Here, we explored mitochondrial energetics in peripheral blood mononuclear cells [PBMCs] and platelets in persons with AIP and hereditary coproporphyria [HCP]. Our hypotheses were that there are deficits in bioenergetic capacity in acute porphyrias and that subjects with more severe acute porphyria have more pronounced reductions in mitochondrial oxygen consumption rates [OCR]. METHODS: We studied 17 subjects with acute hepatic porphyrias, 14 with classical AIP, one with severe AIP due to homozygous deficiency of hydroxymethylbilane synthase [HMBS], 2 with HCP, and 5 non-porphyric controls. We collected peripheral blood, isolated PBMCs, which we assayed either immediately or after frozen storage [80C] for up to 14 days. Using Seahorse XF-24-3, we measured OCR in the presence of glucose + pyruvate under basal condition, and after additions of oligomycin, carbonylcyanide p-trifluoromethoxyphenylhydrazone [FCCP], and antimycin+rotenone. RESULTS: Most subjects [13/17, 76%] were female. Subjects with moderate/severe symptoms associated with acute porphyria had significantly lower basal and maximal-OCR than those with no/mild symptoms who were the same as controls. We observed significant inverse correlation between urinary porphobilinogen [PBG] excretion and OCR. The subject with homozygous AIP had a much lower-OCR than his asymptomatic parents. SUMMARY/CONCLUSIONS: Results support the hypothesis that active acute hepatic porphyria is characterized by a deficiency in mitochondrial function that is detectable in PBMCs, suggesting that limitations in electron transport and ATP production exist in such individuals.

Benefits of prophylactic heme therapy in severe acute intermittent porphyria.

Acute intermittent porphyria (AIP), an autosomal dominant inborn error of metabolism, is the most common and severe form of the acute porphyrias. Attacks of severe abdominal pain, often with hypertension, tachycardia, are cardinal features of AIP, often requiring hospital admissions. Frequent recurrent attacks of AIP, defined as >3 attacks in one year, during which at least one attack requires intravenous heme therapy, are associated with significant morbidity, lost productivity, and health care burden. We report two patients with such frequent attacks of AIP, who have been managed with prophylactic heme therapy on a weekly basis. We describe results particularly in relation to symptom control, biochemical findings, health care costs, quality of life, and utilization of resources. During 11-month duration of weekly prophylactic heme infusions, we observed a 100% decrease in acute attacks and inpatient admissions in one subject and a 75% decrease in the other. During this time, we also observed a significant decrease in the number of emergency room visits. The decrease in number of acute attacks requiring hospital admission was associated with significantly decreased health care costs and improved quality of life. Reduction of both emergency room visits and hospital admissions decreased the utilization of health care services. Outpatient weekly infusions were also noted to be associated with better reimbursements and reduced overall costs of health care for the subjects. Both our subjects also endorsed better symptom control, quality of life and better understanding of disease. Thus, prophylactic heme therapy, through a multi-disciplinary approach, decreases the incidence of acute attacks, decreases health care costs and leads to better patient satisfaction and quality of life.