Porphyrias are inherited defects in the biosynthesis of haem. Attacks in acute intermittent porphyria are characterised by abdominal pain, neurological disturbances, and psychiatric disorders; in severe cases, they may lead to respiratory paralysis and coma. The disease carries a 5-year mortality rate of 20–25%, mostly in young adults and especially in females in their second and third decade of life. The condition is less frequent in males (mostly taking place during the third–fourth decade of life), is rare in children, and even rarer after the fifth decade of life.
Patients experienced renal colic-like pain, with pallor, nausea, vomiting, fever, acute urinary retention, and hyperchromic urine emission (urine may turn dark red). There are multiple inducing factors: drugs, alcohol, stress, fasting, menstruation, and infections. The incidence of acute porphyria is rated 0.54/100,000 (according to Orphanet, November 2016).1,2 Renal involvement in acute porphyrias is represented by hyponatraemia, urinary retention, tubulo-interstitial nephropathy, hypertension, and chronic kidney disease (CKD).
A 68-year-old woman, undergoing haemodialysis three-times a week since January 2011 (32 months) for CKD due to undiagnosed nephropathy, has been diagnosed with acute intermittent porphyria through biomolecular analysis performed as part of a family screening. In September 2013, she was admitted to the Nephrology Unit for abdominal pain, constipation, and uncontrolled hypertension. Since she had no diuresis, plasma porphyrins were measured, peaking at 619 nm. The patient reported depression and progressive muscle weakness in her legs and then, the following day, in her arms, defining a medical case of flaccid tetraparesis. Supposing she had polyradiculoneuritis, a lumbar puncture was made and was negative. Two days later, she was given haemin (Normosang®, Orphan Europe, Puteaux, France), at a dose of 3 mg/kg/24 hours for 4 straight days, and then twice a week for the following 2 months, during which time she was moved to the Rehabilitation Medicine Unit, where she started a rehabilitation plan.
Functional evaluation was assessed by the Barthel scale (BS) (values from 0–100), while muscular strength of involved paretic muscles was assessed by the Medical Research Council (MRC) scale (values from 0–60; 0–5 for muscle bundle for three muscle groups for the four limbs), respectively, at admission, 2 weeks, 4 weeks, and at discharge. The patient underwent rehabilitation including electrical stimulation and occupational therapy.
At admission, BS score was 25, which indicated severe disability. Likewise, neurological imaging showed severe impairment of strength characterised by tetraplegia. MRC score was 0 in both upper and lower limbs.
After haemin administration and rehabilitation treatment, muscular deficit progressively improved and MRC scores were 24, 36, and 50, at 2 weeks, 4 weeks, and at discharge, respectively. Likewise, good functional outcome was also observed, with BS scores of 45, 65, and 90 at 2 weeks, 4 weeks, and at discharge, respectively. After 40 months, the patient had no more abdominal pain or constipation. Blood pressure, motor skills, and muscle strength are back to normal values, after mild weakness. Currently, the patient is taking haemin every 4 months and, given her good state of health, it is likely she will be given haemin every 6 months until total discontinuation. The patient will keep on following a normocaloric, hyperglucidic diet with maltodestrins.