An atypical case of Guillain-Barré syndrome: acute intermittent porphyria

Time is of the Essence: Using Extended Hemin Treatment for a Case of Severe Acute Intermittent Porphyria

Acute intermittent porphyria (AIP) is a disorder that affects heme synthesis, leading to accumulation of upstream precursors, and can cause an array of visceral and neurological symptoms. These can be severely debilitating and even fatal if not diagnosed and treated in a timely fashion. We outline a rare case of severe AIP masquerading as ascending polyneuropathy and how it was correctly diagnosed and treated with an extended course of hemin despite initial barriers to biochemical testing for AIP.

Hereditary Coproporphyria Mimicking Guillain-Barré Syndrome After COVID-19 Infection

Hereditary coproporphyria (HCP) is a rare disorder caused by a deficiency of an enzyme, coproporphyrinogen oxidase, in the heme synthetic pathway. This disease has a highly variable clinical presentation with acute attacks of neurologic symptoms that can last from days to months. Rarely, it and other acute porphyrias may cause ascending paralysis, which is difficult to distinguish from Guillain-Barré syndrome (GBS). Acute attacks can be triggered by factors that increase the synthesis of heme, such as hormonal changes, certain medications, dietary changes, and infections. We report a 26-year-old female with HCP who presented with acute ascending flaccid paralysis and respiratory failure after coronavirus disease 2019 (COVID-19) infection and was initially misdiagnosed and treated for GBS. She was transferred to our neurosciences intensive care unit, where the diagnosis of acute porphyria was established. Initial improvement occurred during treatment for several weeks with hemin (Panhematin®) and continued with givosiran (Givlaari®), which was recently introduced for the prevention of acute attacks. We suggest that acute porphyria should be part of the differential diagnosis when GBS is suspected. To our knowledge, this is the first report of an attack of acute hepatic porphyria (AHP) that developed after a COVID-19 infection and the first with advanced paresis to be treated with givosiran. Her response suggests that givosiran may contribute to recovery from advanced neurological manifestations of acute porphyrias.

Acute Hepatic Porphyrias: "Purple Flags"-Clinical Features That Should Prompt Specific Diagnostic Testing

BACKGROUND

Porphyrias are a group of rare diseases leading to dysregulation in heme biosynthesis and the accumulation of heme precursors, including porphyrinogens, which in their oxidized states [porphyrins] are reddish or purple. Acute hepatic porphyrias (AHP) comprise four diseases that cause acute debilitating neurovisceral attacks. Despite diagnostic advances, AHP is often undiagnosed or misdiagnosed due to a lack of disease awareness, low clinical suspicion, variable presentation, and nonspecific symptoms that mimic more common diseases. Delays in diagnosis and treatment increase the risk of serious acute and chronic complications.

METHODS

In order to assess whether symptoms alone or in combination might be utilized as important indicators or "purple flags" that, when present, should alert clinicians to suspect AHP and pursue specific diagnostic testing, we conducted a comprehensive review of the literature on AHP, including cohort studies and case reports over two epochs, from 1980 to 2006 and from 2012 to 2018.

RESULTS

We found that severe abdominal pain, with or without acute central nervous system manifestations and peripheral neuropathy, continues to be the most frequent symptom. Hyponatremia, change in urine color, and certain chronic symptoms were also identified as features that should raise suspicion of AHP. To improve diagnosis of AHP, clinicians need to take a broad perspective, including demographic data and medical history, into consideration.

CONCLUSIONS

The clinical features of AHP continue to be severe pain, especially pain in the abdomen. Other features that should raise suspicion are autonomic, peripheral, or central neuropathies, hyponatremia, and red-purple urine color.

Paediatric porphyria and human hemin: a treatment challenge in a lower middle income country

Here, we report a case of a 15-year-old girl who presented to the emergency department with symptoms of abdominal pain, nausea, vomiting and seizures. She was diagnosed with acute intermittent porphyria. Treatment was started by removing all porphogenic drugs, providing high glucose intake (oral and intravenous), which initially resulted in good clinical outcomes. However, she deteriorated again and also developed neurological manifestation (paraplegia) for which she required mechanical ventilation because of acute respiratory failure. This time she was initiated on human hemin for four consecutive days. After 2 days of therapy, her porphobilinogen levels decreased to 50% of the initial raised value. Increased lactic acid and blood urea nitrogen were the two side effects observed after the treatment, with no apparent signs of acute kidney injury. To the best of our knowledge, in paediatric population, this is the first reported case of treatment of acute intermittent porphyria with human hemin in Pakistan.

Acute intermittent porphyria after right hemi-colectomy

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Acute intermittent porphyria is rare.

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High index of suspicion is needed to diagnose acute intermittent porphyria in a patient with abdominal pain, neuro-psychiatric manifestations and hyponatremia after surgery.

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Once suspected, prompt intensive care management should include high calorie intake, symptomatic treatment of hyponatremia, use of safe medications and careful fluid-electrolyte monitoring in order to avoid serious complications and mortality.

Introduction

Acute intermittent porphyria is a rare autosomal dominant metabolic disease. It is caused by a genetic mutation that results in deficiency of porphobilinogen deaminase enzyme, the third enzyme in heme biosynthesis. Acute intermittent porphyria precipitated by surgery is very rare.

Case presentation

We present a 24 year-old woman who developed acute intermittent porphyria five days after right hemi-colectomy. Her presentation included neuro-visceral and psychiatric manifestations, and severe hyponatremia. She received critical care symptomatic management including mechanical ventilation. The diagnosis was based on a positive urine test for porphobilinogen and confirmed by the presence of a heterozygous mutation in the hydroxyrmethylbilane synthase (HMBS) gene (c.760delC p Leu254).

Discussion

Acute intermittent porphyria is the most common and life threatining type of acute porphyrias. It is more common in women and usually presents after puberty with acute abdominal pain and diverse neuro-psychiatric manifestations that can be confused with several surgical and medical diseases. Acute intermittent porphyria after surgery is most likely due to postoperative pain and low-calorie intake. Once suspected, prompt ICU management including high calorie intake are necessary to avoid serious complications and mortality before starting definitive treatment with hematin.

Conclusion

Acute intermittent porphyria should be suspected in any patient, particularly young women, who develop diverse neuro-visceral and psychiatric manifestations and hyponatremia after surgery.

Acute intermittent porphyria caused by novel mutation in HMBS gene, misdiagnosed as cholecystitis

BACKGROUND

Acute intermittent porphyria (AIP) is an autosomal dominant neurovisceral inherited disorder due to a defect in the heme biosynthesis pathway. Misdiagnosis of the porphyrias is not uncommon.

CASE REPORT

We present a case of a 26-year-old female with suspected acute cholecystitis, mental status changes, and seizures. Biochemical and molecular investigations confirmed the diagnosis of AIP by findings of elevated urinary porphobilinogen, 5-aminolevulinic acid, and total porphyrins. DNA molecular testing showed a novel heterozygous mutation (c. 760delC p.L254X) in the exon11 of the HMBS gene. To the best of our knowledge, this is the first report of a misdiagnosis of AIP presenting with acute cholecystitis.

CONCLUSION

Clinicians are alerted to consider the possibility of AIP in an adult presenting with an acute abdomen, features of cholecystitis, and neuropsychiatric manifestations.