Mortality in patients with acute intermittent porphyria requiring hospitalization: a United States case series

Long-term complications in acute porphyria

New treatment options and low attack-related mortality have changed the life expectancy of patients with acute porphyria (AP) to that of the general population. Clinicians should therefore be aware of the long-term complications of AP, which typically include chronic neuropathy and encephalopathy, high blood pressure and porphyria-associated kidney disease. Patients have an increased risk of primary liver cancer (PLC), but no increased risk of non-hepatic cancers. Chronic pain occurs in patients with recurrent attacks, combined with chronic fatigue and nausea, leading to poor quality of life. Patients with sporadic attacks may also have chronic symptoms, which should be distinguished from mild recurrent attacks and treated appropriately. Sequels of acute polyneuropathy after an attack should be distinguished from ongoing chronic polyneuropathy, as the management is different. Overestimation of chronic neuropathy or encephalopathy caused by AP should be avoided, and other causes should be treated accordingly. Prevention of recurrent attacks is the best strategy for managing chronic comorbidities and should be actively accomplished. Hormonal interventions in female patients, or in severe cases, prophylactic givosiran or haematin, may be helpful before liver transplantation to prevent recurrent attacks. Regular monitoring can be personalised according to the patient's age, comorbidities and AP activity. Blood pressure, renal function and cardiovascular risk factors should be monitored annually in patients with previous symptoms. Appropriate medication and lifestyle management, including nutrition and hydration, are necessary to prevent complications. As PLC is common, especially in patients with acute intermittent porphyria, bi-annual surveillance after the age of 50 is important.

Acute hepatic porphyrias-A guide for hepatologists

The acute hepatic porphyrias (AHPs) are a group of rare, inherited disorders of the heme biosynthesis pathway, usually manifesting with attacks of acute abdominal pain and other neurovisceral symptoms, with or without cutaneous manifestations. AHPs are characterized by the accumulation of porphyrin precursors, porphobilinogen, and/or aminolevulinic acid, in the blood. The diagnosis is often missed or delayed due to both inadequate testing and the improper use of available laboratory tests. In this review, we describe the various clinical presentations of the 4 AHPs, elucidate the approach to diagnosis, and provide recommendations for immediate and long-term management. We also describe the different complications that can occur with long-standing AHP, including the development of HCC. The AHPs are very treatable conditions, with excellent outcomes if diagnosed and treated early. A high index of suspicion for the presence of these disorders, along with accurate testing and timely treatment, will help reduce the burden of disease and prevent irreversible complications in patients with AHP.

Portuguese Consensus on Acute Porphyrias: Diagnosis, Treatment, Monitoring and Patient Referral

Acute porphyrias are a group of rare genetic metabolic disorders, caused by a defect in one of the enzymes involved in the heme biosynthesis, which results in an abnormally high accumulation of toxic intermediates. Acute porphyrias are characterized by potentially life-threatening attacks and, for some patients, by chronic manifestations that negatively impact daily functioning and quality of life. Clinical manifestations include a nonspecific set of gastrointestinal, neuropsychiatric, and/or cutaneous symptoms. Effective diagnostic methods are widely available, but due to their clinical heterogeneity and non-specificity, many years often elapse from symptom onset to diagnosis of acute porphyrias, delaying the treatment and increasing morbidity. Therefore, increased awareness of acute porphyrias among healthcare professionals is paramount to reducing disease burden. Treatment of acute porphyrias is centered on eliminating the potential precipitants, symptomatic treatment, and suppressing the hepatic heme pathway, through the administration of hemin or givosiran. Moreover, properly monitoring patients with acute porphyrias and their relatives is fundamental to preventing acute attacks, hospitalization, and long-term complications. Considering this, a multidisciplinary panel elaborated a consensus paper, aiming to provide guidance for an efficient and timely diagnosis of acute porphyrias, and evidence-based recommendations for treating and monitoring patients and their families in Portugal. To this end, all authors exhaustively reviewed and discussed the current scientific evidence on acute porphyrias available in the literature, between November 2022 and May 2023.

Rare causes of abdominal pain: a primer for the admitting general surgeon

The broad uptake of the acute surgical unit (ASU) model of surgical care in Australia has resulted in general surgeons becoming increasingly involved in the management of patients with acute abdominal pain (AAP), some of whom will be labelled as having non-specific abdominal pain (NSAP) (Kinnear N, Jolly S, Herath M, et al. The acute surgical unit: An updated systematic review and meta-analysis. review. Int. J. Surg. 2021;94:106109; Lehane CW, Jootun RN, Bennett M, Wong S, Truskett P. Does an acute care surgical model improve the management and outcome of acute cholecystitis? ANZ J. Surg. 2010;80:438-42). NSAP patients lack a clear diagnosis of surgical pathology based on standard clinical, laboratory and imaging work-up, although they may require ASU admission for pain control and assessment. This article provides a review of uncommon conditions, presenting as AAP, that could possibly be mis-labelled as NSAP, with a focus on aspects of the presentation that may aid diagnosis and management including specific demographic features, clinical findings, key investigations and initial treatment priorities for ASU clinicians. Ultimately, most of the conditions discussed will not require surgical intervention, however, they require a diagnosis to be made and initial treatment planning before on-referral to the appropriate specialty. For the on-call general surgeon, some knowledge of these conditions and an index of suspicion are invaluable for the prompt diagnosis and efficient management of these patients.

Mortality in Pedigrees with Acute Intermittent Porphyria

High mortality rates have been reported in historical cohorts of acute intermittent porphyria (AIP) patients. The mortality associated with (hydroxymethylbilane synthase) HMBS variant heterozygosity is unknown. This study estimates all-cause mortality in pedigrees with HMBS gene variants that cause AIP. We collected data on the lifespan of individuals in Dutch AIP pedigrees and performed analyses using the family tree mortality ratio method. This gave us standardized mortality ratios for these pedigrees compared to the Dutch general population as a primary outcome. Between 1810 and 2017, the overall mortality in these pedigrees was identical to that of the general Dutch population: (SMR 1.01, p = 0.441). However, compared with the general population the SMR was significantly higher in women aged 45−64 years (SMR 1.99, p = 0.00003), which was based on excess mortality between 1915 and 1964 (SMR 1.94, p < 0.00002). In men aged 70−74 years, the SMR was 1.55 (p = 0.0021), based on excess mortality that occurred between 1925 and 1964 (SMR 1.92, p = 0000000003). Overall, mortality from HMBS variant heterozygosity was not increased compared with the general population. Severe excess mortality occurred in young women and old men between 1915 and 1964. Heterozygotes reached a normal lifespan during the past half-century, in parallel with disease awareness and the prevention of new attacks through family counselling.

Disease burden in patients with acute hepatic porphyria: experience from the phase 3 ENVISION study

Background

Acute hepatic porphyria (AHP) is a family of four rare genetic diseases, each involving deficiency in a hepatic heme biosynthetic enzyme. Resultant overproduction of the neurotoxic intermediates δ-aminolevulinic acid (ALA) and porphobilinogen (PBG) leads to disabling acute neurovisceral attacks and progressive neuropathy. We evaluated the AHP disease burden in patients aged ≥ 12 years in a post hoc analysis of the Phase 3, randomized, double-blind, placebo-controlled ENVISION trial of givosiran (NCT03338816), an RNA interference (RNAi) therapeutic that targets the enzyme ALAS1 to decrease ALA and PBG production. We analyzed baseline AHP severity via chronic symptoms between attacks, comorbidities, concomitant medications, hemin-associated complications, and quality of life (QOL) and evaluated givosiran (2.5 mg/kg monthly) in patients with and without prior hemin prophylaxis on number and severity of attacks and pain scores during and between attacks.

Results

Participants (placebo, n = 46; givosiran, n = 48) included patients with low and high annualized attack rates (AARs; range 0–46). At baseline, patients reported chronic symptoms (52%), including nausea, fatigue, and pain; comorbidities, including neuropathy (38%) and psychiatric disorders (47%); concomitant medications, including chronic opioids (29%); hemin-associated complications (eg, iron overload); and poor QOL (low SF-12 and EuroQol visual analog scale scores). A linear relationship between time since diagnosis and AAR with placebo suggested worsening of disease over time without effective treatment. Givosiran reduced the number and severity of attacks, days with worst pain scores above baseline, and opioid use versus placebo.

Conclusions

Patients with AHP, regardless of annualized attack rates, have considerable disease burden that may partly be alleviated with givosiran.

Long-term follow-up of acute porphyria in female patients: Update of clinical outcome and life expectancy

Background

Acute hepatic porphyria includes four inherited disorders caused by partial deficiencies of enzymes related to the heme biosynthesis. Clinical manifestations include acute attacks, occurring mainly among female patients. This study describes the diversity of acute symptoms, changes in triggering factors and life expectancy among female patients during the past five decades.

Methods

107 Finnish female patients were enrolled into a retrospective, longitudinal study during 2015. Clinical, biochemical and genetic data was obtained from the medical reports, registry data and a questionnaire designed for the study. Causes of death were studied in additional 32 female patients.

Results

Of the 43 patients with hospitalization, 33% had non-complicated, 35% prolonged and 28% severe attacks with no correlation with the disease-causing mutation. Of the deceased patients, 31% died of an acute attack during 1957–1979. Thereafter the incidence and severity of acute attacks have decreased substantially. 55% of the subjects reported acute symptoms (dysautonomia and mental symptoms) without hospitalization, 29% had porphyria symptoms >10 times, and 23% within the last year. Despite 22% of the female patients had died of primary liver cancer, the life expectancy increased more than 10 years during the follow-up, and did not differ from the normal population at present.

Conclusions

The incidence of acute attacks requiring hospitalization has decreased, but more than half of the female patients reported acute symptoms affecting their well-being. Symptoms are currently triggered by hormonal changes and weight loss emphasizing the importance of early recognition and active management to avoid disease exacerbation. Death due to primary liver cancer is common and should be screened regularly.

Expert consensus statement on acute hepatic porphyria in Belgium

Acute hepatic porphyrias (AHP) are a group of four different rare to ultra-rare, severely debilitating, and sometimes fatal diseases that significantly impact patients' lives: 5-aminolevulinic acid (ALA) dehydratase deficiency porphyria (ADP), acute intermittent porphyria (AIP), hereditary coproporphyria (HCP), and variegate porphyria (VP). Based on literature estimates, a conservative estimate of the number of AHP patients in Belgium requiring treatment, defined as patients experiencing recurrent attacks and/or chronic debilitating symptoms, is likely limited to 11-34 patients. These patients face a considerable unmet need, as there is currently no pharmaceutical treatment available that effectively prevents attacks and has an impact on other chronic symptoms of the disease.A panel consisting of the two European Porphyria Network¹ (EPNet) centers in Belgium (Center for inborn errors of metabolism of UZ Leuven and the 'Centre Belge des Porphyries' of Erasme Hospital and LHUB-ULB) participated in an advisory board on 24 January 2020. Representatives of the sponsoring pharmaceutical company, Alnylam Pharmaceuticals, organized and attended the meeting. The objective of the meeting was to obtain expert input on the state-of-the-art clinical practice of AHP in Belgium. Following this meeting, this expert consensus statement was drafted, in collaboration with and coordinated by the EPNet centers in Belgium. This statement provides an overview of the state-of-the art in AHP, by means of a concise overview of AHP pathophysiology, clinical manifestations, and burden of disease, (Belgian) epidemiology, treatments, and proposed organization of care.

The acute hepatic porphyrias

The acute hepatic porphyrias (AHP) are a group of four inherited diseases of heme biosynthesis. They present with similar severe, episodic, acute neurovisceral symptoms due to abnormally elevated levels of porphyrin precursors delta-aminolevulinic acid (ALA). Recently genetic screening indicates that the prevalence of mutation carrier state is more common than previously thought, occurring in 1 in 1,500, though the clinical penetrance of symptomatic AHP is low at ~1%. Symptomatic attacks occur primarily in females during their reproductive years. In an acute porphyria attack, the primary symptom is abdominal pain, due to intestinal dysmotility from autonomic nerve injury. Other manifestations include seizures, weakness and mood changes, point to injury involving peripheral and central nervous system. Due to the non-specific nature of the symptoms and signs in AHP, the diagnosis is often delayed by many years. The diagnosis of AHP depends on biochemical evidence of elevated ALA and PBG levels in urine during symptomatic attacks. Genetic testing is used for confirmation of the gene involved and the exact mutation. Treatment involves administration of heme, which downregulates production of ALA. Long-term management centers on educating genetic carriers on avoiding triggers that increase the risk of acute attacks and screening family members.

Penetrance and predictive value of genetic screening in acute porphyria

OBJECTIVE

Penetrance, predictive value and female patients' perspectives on genetic testing were evaluated among Finnish patients with acute porphyria. We conducted a retrospective study to evaluate prognosis among at-risk female family members depending on the primary method of diagnosis.

METHODS

The penetrance was calculated among 23 genetically heterogeneous families selected from the Finnish porphyria registry (n = 515, AIP 333; VP 182). We included kindreds with ≥9 patients in a family (range 9-23 patients, total 216 AIP; 129 VP). In 2015, the registry included 164 living female subjects between 14 and 85 years of age. A questionnaire was sent to 143 women, of whom 107 (75%, AIP 67; VP 40) replied. Female at-risk relatives (AIP 54; VP 30) were divided into two groups based on the primary method of diagnosis: mutation analysis (Group A, n = 40) or biochemical analysis (Group B, n = 44).

RESULTS

Mean penetrance for all acute symptoms was 35% among AIP and 40% among VP families. In both study groups, the penetrance was higher among female (AIP 50%; VP 44%) than male patients (AIP 17%; VP 33%). Penetrance for hospitalized attacks was 30% among AIP families (range 10-80%, for women 41%) and 25% in VP (range 0-50%, for women 27%) demonstrating wide variations among families even with the similar genotype. Acute porphyria was diagnosed at the median age of 26 years (range 0-76 years) among female patients, commonly after the onset of acute symptoms. Diagnostic delay was an average of 7.4 years (range 1-30 years). Acute symptoms occurred at the median age of 24 years (range 10-57 years) and the first hospitalization at the median age of 26.5 years (range 15-57 years). At the onset of symptoms, 38% of the women were ≤ 20 years of age. According to the life table analysis, acute attacks occurred mainly during the following five years after the diagnosis and the attack risk diminished after 35 years of age. The annual risk for hospitalization due to an acute attack during fertile years was lower in Group A than Group B (0.002 vs. 0.010, p = .018), but the risk of all subsequent acute symptoms did not diminish (Group A 0.017 vs. Group B 0.019, p = .640). The cumulative risk of acute symptoms among asymptomatic patients at the time of diagnosis was 26.7% for Group A and 58.3% for Group B. The cumulative risk of the first subsequent attack requiring hospitalization after the diagnosis among all at-risk relatives was similarly less frequent in Group A than in Group B (OR 0.180; 95% CI 0.041-0.789, p = .041). If attacks were followed among symptomatic patients only, attack-free years were more frequent in Group A than in Group B. Patients preferred genetic screening before puberty to minimize the risk of acute symptoms and genetic discrimination was rare. 44% of the patients reported social, psychological or physical impairment due to acute hepatic porphyria, emphasizing the importance of supporting patients' emotional and resilience capacity.

CONCLUSIONS

Among female at-risk relatives the annual risk for hospitalization due to an acute attack is <1% and for acute symptoms <2% during the fertile years. Genetic testing of relatives diminishes the risk of acute attacks. Diagnosis before symptom onset is key for subjects to remain asymptomatic during follow-up, and genetic screening should be done earlier than currently.

Sick leave, disability, and mortality in acute hepatic porphyria: a nationwide cohort study

Background

Acute hepatic porphyria (AHP) consists of three rare metabolic disorders. We investigated the risk of long-term sick leave, disability pension, and premature death in individuals with AHP compared to the general population.

Methods

In a nationwide cohort study from 1992 to 2017, records of 333 persons (total person-years = 6728) with a confirmed AHP diagnosis were linked to several national compulsory registries (reference population = 5,819,937). We conducted survival analyses to assess additional risk.

Results

Persons with AHP had higher risks of accessing long-term sick leave (adjusted hazard ratio (aHR): 1.5, 95% confidence interval (CI): 1.3, 1.7) and disability pension (aHR: 1.9, CI: 1.5, 2.4). The risk was highest in persons who had been hospitalised for acute attacks, while no additional risk was observed in asymptomatic AHP gene mutation carriers. The median age when accessing disability pension was 45 years, 21 years younger than the general population. AHP was associated with increased risk of mortality due to hepatocellular carcinoma (adjusted mortality rate ratio (aMRR): 84.4, CI: 37.8, 188.2), but no overall increased risk of premature death was observed.

Conclusions

Persons with symptomatic AHP were at increased risk of accessing long-term sick leave and disability pension but not of premature death.

Acute hepatic porphyrias: Current diagnosis & management

Each of the four acute hepatic porphyrias is due to mutation of an enzyme in the heme biosynthetic pathway. The accumulation of pathway intermediates that occur most notably when these diseases are active is the basis for screening and establishing a biochemical diagnosis of these rare disorders. Measurement of enzyme activities and especially DNA testing also are important for diagnosis. Suspicion of the diagnosis and specific testing, particularly measurement of urinary porphobilinogen, are often delayed because the symptoms are nonspecific, even when severe. Urinary porphyrins are also measured, but their elevation is much less specific. If porphobilinogen is elevated, second line testing will establish the type of acute porphyria. DNA testing identifies the familial mutation and enables screening of family members. Management includes removal of triggering factors whenever possible. Intravenous hemin is the most effective treatment for acute attacks. Carbohydrate loading is sometimes used for mild attacks. Cyclic attacks, if frequent, can be prevented by a GnRH analogue. Frequent noncyclic attacks are sometime preventable by scheduled (e.g. weekly) hemin infusions. Long term complications may include chronic pain, renal impairment and liver cancer. Other treatments, including RNA interference, are under development.

Porphyria Attack Manifesting as Delayed Emergence and Precipitated by Prolonged Cardiopulmonary Bypass: A Case Report of 2 Novel Observations

Acute porphyria is a group of rare disorders in the biosynthesis pathway of heme that can result in severe neurovisceral attacks leading to morbidity and mortality. Perioperative complications have been largely prevented due to avoidance of precipitants and early treatment of symptoms. However, these measures may not always be successful, because not all physiological stressors can be evaded. This case illustrates a porphyria attack precipitated by prolonged cardiopulmonary bypass that manifested as postoperative delayed emergence, failure to wean from mechanical ventilation, autonomic insufficiency requiring significant vasoactive agents, and, ultimately, failure to thrive. The patient passed after withdrawal of care.

Patient Perspective on Acute Intermittent Porphyria with Frequent Attacks: A Disease with Intermittent and Chronic Manifestations

Objective

Acute intermittent porphyria is a rare metabolic disorder that affects heme synthesis. Patients with acute intermittent porphyria may experience acute debilitating neurovisceral attacks that require frequent hospitalizations and negatively impact quality of life. Although clinical aspects of acute intermittent porphyria attacks have been documented, the experience of patients is not well known, particularly for those more severely affected patients who experience frequent attacks. The aim of the present study was to qualitatively characterize the experience of patients with acute intermittent porphyria who have frequent attacks, as well as the impact of the disease on daily living.

Methods

Patients with acute intermittent porphyria who experience frequent attacks were recruited and took part in 2-h qualitative one-on-one interviews with a semi-structured guide. Interviews were anonymized, transcribed, and coded. The inductive coding approach targeted textual data related to acute intermittent porphyria attack symptoms, chronic symptoms, and the impact of the disease. Saturation analysis was conducted to assess whether the research elicited an adequate account of patients’ experiences.

Results

In total, 19 patients with acute intermittent porphyria were interviewed (mean age 40 years; 79% female). Eighteen patients (95%) experienced both attack and chronic symptoms. Patients described attacks as the onset of unmanageable symptoms that generally lasted 3–5 days requiring hospitalization and/or treatment. Pain, nausea, and vomiting were considered key attack symptoms; pain, nausea, fatigue, and aspects of neuropathy (e.g., tingling and numbness) were considered key chronic symptoms.

Conclusions

In this study population of acute intermittent porphyria with frequent attacks, most patients had symptoms during and between attacks. In these patients, acute intermittent porphyria appears to have acute exacerbations as well as chronic day-to-day manifestations, and is not just intermittent as its name implies. As a result, patients reported limitations in their ability to function across multiple domains of their lives on a regular basis and not just during acute attacks.

Electronic supplementary material

The online version of this article (10.1007/s40271-018-0319-3) contains supplementary material, which is available to authorized users.

Acute Hepatic Porphyrias: Review and Recent Progress

The acute hepatic porphyrias (AHPs) are a group of four inherited diseases of heme biosynthesis that present with episodic, acute neurovisceral symptoms. The four types are 5-aminolevulinic acid (ALA) dehydratase deficiency porphyria, acute intermittent porphyria, hereditary coproporphyria, and variegate porphyria. Their diagnoses are often missed or delayed because the clinical symptoms mimic other more common disorders. Recent results indicate that acute intermittent porphyria, the most severe of the more common types of AHP, is more prevalent than previously thought, occurring in about 1 in 1600 Caucasians, but with low clinical penetrance (approximately 2%-3%). Here we provide an updated review of relevant literature and discuss recent and emerging advances in treatment of these disorders. Symptomatic attacks occur primarily in females between 14 and 45 years of age. AHP is diagnosed by finding significantly elevated levels of porphyrin precursors ALA and porphobilinogen in urine. Acute attacks should be treated promptly with intravenous heme therapy to avoid the development of potentially irreversible neurologic sequelae. All patients should be counseled about avoiding potential triggers for acute attacks and monitored regularly for the development of long-term complications. Their first-degree relatives should undergo targeted gene testing. Patients who suffer recurrent acute attacks can be particularly challenging to manage. Approximately 20% of patients with recurrent symptoms develop chronic and ongoing pain and other symptoms. We discuss newer treatment options in development, including small interfering RNA, to down-regulate ALA synthase-1 and/or wild-type messenger RNA of defective genes delivered selectively to hepatocytes for these patients. We expect that the newer treatments will diminish and perhaps obviate the need for liver transplantation as treatment of these inborn metabolic disorders.

Acute Hepatic Porphyrias in Colombia: An Analysis of 101 Patients

BACKGROUND

There is minimal information available about acute hepatic porphyrias (AHPs) in developing countries. The aim of this study was to describe the demographics, clinical features, and mortality of AHPs in Colombia.

PATIENTS AND METHODS

121 patients with presumed diagnosis of AHPs were reported in Colombia between 1944 and 2018. A pooled analysis of 53 patients with confirmed diagnosis was performed to evaluate the demographics, clinical features, and mortality of AHPs in the country. Selected variables were compared by periods (1952-2000 and 2001-2018).

RESULTS

Most attacks occurred in women (66%), with a women-to-man ratio of 39/14. 96% of the patients were diagnosed with AHPs between 15 and 40 years of age. Precipitants were identified in 71% of attacks and more than one precipitant in 41% of them. Drugs (85%) and infections (44%) were the most common precipitants. 11% of women had premenstrual attacks. Abdominal pain was the most common symptom (96%). Cortical blindness, posterior reversible encephalopathy syndrome, and rhabdomyolysis were described. 70% of attacks were confirmed by qualitative test only. 67% of attacks were treated with intravenous heme. The use of heme increased from 4 to 85% in the last two decades. Mortality decreased about twofold in relation to the increase in the use of heme. Severe motor neuropathy was associated with increased mortality. Gonadorelin analogues, heme prophylaxis, and orthotopic liver transplantation have been used to prevent recurrent attacks.

CONCLUSIONS

Diagnosis and treatment of AHPs in Colombia have improved in recent decades. However, there are still important shortcomings to address.

An update of clinical management of acute intermittent porphyria

Acute intermittent porphyria (AIP) is due to a deficiency of the third enzyme, the hydroxymethylbilane synthase, in heme biosynthesis. It manifests with occasional neuropsychiatric crises associated with overproduction of porphyrin precursors, aminolevulinic acid and porphobilinogen. The clinical criteria of an acute attack include the paroxysmal nature and various combinations of symptoms, such as abdominal pain, autonomic dysfunction, hyponatremia, muscle weakness, or mental symptoms, in the absence of other obvious causes. Intensive abdominal pain without peritoneal signs, acute peripheral neuropathy, and encephalopathy usually with seizures or psychosis are the key symptoms indicating possible acute porphyria. More than fivefold elevation of urinary porphobilinogen excretion together with typical symptoms of an acute attack is sufficient to start a treatment. Currently, the prognosis of the patients with AIP is good, but physicians should be aware of a potentially fatal outcome of the disease. Mutation screening and identification of type of acute porphyria can be done at the quiescent phase of the disease. The management of patients with AIP include following strategies: A, during an acute attack: 1) treatment with heme preparations, if an acute attack is severe or moderate; 2) symptomatic treatment of autonomic dysfunctions, polyneuropathy and encephalopathy; 3) exclusion of precipitating factors; and 4) adequate nutrition and fluid therapy. B, during remission: 1) exclusion of precipitating factors (education of patients and family doctors), 2) information about on-line drug lists, and 3) mutation screening for family members and education about precipitating factors in mutation-positive family members. C, management of patients with recurrent attacks: 1) evaluation of the lifestyle, 2) evaluation of hormonal therapy in women, 3) prophylactic heme therapy, and 4) liver transplantation in patients with severe recurrent attacks. D, follow-up of the AIP patients for long-term complications: chronic hypertension, chronic kidney insufficiency, chronic pain syndrome, and hepatocellular carcinoma.

Acute Hepatic Porphyria

The porphyrias comprise a set of diseases, each representing an individual defect in one of the eight enzymes mediating the pathway of heme synthesis. The diseases are genetically distinct but have in common the overproduction of heme precursors. In the case of the acute (neurologic) porphyrias, the cause of symptoms appears to be overproduction of a neurotoxic precursor. For the cutaneous porphyrias, it is photosensitizing porphyrins. Some types have both acute and cutaneous manifestations. The clinical presentation of acute porphyria consists of abdominal pain, nausea, and occasionally seizures. Only a small minority of those who carry a mutation for acute porphyria have pain attacks. The triggers for an acute attack encompass certain medications and severely decreased caloric intake. The propensity of females to acute attacks has been linked to internal changes in ovarian physiology. Symptoms are accompanied by large increases in delta-aminolevulinic acid and porphobilinogen in plasma and urine. Treatment of an acute attack centers initially on pain relief and elimination of inducing factors such as medications; glucose is administered to reverse the fasting state. The only specific treatment is administration of intravenous hemin. An important goal of treatment is preventing progression of the symptoms to a neurological crisis. Patients who progress despite hemin administration have undergone liver transplantation with complete resolution of symptoms. A current issue is the unavailability of a rapid test for urine porphobilinogen in the urgent-care setting.

Acute porphyrias in the USA: features of 108 subjects from porphyrias consortium

BACKGROUND

Recent descriptions of the clinical and laboratory features of subjects with acute porphyrias in the US are lacking. Our aim was to describe clinical, biochemical, and genetic features of 108 subjects.

METHODS

Between September 2010 and December 2012, 108 subjects with acute porphyrias (90 acute intermittent porphyrias, 9 hereditary coproporphyrias, 9 variegate porphyrias) were enrolled into an observational study. Genetic testing was performed at a central genetic testing laboratory and clinical information entered into a central database. Selected features were compared with data for adults in the US.

RESULTS

Most subjects (88/108, 81%) were female, with self-reported onset of symptoms in the second through fourth decades of life. The most common symptom was abdominal pain. Appendectomies and cholecystectomies were common before a diagnosis of porphyria. The diagnosis was delayed by a mean of 15 years. Anxiety and depression were common, and 18% complained of chronic symptoms, especially neuropathic and other pains. The incidences of systemic arterial hypertension, chronic kidney disease, seizure disorders, and psychiatric conditions were markedly increased. Mutations of the known causative genes were found in 102/105 of those tested, with novel mutations being found in 37, including in 7/8 subjects with hereditary coproporphyria. Therapy with intravenous hematin was the most effective therapy both for treatment of acute attacks and for prevention of recurrent attacks.

CONCLUSIONS

Acute porphyrias often remain undiagnosed for more than a decade after first symptoms develop. Intravenous hematin is the treatment of choice, both for treatment of acute attacks and for prevention of recurrent attacks.

A challenging diagnosis for potential fatal diseases: recommendations for diagnosing acute porphyrias

Acute porphyrias are a heterogeneous group of metabolic disorders resulting from a variable catalytic defect of four enzymes out of the eight involved in the haem biosynthesis pathway; they are rare and mostly inherited diseases, but in some circumstances, the metabolic disturbance may be acquired. Many different environmental factors or pathological conditions (such as drugs, calorie restriction, hormones, infections, or alcohol abuse) often play a key role in triggering the clinical exacerbation (acute porphyric attack) of these diseases that may often mimic many other more common acute medical and neuropsychiatric conditions and whose delayed diagnosis and treatment may be fatal. In order to obtain an accurate diagnosis of acute porphyria, the knowledge and the use of appropriate diagnostic tools are mandatory, even in order to provide as soon as possible the more effective treatment and to prevent the use of potentially unsafe drugs, which can severely precipitate these diseases, especially in the presence of life-threatening symptoms. In this paper, we provide some recommendations for the diagnostic steps of acute porphyrias by reviewing literature and referring to clinical experience of the board members of the Gruppo Italiano Porfiria (GrIP).

Review of hepatocellular cancer, hypertension and renal impairment as late complications of acute porphyria and recommendations for patient follow-up

This review critically appraises the data emerging from small retrospective and prospective cohort studies suggesting that patients with the autosomal dominant acute porphyrias may be at increased risk of hepatocellular cancer (HCC), hypertension (HT) and renal impairment. The most striking finding is a marked excess risk of HCC in Swedish patients with acute intermittent porphyria (AIP). As Sweden has a relatively high prevalence of AIP due to a founder effect, it is uncertain to what extent the finding is generalisable to other populations or other acute porphyrias and whether early intervention through screening can improve outcomes. As yet there is no evidence for the cost-effectiveness of systematic surveillance for HCC in acute porphyria outside Sweden. Data from several populations also suggest a high prevalence of chronic sustained HT and renal impairment in AIP, but it is uncertain if this represents a true excess risk, in particular for asymptomatic patients. As these long-term complications are important and potentially treatable, a pragmatic recommendation is that symptomatic patients with acute porphyria should be offered specialist long-term follow-up and, for those aged >50 years, annual liver ultrasound may be considered following discussion of the likely risks and benefits. Opportunistic cardiovascular risk assessment can readily be incorporated into a structured annual review so that appropriate drugs safe for use in acute porphyria are prescribed promptly. As these diseases are rare, collaborative international epidemiological studies such as those being coordinated through the European Porphyria Network are essential to inform best clinical practice.

Neuropathic pain in a patient with porphyria. Case report

BACKGROUND AND OBJECTIVES

Porphyrias represent a group of inherited or acquired disorders that involve enzymes that participate in heme synthesis. Acute manifestations affect the nervous system resulting in abdominal pain, vomiting, acute neuropathy, seizures, and mental disorders. The physiopathogeny results from the toxic effects of porphyrin precursors, and it can be triggered by drugs used routinely in medical practice, severe carbohydrate restriction, and metabolic stress. The objective of this report was to present the case of a late onset porphyria evolving to chronic pain.

CASE REPORT

This is a 27 years old female who was admitted 5 months prior to her clinic appointment with severe abdominal pain without diagnosis. An exploratory laparotomy was indicated, which failed to demonstrate a cause for her pain. The patient was exposed to surgical trauma and drugs that can trigger porphyria, such as ketoprophen, metoclopramide, and antibiotics, and she evolved with significant hyponatremia, increased liver enzymes, seizures, and loss of movements that led to be admitted to the Intensive Care Unit. After the diagnosis of porphyria was made, the patient remained with pain in the lower limbs, being referred to the Pain Department of Santa Casa de Misericórdia de São Paulo. Treatment with amitriptyline, gabapentin, opioid, and simple analgesics was instituted; however, the patient continued to present recurring episodes of porphyria and, feeling insecure with the conduction of the case, she stopped the treatment.

CONCLUSIONS

Porphyria is one of the rare groups of enzymatic disorders that remain unknown by the great majority of health professionals. Upon recognizing this lack of knowledge about the disease, the level of stress and insecurity of the patient increases hindering adhesion to and continuity of the treatment.

Colon perforation secondary to porphyria

Acute intermittent porphyria (AIP) is a rare, inherited metabolic disorder of the haem biosynthesis pathway. The diagnosis is well known to cause significant diagnostic challenge due to its broad range of symptoms that may mimic many other conditions. We report a case of AIP that presented with caecal perforation, a clinical scenario that has not previously been reported in the literature.

Hepatic disorders severely affected by pregnancy: medical and obstetric management

Hepatic disorders severely affected by pregnancy include choledochal cysts that can be compressed by the gravid uterus and potentially rupture; hepatic adenomas that exhibit accelerated growth because of hyperestrogenemia during pregnancy; acute intermittent porphyria that is exacerbated by increased female sex hormones during pregnancy; splenic artery aneurysms that can rupture during pregnancy because of compression by the gravid uterus; Budd-Chiari syndrome that is promoted by hyperestrogenemia; and hepatitis E and herpes simplex hepatitis that are particularly severe during pregnancy. Hepatic disorders unique to pregnancy include intrahepatic cholestasis of pregnancy; acute fatty liver of pregnancy; preeclampsia and eclampsia; and hemolysis, elevated liver function tests, and low platelet count (HELLP) syndrome. Most disorders uniquely related to pregnancy are treated by prompt fetal delivery as soon as the fetus is sufficiently mature.

Immunosuppressive Therapy for Acute Porphyria: Safety and Efficacy in a Patient with Bone Marrow Failure

Acute intermittent porphyria is a rare disorder of heme biosynthesis with a clinical course characterized by exacerbations of neurologic symptoms. Drugs may precipitate these exacerbations; however, little is known about the safety of most drugs used to treat the disease. We describe a patient with acute intermittent porphyria who developed bone marrow failure and was successfully treated with cyclosporine. This agent has been reported as being unsafe for patients with acute intermittent porphyria based on an in vitro model. However, cyclosporine was used in this patient based on two published case reports of successful cyclosporine therapy in patients with acute intermittent porphyria undergoing kidney transplantation. Our patient tolerated cyclosporine well, and her blood counts demonstrated improvement. To our knowledge, this is the first case report of cyclosporine used for treatment of bone marrow failure in a patient with acute intermittent porphyria. Until more data are available, clinicians should consider immunosuppressive therapy as a safe option for treating certain patients with acute intermittent porphyria.

An analysis of six cases of acute intermittent porphyria (AIP)

This analysis describes the diagnosis and psychiatric treatment modalities of 6 patients (5 women, 1 man; mean age 28.5 years) of acute intermittent porphyria (AIP), who presented to the Psychiatry OPD over a period of one year. The mean number of episodes was 2.83. Premorbid personality traits, clinical presentation, urine colour and urinary porphobilinogen titre were recorded. Among the 6 patients, 4 had abdominal pain, 5 had autonomic instability, all 6 had mental symptoms, 3 had depression, 2 came in delirium, and 3 had an episode of seizure.

An analysis of 112 acute porphyric attacks in Cape Town, South Africa: Evidence that acute intermittent porphyria and variegate porphyria differ in susceptibility and severity

Four forms of porphyria may present clinically with the acute attack, an episodic, severe, and potentially life-threatening manifestation characterized by abdominal and neurologic symptoms. We describe our experience with 112 consecutive attacks observed and treated in 25 patients with the 2 most common forms of acute porphyria in Cape Town, South Africa; 25 attacks in 10 patients with variegate porphyria and 87 attacks in 14 patients with acute intermittent porphyria. The remaining patient experienced more than 100 sequential, severe, and poorly remitting attacks, which are not included in our analysis. In our population, the relative risk of an acute attack in acute intermittent porphyria compared with that in variegate porphyria was 14.3 (confidence intervals, 6.3-32.7). Patients with variegate porphyria were significantly older (median age at first attack, 30 yr) than those with acute intermittent porphyria (median age at first attack, 23.5 yr; p < 0.0001), and demonstrated an equal sex ratio, whereas the male:female ratio in acute intermittent porphyria was 2:12 (p < 0.0001). There was a significant difference in the incidence of factors precipitating the acute attack. Drug exposure was a frequent precipitant of the acute attack in variegate porphyria, whereas hormonal factors were more important in acute intermittent porphyria (p < 0.00001). Patients with acute intermittent porphyria also showed a trend to earlier and more frequent recurrent acute attacks following the initial admission. Mean urine precursor levels, blood pressure, pulse rate, and heme arginate requirement were all significantly higher in patients with acute intermittent porphyria. No significant difference in the frequency of serious complications or in outcome could be shown. We describe our experience with treatment with heme arginate, and provide evidence that heme arginate results in a prompt and statistically significant improvement in symptoms. The incidence of serious complications and mortality in this series was low, confirming a trend to an increasingly good prognosis for patients with acute porphyria who receive expert treatment.

Liver transplantation as a cure for acute intermittent porphyria

Acute intermittent porphyria occasionally causes frequent and crippling acute neurovisceral attacks associated with increased hepatic production of porphyrin precursors, resulting in long-term damage, poor quality of life, and shortened life expectancy. There has been no cure for this condition, but replacement of deficient hepatic enzymes might restore excretion of porphyrin precursors to normal and prevent acute attacks. We aimed to treat severe acute intermittent porphyria in a 19-year-old woman by liver transplantation. After the transplant, concentrations of haem precursors in the patient's urine returned to normal, and 1.5 years later her quality of life was good. Our report suggests some hope of cure for selected patients with severe forms of this disease.

Abdominal pain during pregnancy

Numerous medical, surgical, psychiatric, gynecologic, and obstetric disorders can cause abdominal pain during pregnancy. The patient history, physical examination, laboratory data, and radiologic findings usually provide the diagnosis. The pregnant woman has physiologic alterations that affect the clinical presentation, including atypical normative laboratory values. Abdominal ultrasound is generally the recommended radiologic imaging modality; roentgenograms are generally contraindicated during pregnancy because of radiation teratogenicity. Concerns about the fetus limit the pharmacotherapy. Maternal and fetal survival have recently increased in many life-threatening conditions, such as ectopic pregnancy, appendicitis, and eclampsia, because of improved diagnostic technology, better maternal and fetal monitoring, improved laparoscopic technology, and earlier therapy.

Ferriporphyrins and endothelium: a 2-edged sword—promotion of oxidation and induction of cytoprotectants

Heme arginate infusions blunt the symptoms of patients with acute intermittent porphyria without evidence of the vascular or thrombotic side effects reported for hematin. To provide a rationale for heme arginate's safety, the present study examined the effects of various ferriporphyrins to sensitize human endothelial cells to free radical injury and to induce heme oxygenase and ferritin expression. Heme arginate, unlike hematin, did not amplify oxidant-induced cytotoxicity mediated by hydrogen peroxide (5.3 ± 2.4 versus 62.3 ± 5.3% 51Cr release,P < .0001) or by activated neutrophils (14.4 ± 2.9 versus 41.1 ± 6.0%, P < .0001). Nevertheless, heme arginate efficiently entered endothelial cells similarly to hematin, since both markedly induced heme oxygenase mRNA (more than 20-fold increase) and enzyme activity. Even with efficient permeation, endothelial cell ferritin content was only minimally increased by heme arginate compared with a 10-fold induction by hematin; presumably less free iron was derived from heme arginate despite up-regulation of heme oxygenase. Hematin is potentially vasculopathic by its marked catalysis of oxidation of low-density lipoprotein (LDL) to endothelial-toxic moieties. Heme arginate was significantly less catalytic. Heme arginate–conditioned LDL was less than half as cytotoxic to endothelial cells as hematin-conditioned LDL (P < .004). It is concluded that heme arginate may be less vasculotoxic than hematin since it is an effective heme oxygenase gene regulator but a less efficient free-radical catalyst.

Ferriporphyrins and endothelium: a 2-edged sword—promotion of oxidation and induction of cytoprotectants

Heme arginate infusions blunt the symptoms of patients with acute intermittent porphyria without evidence of the vascular or thrombotic side effects reported for hematin. To provide a rationale for heme arginate's safety, the present study examined the effects of various ferriporphyrins to sensitize human endothelial cells to free radical injury and to induce heme oxygenase and ferritin expression. Heme arginate, unlike hematin, did not amplify oxidant-induced cytotoxicity mediated by hydrogen peroxide (5.3 ± 2.4 versus 62.3 ± 5.3% 51Cr release,P &lt; .0001) or by activated neutrophils (14.4 ± 2.9 versus 41.1 ± 6.0%, P &lt; .0001). Nevertheless, heme arginate efficiently entered endothelial cells similarly to hematin, since both markedly induced heme oxygenase mRNA (more than 20-fold increase) and enzyme activity. Even with efficient permeation, endothelial cell ferritin content was only minimally increased by heme arginate compared with a 10-fold induction by hematin; presumably less free iron was derived from heme arginate despite up-regulation of heme oxygenase. Hematin is potentially vasculopathic by its marked catalysis of oxidation of low-density lipoprotein (LDL) to endothelial-toxic moieties. Heme arginate was significantly less catalytic. Heme arginate–conditioned LDL was less than half as cytotoxic to endothelial cells as hematin-conditioned LDL (P &lt; .004). It is concluded that heme arginate may be less vasculotoxic than hematin since it is an effective heme oxygenase gene regulator but a less efficient free-radical catalyst.

Acute intermittent porphyria: biochemical and clinical analysis in the Argentinean population

Acute intermittent porphyria (AIP) is the most common type of hepatic acute porphyria. In this work, we have analyzed the biochemical data of all Argentinean AIP families studied in the Porphyrins and Porphyrias Research Centre (CIPYP). We have shown that: (i) the prevalence for this population is about 1:125,000; (ii) the disease is more frequent in women than in men (7:3); (iii) about 60% are latent carriers; (iv) 15% of patients with symptomatic AIP died during an acute attack; (v) the most important precipitating factors of acute attacks in our population were the ingestion of therapeutic drugs (25%), anesthetics in surgical interventions (25%) and infections (20%); (vi) the initial symptom in Argentinean AIP individuals is severe abdominal pain (100%), and it is often accompanied by constipation (37%), anorexia (37%) and tachycardia (30%); and (vii) the percentage of recurrence of the acute attacks is high (81%).

The acute porphyrias

The various types of acute porphyria are discussed, as well as their mode of inheritance and the enzyme deficiencies responsible for the symptoms. The symptoms and signs of an acute attack are then described, especially those due to neuropathies and to disturbances of behaviour. Agents which can precipitate attacks are listed. These are most frequently drugs, and as they include those used for anti-epileptic treatment problems soon arise as seizures often occur in this condition. The main complications are hypertension and renal failure, and examples of hyponatraemia and folate deficiency are illustrated. The urgency to diagnose this disorder lies in the need to avoid precipitating factors. Screening tests are discussed, and those needed to confirm the diagnosis. The prognosis has improved over the years, due to increased awareness of the disorder, and better management. During an acute attack the treatment of pain and vomiting will be of particular importance, and then haematin or chelating agents can be tried. With better management most of those who have inherited acute porphyria should be able to lead a normal life.