Serum erythropoietin levels may be inappropriately low in the acute neuropsychiatric porphyrias

BACKGROUND

Patients with the acute porphyrias may develop renal failure and autonomic dysfunction. Renal damage and sympathetic failure may both cause erythropoietin (EPO) deficiency. In this study, we have investigated serum erythropoietin levels and autonomic function in patients with acute porphyria in clinical remission.

METHODS

Serum erythropoietin levels and the corresponding haemoglobin (Hb) were assayed in 31 patients with acute porphyria and were compared to 15 type 1 diabetic patients with autonomic neuropathy, 23 patients with iron-deficiency anaemia and 18 healthy individuals.

RESULTS

9 out of 31 porphyric patients showed a normochromic normocytic anaemia with normal ferritin levels. Three patients had borderline-raised serum creatinine levels, and one of them was anaemic. Autonomic function was investigated in seven patients, six of them being anaemic, and the results were normal. Patients with iron-deficiency anaemia showed the expected increase in serum erythropoietin levels in response to a decreasing haemoglobin (r=-0.86, p<0.001). Patients with porphyria had inappropriately low serum erythropoietin levels for the degree of anaemia compared to iron-deficiency patients (p<0.001) although there was still a significant increase in serum erythropoietin with decreasing haemoglobin levels (r=-0.46, p=0.01). In contrast, diabetic autonomic neuropathy patients demonstrated a significant decrease in serum erythropoietin with decreasing Hb levels (r=+0.53, p=0.05).

CONCLUSIONS

Patients with acute porphyria may have inappropriately low levels of EPO. In contrast to the diabetic patients, this does not appear to be due to autonomic neuropathy but it may reflect mild renal tubular impairment.

Respiratory failure in acute intermittent porphyria

We report two patients of acute intermittent porphyria (AIP) who presented with acute respiratory failure. Only one such previous report could be found. Occasionally, neuropathy may be the presenting feature in AIP which may progress to respiratory embarrassment. The cause of this neuropathy has been hypothesized to be direct neurotoxicity of delta-ALA by interaction with GABA receptor, altered tryptophan metabolism and may be heme depletion in nerve cells.

Is 5-aminolevulinic acid involved in the hepatocellular carcinogenesis of acute intermittent porphyria?

5-Aminolevulinic acid (ALA) is a heme precursor that accumulates in acute intermittent porphyria (AIP) due to enzymatic deficiencies in the heme biosynthetic pathway Its accumulation has been associated with several symptoms, such as abdominal pain attacks, neuromuscular weaknesses, neuropsychiatric alterations and increased hepatocellular carcinoma (HCC) incidence. The use of exogenous ALA to elevate porphyrin levels in tumor photodynamic therapy, adds further significance to ALA toxicology. Under ferritin mediated and metal catalyzed oxidation, ALA produces reactive oxygen species that can damage plasmid and isolated DNA in vitro, and increases the steady-state level of 8-oxo-7,8-dihydro-2'-deoxyguanosine in liver, spleen and kidney DNA and 5-hydroxy-2'-deoxycytidine in liver DNA of ALA-treated rats. The in vitro DNA damage could be partially inhibited by SOD, catalase, DTPA, mannitol and melatonin. ALA also promotes the formation of radical-induced base degradation products in isolated DNA. 4,5-Dioxovaleric acid, the final oxidation product of ALA, alkylates guanine moieties within both nucleoside and isolated DNA, producing two diastereoisomeric adducts. Dihydropyrazine derivatives of ALA generated by its dimerization, promote DNA strand-breaks and 8-oxodGuo formation in the presence of Cu2+. Together these results reinforce the hypothesis that the DNA damage induced by ALA may be associated with the development of HCC in individuals suffering from AIP.

Acute intermittent porphyria as a cause of acute respiratory failure

A fatal case of acute intermittent porphyria in a 22 years old Indian male is reported. He presented with abdominal pain and constipation, subsequently developed status epilepticus, acute respiratory failure and quadriparesis. He succumbed to the illness on the twelfth day. Among the neuromuscular causes of acute respiratory failure, requiring ventilatory support, porphyria is a condition potentially treatable, but rarely suspected.

[Diabetic metabolism protective in severe acute intermittent porphyria]

In AIP attacks there is an escalating metabolic chain reaction leading to heme deficiency and increased levels of porphyrin precursors. This reaction is inhibited by treatment with glucose or heme arginate. In a population-based study in the two most northerly counties of Sweden (Norrbotten and Västerbotten), out of 319 patients > 18 years of age with DNA-verified AIP, 16 had type-2 diabetes. None of the 16 patients showed AIP symptoms after the onset of their diabetes. Three patients had suffered recurrent, severe attacks for many years, but after onset of diabetes their ALA and PBG levels decreased and the AIP symptoms resolved, to the relief of the patients. In a study of the 30 AIP patients with hepatocellular carcinoma (HCC) none had diabetes. This implies that diabetic metabolism may prevent the development of HCC in patients with AIP. The prevalence of AIP patients with diabetes was lower than the prevalence of diabetic patients in the general population. This study shows that diabetes mellitus may be beneficial for patients with severe AIP.

MR imaging of acute intermittent porphyria mimicking reversible posterior leukoencephalopathy syndrome

Reversible posterior leukoencephalopathy syndrome (PLS) is characterized by headache, altered mental function, visual disturbances and seizures. Neuroimaging studies suggest a white-matter oedema, predominantly in the posterior parietal-temporal-occipital regions of the brain. We present the case of a 30-year-old woman who had suffered her first attack of acute intermittent porphyria (AIP). Following 1 week of abdominal pain she developed several generalized seizures, and hallucinations, and exhibited a progressive deterioration of the consciousness. T2-weighted images, especially fluid-attenuated inversion recovery (FLAIR) sequences showed bilateral lesions in the posterior frontal, parietal and occipital cortex and subcortical white matter. Following treatment with haematin and a high carbohydrate diet the patient's condition improved. Follow-up magnetic resonance imaging (MRI) revealed complete resolution of the lesions. To our knowledge, this is the first report concerning a completely reversible PLS in AIP.

[Recurrent abdominal pain caused by acute intermittent porphyria]

BACKGROUND

Acute intermittent porphyria is an inherited metabolic disorder which may remain undiagnosed throughout life unless appropriate biochemical analysis is being performed during an acute attack.

MATERIALS, METHOD AND RESULTS

We describe a 26-year-old woman who had been suffering from recurrent abdominal pain for many years. She had been hospitalized several times; her appendix had been removed, and three diagnostic laparoscopies and several gynaecological procedures had not revealed the cause. During an intractable and increasing abdominal pain episode, porphyrins were detected in her urine. Her pain was then treated effectively with a combination of morphine, glucose and haem-arginat infusion.

INTERPRETATION

In a patient suffering from repeated episodes of unexplainable abdominal colic, paresis or psychic symptoms, acute intermittent porphyria should be considered as a diagnosis.

[Neuropathy of the lower legs and feet in acute intermittent porphyria. A comparison of patients with type 1 diabetes and patients with AIP]

Distal neuropathy was assessed in 339 patients with acute intermittent porphyria (AIP). The chronic neurological signs were symmetrical and similar to those in Type 1 diabetic patients. Significant impairment was found concerning perception, extensor digitorum brevis test, lower leg pain, ankle and knee tendon reflexes but not concerning dry feet, loss of forefoot arch and hammer toes, when comparing patients with manifest vs. latent AIP. The neurological signs were more severe in the diabetic patients (n = 298). Five AIP patients had permanent quadriplegia and renal failure after severe attacks. Patients with manifest AIP had significantly more signs of distal chronic, symmetrical neuropathy of axonal type than had patients with latent AIP. More serious neurological lesions appear to develop after severe attacks.

Use of gonadotropin-releasing hormone analog with tibolone to prevent cyclic attacks of acute intermittent porphyria

A 25-year-old woman with a 10-year history of recurrent attacks of acute abdominal pain just before menstrual periods had acute intermittent porphyria (AIP) diagnosed when she was 23.5 years old. Many acute attacks required hospitalization. Suppression of the menstrual cycle with a gonadotropin-releasing hormone analog (GnRHa; triptorelin) and tibolone administration as add-back therapy resulted in absence of acute porphyric attacks. The patient had no acute attacks over a 1-year follow-up period. This case suggests that long-term GnRHa therapy with tibolone add-back may be a therapeutic option for patients with AIP.

Porphyrias associated with malignant tumors: results of treatment with ionizing irradiation

BACKGROUND

Porphyrin metabolism disorders, known as porphyria, represent inherited or acquired diseases. The development of porphyria due to light sensibility occurs especially with exposure to wavelengths in the range of 300-700 nm. Skin reactions and neurovisceral dysfunctions are known side effects of ionizing irradiation. It can be postulated that during or after ionizing irradiation treatment of patients affected with tumor and porphyria, severe side effects might appear, in contrast to patients without porphyria. This paper describes the treatment of 2 patients affected with tumor and concomitant porphyria.

PATIENTS

One female patient suffering from intermittent porphyria and breast cancer and one male patient suffering from porphyria cutanea tarda and bladder cancer were treated with ionizing irradiation (electrons and photons). No abnormalities nor any severe general or local side effects could be observed.

CONCLUSION

Radiation therapy is not a 'stimulating' factor in activating porphyria symptoms.

[Unsatisfactory pain treatment in attacks of acute intermittent porphyria. Vasodilation an alternative if the pain is shown to be the pain of intestinal angina]

Abdominal pain is by far the most serious symptom in attacks of acute intermittent porphyria (AIP). Its cause is unknown. This case suggests visceral ischemia as a possible cause of the abdominal pain. A 31-year-old woman with recurrent bouts died during an attack; the autopsy revealed a 20 cm necrotic gangrene in the ileum. A protracted intestinal vasospasm could have been the immediate cause of death. The question as to whether intestinal angina could be the cause of abdominal pain in acute intermittent porphyria is discussed.

The tolerability of newer immunosuppressive medications in a patient with acute intermittent porphyria

Acute intermittent porphyria results from a deficiency of the porphobilinogen deaminase enzyme of heme biosynthesis and is commonly exacerbated by a wide variety of medications. When referred a patient with acute intermittent porphyria for a renal transplant, only steroids and azathioprine were discovered as safe in patients with acute intermittent porphyria. The administration of many newer immunosuppressive medications, including calcineurin inhibitors, has not been documented in acute intermittent porphyria. Actually, cyclosporine is presently considered contraindicated in acute intermittent porphyria. To determine if calcineurin inhibitors would be tolerated in acute intermittent porphyria, cyclosporine and tacrolimus were administered pretransplant and were documented not to exacerbate acute intermittent porphyria. A successful renal transplant was then performed using tacrolimus. This is the first reported patient with documented acute intermittent porphyria to tolerate safely several of the newer immunosuppressive medications, including tacrolimus, mycophenolate, and rabbit antithymocytic globulin following renal transplantation. This patient's pretransplant evaluation also suggested that cyclosporine may be safe for some patients with acute intermittent porphyria.

Melatonin and epileptic seizures in patients with acute intermittent porphyria

The objective of this study was to assess melatonin production in patients with acute intermittent porphyria (AIP), with and without known epileptic seizures, as a guide to whether melatonin may have anti-convulsive or pro-convulsive effects in AIP. Melatonin concentration in urine, sampled over eight hours on two consecutive nights, was analysed in eight AIP patients with epileptic seizures and in 14 AIP relatives without epilepsy. The AIP patients with epileptic seizures had a significantly lower urinary excretion of melatonin, compared with their AIP relatives without epilepsy, which may indicate that melatonin has a protective effect on seizures.

Renal symptomatology in patients with acute intermittent porphyria. A population-based study

OBJECTIVE

Can renal insufficiency in subjects with acute intermittent porphyria (AIP) be due solely to

DESIGN

A population-based study.

SUBJECTS

Subjects with AIP > or = 18 years of age (n = 386) in the four most northerly counties of Sweden.

INTERVENTIONS

Screening with creatinine clearance at 24 h. Patients below the lower reference level underwent a repeat clearance test and, if still low, also chromEDTA clearance.

RESULTS

286 (74%) subjects performed the creatinine clearance test and in 57 clearance was low; the second clearance proved normal in 23 who were then excluded. Eighteen subjects with other possible medical reasons for renal insufficiency, ethical reasons or refusing further examinations were also excluded. The 16 remaining subjects with no explanation for their renal insufficiency other than AIP were then studied in detail. All 14 women, mean age 52 years, and two uraemic men, 58 and 67 years, had manifest AIP. Twelve patients had hypertension (HT) and four were normotensive in spite of renal insufficiency. Histological findings of renal biopsies revealed diffuse glomerulosclerotic and interstitial changes with additional ischaemic lesions.

CONCLUSION

Protracted vasospasm in attacks of AIP may be a cause of renal lesions. This is discussed.

Prevalence of acute intermittent porphyria in a Mexican psychiatric population

BACKGROUND

Acute intermittent porphyria is a hereditary error of porphyrin metabolism in which the main metabolic defect is caused by a decrease in porphobilinogen deaminase activity. Previous work has demonstrated a higher prevalence of acute intermittent porphyria in the psychiatric patient population than in the general population. The goal of this study was evaluate 300 psychiatric patients and 150 control subjects to detect acute intermittent porphyria by measurement of porphobilinogen (PBG) deaminase activity in blood.

METHODS

Screening for porphobilinogen deaminase activity was carried out by fluorometric measurement of porphyrins synthesized during 1 h in blood and the measurement of delta-aminolevulinic acid and porphobilinogen in urine.

RESULTS

We found two psychiatric patients, one male and one female, with decreased porphobilinogen deaminase activity. When the families of these patients were studied, one brother was found to have an abnormality. Among controls, a woman was found to have the abnormality and her father was found to have typical features of the disease.

CONCLUSIONS

These results indicate a prevalence of porphyria in Mexican psychiatric patients similar to controls, and that measurement of PBG deaminase activity is a good tool for defining acute intermittent porphyria carriers.

Signs of neuropathy in the lower legs and feet of patients with acute intermittent porphyria

OBJECTIVE

To assess signs of distal neuropathy in patients with acute intermittent porphyria (AIP).

DESIGN

A population-based study.

SUBJECTS

All patients with DNA-verified AIP >/= 18 years of age in the four most northerly counties of Sweden.

INTERVENTION

Validated neuropathic signs and tests such as monofilament test, neuropathic pain, dry feet, extensor digitorum brevis (EDB) test, loss of forefoot arch, hammer toes and ulceration.

RESULTS

A total of 356 patients were registered and 339 of them (95%) participated in the neuropathy study. The chronic neurological signs were symmetrical and similar to those in type 1 diabetic patients. Significant impairment was found concerning perception, EDB test, lower leg pain, ankle and knee tendon reflexes, but not concerning dry feet, loss of forefoot arch and hammer toes, on comparing patients with manifest versus latent AIP. The neurological signs were more severe in the diabetic patients (n = 298). Five AIP patients had permanent quadriplegia after severe attacks.

CONCLUSIONS

Patients with manifest AIP had significantly more signs of distal chronic, symmetrical neuropathy of axonal type than did patients with latent AIP. More grave neurological lesions appear to develop after severe attacks.

Could attacks of abdominal pain in cases of acute intermittent porphyria be due to intestinal angina?

Abdominal pain is by far the most serious symptom in attacks of acute intermittent porphyria. Its cause is unknown. This case study suggests visceral ischaemia as a possible cause of the abdominal pain. A 31-year-old woman with recurrent bouts died during an attack; the autopsy revealed a 20-cm necrotic gangrene in the ileum. A protracted intestinal vasospasm could have been the immediate cause of death. It is discussed whether intestinal angina could be the cause of the abdominal pain in acute intermittent porphyria.