Urinary excretion of porphyrins in two cases of porphyria cutanea tarda during a period of various treatments.

The urinary excretion of porphyrins in two cases of porphyria cutanea tarda (PCT) has been followed during a period in which various treatments have been tried. In one patient pyridoxal-5-phosphate (P-5-P) injections lead to a dramatic increase in porphyrin excretion. In another P-5-P treatment was followed by a significant decrease in porphyrin excretion. p-Aminobenzoic acid (PABA) apparently had no effect on porphyrin excretion, while repeated phlebotomies had the expected effect. In both patients all variations in the total amount of porphyrins excreted were almost exclusively due to the variations in the amounts of heptacarboxylic porphyrin type III and uroporphyrin I. A secondary finding was an increase in hexa- and penta-carboxylic porphyrins type III without a concomitant increase in coproporphyrin III.     

Pseudoporphyria: a clinical and biochemical study of 20 patients

OBJECTIVE: To describe the clinical and laboratory findings in patients with pseudoporphyria. PATIENTS AND METHODS: This retrospective review identified 261 patients with either porphyrin metabolism abnormalities or pseudoporphyria who were seen at the Mayo Clinic in Rochester, Minn, between 1992 and 1996. All patients with documented porphyria cutanea tarda (PCT), noncutaneous porphyrias, or variegate porphyria were excluded. RESULTS: Twenty patients had active cutaneous lesions resembling PCT with no diagnostic laboratory abnormalities. The major presenting clinical features were blistering in 19 patients (95%), scarring in 14 (70%), photosensitivity in 13 (65%), skin fragility in 13 (65%), and milia in 8 (40%). Histologically, of 17 patients tested, 12 (71%) had classic findings of subepidermal separation with festooning of dermal papillae. None of the 11 patients tested had hepatitis B or C. In all 20 patients, porphyrin profiles were nondiagnostic. Of 16 patients for whom follow-up was available, 11 reported persistent symptoms for a mean of 2.5 years after evaluation. Five patients were free of symptoms 1 week to 6 months after discontinuation of the presumed offending agent. CONCLUSION: Pseudoporphyria mimics the cutaneous symptoms of PCT in the setting of normal or near-normal porphyrin levels in the serum, urine, or stool. Despite efforts to discontinue an offending medication, symptoms may persist indefinitely.     

Porphyria cutanea tarda and chronic renal failure

Bullous dermatosis developed in a patient with renal failure who was on hemodialysis. The results of standard tests for porphyria cutanea tarda--quantitation of urinary and fecal porphyrins by fluorometric assay--were within normal limits or were nondiagnostic. Assay of plasma using high-pressure liquid chromatography, however, revealed that this patient had a porphyrin profile consistent with porphyria cutanea tarda. A porphyria-like bullous eruption may occur in patients with chronic renal failure; however, in only a few cases have laboratory studies confirmed the diagnosis of porphyria cutanea tarda. Our experience suggests that, in patients with renal failure, a plasma assay may be more reliable than tests of the urine and feces in establishing a diagnosis in those patients who actually have disorders of porphyrin metabolism. We also report the results of assay of erythrocyte uroporphyrinogen decarboxylase activity and fecal isocoproporphyrin.     

The Ether Soluble Porphyrins Found in Urine in Acute Porphyria and Porphyria Cutanea Tarda

1. The ether soluble porphyrins in the urine of one case of porphyria cutanea tarda and two cases of acute porphyria have been studied and compared with the ether soluble porphyrins from normal man, and it has been shown that the porphyrin pattern in porphyria cutanea tarda differs from that of acute porphyria and normal man in that the amounts of porphyrins with 5-7 carboxylic

2. The isomer pattern of coproporphyrin has been found to be the same in all conditions studied. The main isomer is the III isomer, with approximately 40 per cent I isomer and trace amounts of a porphyrin behaving like the II isomer of coproporphyrin.

3. The 3 and 5 carboxylic porphyrins have each been split by paper chromatography into two distinct spots with approximately the same amount of porphyrin in each spot.

4. The possible implication of these findings have been discussed, and it is suggested that the coproprphyrin isomer pattern found is due to the isomerization of excess formed coproporphyrinogen III during the biosynthesis of heme. The possibility that small amounts of the I series may be formed under physiological conditions has not, however, been excluded.

5. It is further suggested that the presence of approximately equal amounts of 5 and 3 carboxylic porphyrins is due not to the presence of porphyrins of the I11 and I series but to the random decarboxylation of the side chains of the normal tetrapyrrolic intermediates.     

Direct spectrofluorometry of diluted erythrocytes and plasma: a rapid diagnostic method in primary and secondary porphyrinemias.

Primary and secondary porphyrinemias are characterized by the presence of several porphyrin species in erythrocytes and/or plasma. Acid solvent extraction of porphyrins from natural ligands can preclude observation of significant spectral differences apparent on direct spectrofluorometric examination of porphyrin complexes in tissue. Erythrocytes and hemoglobin-free plasma obtained from 13 patients with erythropoietic, 9 with lead intoxication, 5 with porphyria cutanea tarda, 3 with iron deficiency anemia, 1 with erythropoietic porphyria, and 10 normal persons were simply diluted and analyzed spectrofluorometrically. Characteristic porphyrin-ligand spectral patterns were consistently obtained for each group of specimens, allowing diagnostic application of the data.     

On accuracy and precision of a HPLC method for measurement of urine porphyrin concentrations.

We studied the accuracy and precision of a HPLC method for determination of porphyrins in urine. A commercial standard solution appeared to contain less porphyrins than indicated by the manufacturer, since calibration resulted in lower concentrations of uroporphyrin and coproporphyrin: 16% and 8%, respectively. Coefficients of variation for the measurement of uro-, hepta-, copro I and copro III porphyrins in samples of patients with and without porphyria were often much less than 15%. Comparison of measurements with and without calibrated standards revealed differences for uroporphyrin and coproporphyrin of 27% and 5%, respectively. Recovery of added uroporphyrin and coproporphyrin was 99%. The main cause of the variability in test results was apparently the improperly calibrated standard solutions. The precision of porphyrin measurements was not influenced by the type of porphyria.     

Studies on porphyrin biosynthesis in lead-intoxicated rabbits

The present report deals with studies on porphyrins and porphyrinogen carboxylyase of red cells and urinary porphyrins from lead-intoxicated rabbits.It was shown that the free erythrocyte porphyrins are a mixture of protoporphyrin 9, the main component, and minor proportions of Coproporphyrin, Uroporphyrin III and Phyriaporphyrin.Analysis of the urinary porphyrins demonstrates the presence of Coproporphyrin III as the major component, together with 15–20% of other porphyrins: 10–14% 5-COOH, 1–2% 6-COOH, 2–3% 7-COOH porphyrin and 1–2% Uroporphyrin III. We have not been able to detect an increase of Uroporphyrin I.Assays of porphyrinogen carboxy-lyase activity in hemolysate supernatant using Uroporphyrinogen III and Phyriaporphyrinogen (Phyria'gen) III as substrates, showed the existence of a slight decrease of both decarboxylase activities, being more affected during the second stage, the Phyria'gen decarboxylation.A possible regulation mechanism responsible for the porphyrin picture is discussed.     

Rapid Changes in Human Right Heart Blood Temperature at Variations in Venous Return

Abstract

Quantitative determinations were made of coproporphyrin (CP) and protoporphyrin (PP) in the feces from 26 patients with porphyria acuta intermittens (PAI), from 26 patients with porphyria cutanea tarda (PCT), and from 32 workers in the lead industry.

In about 4/5 of the PAI-patients the fecal excretion of CP was slightly increased, while almost half of them had a slightly increased excretion of PP. The ratio between PP and CP was normal, namely 6:1.

of the patients with PCT, all showed an increased excretion of CP. Three-fifths of them also showed an increased excretion of PP. The excretion of CP was higher than among the patients with PA1 and the ratio PP/CP was about 1.

Fecal excretion of porphyrins in the lead-workers was largely normal.

The difference in the excretion patterns of porphyrins and their precursors in the urine and feces in PAI, PCT and in lead intoxication is elucidated.     

Urinary porphyrin excretion in hepatitis C infection.

A high prevalence of hepatitis C virus infection in porphyria cutanea tarda in some populations suggests a close link between viral hepatitis and alteration of porphyrin metabolism. Moreover, there is evidence of a role of porphyrinopathies in hepatocarcinogenesis. The aim of our study was to obtain data on the prevalence and patterns of heme metabolism alterations in patients with chronic hepatitis C virus infection. Urinary porphyrin excretion was prospectively studied in 100 consecutive outpatients with chronic hepatitis C infection without signs of photosensitivity, using an ion-pair high-performance liquid chromatography method. Increased total porphyrin excretion was found in 41 patients, with predominant excretion of coproporphyrins (whole study group: mean 146 microg/g creatinine, interquartile range 76-186; normal < 150), in 10 patients excretion exceeded 300 microg/g creatinine. In the majority of all patients studied (75/100) an increased ratio of the relatively hydrophobic coproporphyrin isomer I to isomer III was found. In just one case, urinary porphyrin pattern characteristic for chronic hepatic porphyria was present (uroporphyrin > coproporphyrin, heptacarboxyporphyrin III increased) but the total porphyrin excretion was only slightly elevated in this case. In the whole group, total urinary porphyrin excretion correlated well with serum bilirubin and was inversely correlated with albumin and thrombin time. In conclusion, secondary coproporphyrinuria occurs frequently in heptatitis C infection, whereas in Germany, preclinical porphyria cutanea tarda seems to be rare in these patients.     

Early-onset chronic renal failure as a complication of acute intermittent porphyria

In a retrospective survey of patients who have had a proven attack of acute intermittent porphyria (AIP) in the West of Scotland a highly significant association (p less than 0.001) was observed between AIP and the development of early-onset chronic renal failure. Six patients with AIP and chronic renal failure arising in early middle-age are described. As no other cause could be attributed to the renal failure three possible causal links between these two conditions were considered, namely, enhanced susceptibility to analgesic nephropathy, porphyria-induced hypertension, and nephrotoxic effects of porphyrins and their precursors. We suggest that porphyria-induced hypertension is the most important factor in causing early-onset chronic renal failure in acute intermittent porphyria.     

Biochemical differentiation of the porphyrias

Objectives: To differentiate the porphyrias by clinical and biochemical methods.

Design and methods: We describe levels of blood, urine, and fecal porphyrins and their precursors in the porphyrias and present an algorithm for their biochemical differentiation. Diagnoses were established using clinical and biochemical data. Porphyrin analyses were performed by high performance liquid chromatography.

Results and conclusions: Plasma and urine porphyrin patterns were useful for diagnosis of porphyria cutanea tarda, but not the acute porphyrias. Erythropoietic protoporphyria was confirmed by erythrocyte protoporphyrin assay and erythrocyte fluorescence. Acute intermittent porphyria was diagnosed by increases in urine delta-aminolevulinic acid and porphobilinogen and confirmed by reduced erythrocyte porphobilinogen deaminase activity and normal or near-normal stool porphyrins. Variegate porphyria and hereditary coproporphyria were diagnosed by their characteristic stool porphyrin patterns. This appears to be the most convenient diagnostic approach until molecular abnormalities become more extensively defined and more widely available.     

Stimulation of 5-aminolevulinic acid metabolism by uroporphyrinogen I in rat liver homogenate

The effect of excess uroporphyrinogens I and III, coproporphyrinogen III, and the corresponding porphyrins, on the rate of 4-14C-5-aminolevulinic acid (ALA) metabolism was studied. Experiments were performed with mitochondria-free rat liver homogenates prepared from normal rats. The consumption of labelled 5-aminolevulinic acid was followed by measuring its level in aliquots removed at intervals. The pattern of porphyrinogen synthesis was examined by high pressure liquid chromatography. Only uroporphyrinogen I had an effect; it increased the rate of conversion of ALA and porphobilinogen (PBG) to porphyrinogens. Chromatographic analysis revealed increased synthesis of uroporphyrinogen and heptacarboxylic porphyrinogen. It is believed that this mechanism might explain the lack of ALA and PBG accumulation in erythropoietic porphyria and porphyria cutanea tarda, and the absence of acute porphyria attacks in these conditions.     

Improvement in HPLC separation of porphyrin isomers and application to biochemical diagnosis of porphyrias.

BACKGROUND: Identification of porphyrias relies on the measurement of different porphyrins in urine, feces and plasma. Separation of porphyrin isomers is essential for the differential diagnosis of some porphyrias. METHOD: Separation of naturally occurring porphyrins was achieved on a Chromolith RP-18 column with fluorimetric detection using a methanol/ammonium acetate gradient mobile phase. Fecal and plasma porphyrins were extracted with acetonitrile and water at different pH values. RESULTS: Eight porphyrins including protoporphyrin eluted within 20 min with good resolution of each of the I and III positional isomer pairs for standards, urine and plasma, and within 50 min for feces. Improvement of the extraction method for fecal and plasmatic porphyrins resulted in high recovery (up to 89%) and reliable quantification of protoporphyrin. CONCLUSIONS: The present RP-HPLC method is specific and efficient for routine analysis of porphyrins in human urine, feces and plasma.     

Procalcitonin and C-reactive protein plasma concentrations in nonseptic uremic patients undergoing hemodialysis

OBJECTIVE: To assess procalcitonin (PCT) and C-reactive protein (CRP) plasma concentrations and clearance in nonseptic end-stage renal failure patients undergoing their first three hemodialysis sessions. DESIGN AND SETTING: Prospective observational consecutive clinical study at a university hospital. PATIENTS: The study recruited 55 end-stage renal failure patients without evidence of systemic infection undergoing the creation of an arteriovenous fistula to start hemodialysis for the first time. INTERVENTIONS: Blood samples were collected before and after each of the first three (4-5 h) hemodialysis sessions. PCT was assayed by immunoluminometry. MEASUREMENTS AND RESULTS: The mean plasma concentration of PCT prior to the first three hemodialysis sessions declined significantly following each session. There was no significant difference between CRP plasma concentrations before and after hemodialysis sessions. CONCLUSIONS: The presence of an elevated PCT in plasma of not yet dialyzed uremic nonseptic patients indicates that uremia per se and not the dialysis process is the origin of such elevation. PCT levels declined with successive hemodialysis sessions. We propose that in the not yet dialyzed uremic nonseptic patients a baseline PCT level of approx. 1.5 ng/ml should be expected. Although the mean plasma CRP level was elevated, hemodialysis had no significant effect on CRP concentration, making CRP a possible useful marker of sepsis in these patients.     

Early-Onset Chronic Renal Failure as a Complication of Acute Intermittent Porphyria

In a retrospective survey of patients who have had a provenattack of acute intermittent porphyria (AIP) in the West ofScotland a highly significant association (p < 0·001)was observed between AIP and the development of early-onsetchronic renal failure. Six patients with AIP and chronic renalfailure arising in early middle-age are described. As no othercause could be attributed to the renal failure three possiblecausal links between these two conditions were considered, namely,enhanced susceptibility to analgesic nephropathy, porphyria-inducedhypertension, and nephrotoxic effects of porphyrins and theirprecursors. We suggest that porphyria-induced hypertension isthe most important factor in causing early-onset chronic renalfailure in acute intermittent porphyria     

Plasma concentrations and clearance of procalcitonin during continuous veno-venous hemofiltration in septic patients

We determined the elimination characteristics of procalcitonin (PCT) during continuous veno-venous hemofiltration (CVVHF) and the resulting effect on PCT plasma levels. A prospective study was conducted in patients with sepsis and acute oliguric renal failure, treated with CVVHF using a polysulfone membrane (Baxter Renaflo II PSHF 1200). Patients had sepsis and PCT plasma levels > 4 ng ml(-1) (n = 26). PCT was measured in the pre- and post-filter plasma and the ultrafiltrate at 0, 5, 10, and 15 min and 1, 2, 4, 6, 12, and 24 h after setup of CVVHF. PCT sieving coefficient was 0.24. Elimination of PCT, however, depended on the duration of filtration, because filter adsorption was the main mechanism of PCT clearance during the first hour of hemofiltration, finally increasing to a clearance of PCT into the ultrafiltrate of 2.8-5.5 mL/min after 2 h. PCT plasma levels were not significantly altered during CVVHF (96% of the initial concentration after 24 h, P = 0.72). Similar to what has been observed with cytokines and other proteins of a comparable molecular weight, PCT is removed from the plasma during CVVHF, but plasma PCT levels are unchanged. Thus, PCT can be used as a diagnostic parameter even in patients with acute renal failure undergoing CVVHF.     

Rapid procedure for fecal porphyrin assay

Hydrochloric acid extraction of feces in the presence of ether yields an extract suitable for spectrophotometric estimation of total porphyrin and for further separation by "high-performance" liquid chromatography (HPLC) or thin-layer chromatography. A total porphyrin reference interval of less than 200 nmol/g dry weight of feces was established from data on 106 normal subjects on an unrestricted diet. Total fecal porphyrin values in 11 porphyria cutanea tarda patients were considerably higher than given by the widely used Rimington method (respective means, 652 and 239 nmol/g dry weight). Our HPLC method for separation of porphyrin methyl esters on a silica column, with quantification by fluorescence, is described. HPLC separations performed on 23 porphyria cutanea tarda patients gave the following mean proportions of total fecal porphyrins: dicarboxylics 21%, coproporphyrin 9%, isocoproporphyrins 28%, pentacarboxylporphyrin 9%, hexacarboxylporphyrin 11%, heptacarboxylporphyrin 18%, and uroporphyrin 4%.     

Genetics and pathogenesis of human uroporphyrinogen decarboxylase defects

Two types of human porphyria, porphyria cutanea tarda (PCT) and hepatoerythropoietic porphyria (HEP), result from partial deficiency of uroporphyrinogen decarboxylase (UROD). About 20% of patients with PCT have a 50% decrease in UROD concentration in all tissues that is inherited as an autosomal dominant trait with low penetrance (type II PCT). Both this condition and its postulated homozygous counterpart, HEP, show genetic heterogeneity. Identification of a form of familial PCT in which the activity and concentration of erythrocyte UROD is normal, as in type I or sporadic PCT, suggests than an autosomal gene, not necessarily at the UROD locus, may be important in determining the onset of type I PCT. Clinically overt PCT results from a liver-specific process that causes reversible inactivation of UROD and which may be iron dependent. The predisposition to develop PCT in response to common hepatotoxic agents and other acquired factors may be determined by interaction between genes that control the concentration of active UROD in cells and genes that facilitate the inactivation process.     

Variegate Porphyria: TWELVE YEARS' EXPERIENCE IN FINLAND

Fifty-seven patients with variegate porphyria belonging to ninefamilies are described. The prevalence of variegate porphyriain Finland is 1·3 per 100 000. Eighteen patients hadhadacute attacks. During on average 5·7 years' follow-uponly two of 48 patients had symptoms, which were temporary andacute. The length of life of 13 genealogically traced gene carrierswho lived mostly during the 19th century did not differ fromthat of the general population. Skin fragility occurred in 45per cent of the patients and was usually mild. No patients weresensitive to sunlight but seven of 14 tested reacted abnormallyto artificial light. The characteristic increase in the excretionof faecal proto and coproporphyrin was usually apparent evenin the latent stage of porhyria, but increased excretion ofurinary porphyrin precursors occurred only during an acute attack.However, in seven of 48 patients studied during the latent stage,faecal porphyrins were only slightly elevated or even normal,causing problems in diagnosis. Determination of faecal X-porphyrinwas of no help in diagnosis. Red cell free protoporphyrin wassignificantly higher and serum haemopexin lower than in controls.Red cell uroporphyrinogen I synthase activity was normal in17 of 18 patients studied. We concluded that variegate porphyria may be commoner than hithertosuspected; only half the patients in temperate and cold climateshave skin symptoms, the risk of developing an acute attack islow, and some adult patients excrete normal or only slightlyabnormal amounts of porphyrin.     

Hereditary coproporphyria in Germany: clinical-biochemical studies in 53 patients

OBJECTIVES: To describe the biochemical and clinical features in hereditary coproporphyria (HCP). DESIGN AND METHOD: Within the last 20 years, we investigated 53 patients (male:female = 1:2.5; age = 8-86 years) suffering from HCP. We describe the characteristic levels of urine, and fecal porphyrins and their precursors in hereditary coproporphyria and present the clinical features. Especially, we measured the coproporphyrin isomers I and III. RESULTS AND CONCLUSION: The group of hereditary coproporphyria patients exhibited a significantly higher (p<0.0001) excretion of urinary porphyrin precursors, delta-aminolevulinic acid (median = 84 micromol/24 h) and porphobilinogen (median = 39 micromol/24 h), as compared to controls (delta-aminolevulinic acid: 22 micromol/24 h, porphobilinogen: 3 micromol/24 h; median, n = 20). The median of coproporphyrin in urine (1315 nmol/24 h) and feces (1855 nmol/g) were enhanced 12- and 168-fold, as compared to healthy subjects (urinary coproporphyrin: 106 nmol/24 h, fecal coproporphyrin: 11 nmol/g; median, n = 20). During therapy on one female patient, with IV application of heme arginate, a considerable decline of porphyrin precursors and porphyrin excretion was observed. The examination of urinary and fecal coproporphyrin isomers I and III revealed an excessive elevation of the coproporphyrin isomer III of 87% in urine and 94% in feces, respectively (normal: urinary isomer III = 69-83% and fecal isomer III = 25-40%). In feces the increase of isomer III caused an inversion of the physiologic coproporphyrin isomer III:I ratio that could be recognized in all various stages in hereditary coproporphyria and in children. Acute attacks of hereditary coproporphyria are accompanied by an acute polysymptomatic clinical syndrome, and this is associated with high levels of urinary porphyrin precursors. On review of our patients, the highest percentage had abdominal pain (89%), followed by neurologic (33%), psychiatric (28%), cardiovascular (25%), and skin symptoms (14%).