Effectiveness and tolerability of givosiran for the management of acute hepatic porphyria: A monocenter real-life evaluation.

Acute hepatic porphyrias (AHPs) are a family of rare, autosomal, dominantly inherited conditions characterized by abnormalities in the production of heme. Advances in molecular engineering have provided new therapeutic possibilities for modifying the heme synthetic pathway in patients with porphyria. In particular, the RNA interference therapeutic givosiran was approved for the treatment of adults and adolescents with AHP aged >12 years based on the positive results of the phase III trial ENVISION. Despite the extended characterization of the activity of givosiran in clinical trials, reports on the long-term effects and effectiveness of the treatment in clinical practice are still scant. To fill this gap, this case series describes a monocentric Italian cohort of AHP patients treated with givosiran. Overall, our real-life experience supports the clinical evidence that long-term treatment with givosiran is well tolerated and able to provide sustained and continuous benefit to patients with acute intermittent porphyria, as reflected by the reduction in the frequency of attacks. In our series, givosiran treatment was also associated with improvement in assessments of quality of life, pain and fatigue.

Intrahepatic Cholangiocarcinoma and Acute Intermittent Porphyria: A Case Report.

Patients suffering from different forms of acute hepatic porphyria present a high risk of primary liver cancer, specifically hepatocellular carcinoma and cholangiocarcinoma, determined by the activity of the disease even though an exact mechanism of carcinogenesis has not been recognized yet. Here, we present the clinical case of a 72-year-old woman who, approximately 29 years after the diagnosis of acute intermittent porphyria, presented with intrahepatic cholangiocarcinoma with a histological diagnosis of adenocarcinoma starting from the biliary-pancreatic ducts, which was diagnosed during the clinical and anatomopathological evaluation of a pathological fracture of the femur.

Circadian Genes Expression Patterns in Disorders Due to Enzyme Deficiencies in the Heme Biosynthetic Pathway.

Heme is a member of the porphyrins family of cyclic tetrapyrroles and influences various cell processes and signalling pathways. Enzyme deficiencies in the heme biosynthetic pathway provoke rare human inherited metabolic diseases called porphyrias. Protein levels and activity of enzymes involved in the heme biosynthetic pathway and especially 5'-Aminolevulinate Synthase 1 are featured by 24-h rhythmic oscillations driven by the biological clock. Heme biosynthesis and circadian pathways intermingle with mutual modulatory roles. Notably, heme is a ligand of important cogs of the molecular clockwork, which upon heme binding recruit co-repressors and inhibit the transcription of numerous genes enriching metabolic pathways and encoding functional proteins bringing on crucial cell processes. Herein, we assessed mRNA levels of circadian genes in patients suffering from porphyrias and found several modifications of core clock genes and clock-controlled genes expression, associated with metabolic and electrolytic changes. Overall, our results show an altered expression of circadian genes accompanying heme biosynthesis disorders and confirm the need to deepen the knowledge of the mechanisms through which the alteration of the circadian clock circuitry could take part in determining signs and symptoms of porphyria patients and then again could represent a target for innovative therapeutic strategies.

Kidney Involvement in Acute Hepatic Porphyrias: Pathophysiology and Diagnostic Implications.

Porphyrias are a group of rare disorders originating from an enzyme dysfunction in the pathway of heme biosynthesis. Depending on the specific enzyme involved, porphyrias manifest under drastically different clinical pictures. The most dramatic presentation of the four congenital acute hepatic porphyrias (AHPs: acute intermittent porphyria-AIP, ALAD deficiency, hereditary coproporphyria-HCP, and porphyria variegata-VP) consists of potentially life-threatening neurovisceral attacks, for which givosiran, a novel and effective siRNA-based therapeutic, has recently been licensed. Nonetheless, the clinical manifestations of acute porphyrias are multifaceted and do not limit themselves to acute attacks. In particular, porphyria-associated kidney disease (PAKD) is a distinct, long-term degenerating condition with specific pathological and clinical features, for which a satisfactory treatment is not available yet. In PAKD, chronic tubule-interstitial damage has been most commonly reported, though other pathologic features (e.g., chronic fibrous intimal hyperplasia) are consistent findings. Given the relevant role of the kidney in porphyrin metabolism, the mechanisms possibly intervening in causing renal damage in AHPs are different: among others, δ-aminolevulinic acid (ALA)-induced oxidative damage on mitochondria, intracellular toxic aggregation of porphyrins in proximal tubular cells, and derangements in the delicate microcirculatory balances of the kidney might be implicated. The presence of a variant of the human peptide transporter 2 (PEPT2), with a greater affinity to its substrates (including ALA), might confer a greater susceptibility to kidney damage in patients with AHPs. Furthermore, a possible effect of givosiran in worsening kidney function has been observed. In sum, the diagnostic workup of AHPs should always include a baseline evaluation of renal function, and periodic monitoring of the progression of kidney disease in patients with AHPs is strongly recommended. This review outlines the role of the kidney in porphyrin metabolism, the available evidence in support of the current etiologic and pathogenetic hypotheses, and the known clinical features of renal involvement in acute hepatic porphyrias.

[Between old and new targets: blood pressure control in hypertensive outpatients].

OBJECTIVE: In developed countries, blood pressure (BP) control has increased over the past few decades and is now approaching 70% of patients. Herewith we report the results of a cross-sectional study carried out on hypertensive outpatients. DESIGN AND METHODS: In a cohort of 1,412 consecutive hypertensive outpatients (790 females, 622 males; mean age: 60.3±12.2 years) evaluated from January 2015 to December 2016, the following parameters were assessed: age, gender, body mass index (BMI), waist circumference (WC), smoking habits, BP in the sitting position, estimated glomerular filtration rate (eGFR), serum glucose, lipid profile, antihypertensive drugs prescribed. In agreement with the European guidelines, hypertension was defined as sitting BP ≥140/90 mmHg or use of antihypertensive drugs. Patients whose BP was <140/90 mmHg were considered as having achieved BP control. Furthermore, in compliance with the redefinition of hypertension suggested by the American College of Cardiology/American Heart Association (ACC/AHA), a second level of BP control (BP <130/80 mmHg) was evaluated. RESULTS: Overall, 75.7% of hypertensive patients achieved BP levels <140/90 mmHg, while 50.5% achieved BP levels <130/80 mmHg. In both contexts, compared with patients whose BP was not controlled, those achieving the BP targets were mainly younger and females with a lower prevalence of obesity, diabetes and chronic kidney disease. Furthermore, they also had a lower WC and a higher eGFR. CONCLUSIONS: Nearly 76% of patients achieved the BP target of <140/90 mmHg, a result which is higher than the 70% achieved in Europe, and 50.6% achieved that of <130/80 mmHg, a result which is slightly higher than the 47% recently reported in USA.

Brain perfusion defects by SPET/CT and neurostat semi-quantitative analysis in two patients with congenital erythropoietic porphyria.

BACKGROUND: Congenital erythropoietic porphyria (CEP) is a rare autosomal recessively inherited disorder with chronic and relatively stable presentation. Till now brain blood flow derangements have been described only in acute hepatic porphyrias. We describe the first findings of brain perfusion defects, studied by single photon emission tomography/computed tomography (SPET/CT), in two patients affected by CEP, by using a semi-quantification anatomic-standardized voxel-based program compared with magnetic resonance imaging (MRI) results. SUBJECTS AND METHODS: Two Pakistanis brothers were investigated for CEP confirmed by a genetic test. The disease was severe with: skin burning, mood depression and haemolytic anemia. Considering depression, patients underwent brain SPET/CT and MRI. Single photon emission tomography/CT images were processed by neurostat semi-quantitative software. Data obtained were compared to a normal database and z-score images were generated. RESULTS: In both patients we found several perfusion defects evident in transaxial slices and in z-score images obtained by neurostat processing. Magnetic resonance imaging was negative in both patients. Biochemical mechanisms inducing localized brain hypoperfusion are uncertain. However, mismatch between SPET/CT data and MRI was probably due to absence of necrosis. CONCLUSION: In our opinion, SPET/CT could have a key role in this setting of patients due to its high sensitivity and reliability in mild-to-moderate brain perfusion defects detection. Moreover, the quantitative analysis by using neurostat may allow to recognize even mild brain perfusion alterations, difficult to detect only visually.

Cerebral Hypoperfusion in Hereditary Coproporphyria (HCP): A Single Photon Emission Computed Tomography (SPECT) Study.

BACKGROUND: Hereditary Coproporphyria (HCP) is characterized by abdominal pain, neurologic symptoms and psychiatric disorders, even if it might remain asymptomatic. The pathophysiology of both neurologic and psychiatric symptoms is not fully understood. Therefore, aiming to evaluate a possible role of brain blood flow disorders, we have retrospectively investigated cerebral perfusion patterns in Single Photon Emission Computed Tomography (SPECT) studies in HCP patients. MATERIALS & METHODS: We retrospectively evaluated the medical records of patients diagnosed as being affected by HCP. A total of seven HCP patients had been submitted to brain perfusion SPECT study with 99mTc-Exametazime (hexamethylpropyleneamine oxime, HMPAO) or with its functionally equivalent 99mTc-Bicisate (ECD or Neurolite) according with common procedures. In 3 patients the scintigraphic study had been repeated for a second time after the first evaluation at 3, 10 and 20 months, respectively. All the studied subjects had been also submitted to an electromyographic and a Magnetic Resonance Imaging (MRI) study of the brain. RESULTS: Mild to moderate perfusion defects were detected in temporal lobes (all 7 patients), frontal lobes (6 patients) and parietal lobes (4 patients). Occipital lobe, basal ganglia and cerebellar involvement were never observed. In the three subjects in which SPECT study was repeated, some recovery of hypo-perfused areas and appearance of new perfusion defects in other brain regions have been found. In all patients electromyography resulted normal and MRI detected few unspecific gliotic lesions only in one patient. Discussion & Conclusions: Since perfusion abnormalities were usually mild to moderate, this can probably explain the normal pattern observed at MRI studies. Compared to MRI, SPECT with 99mTc showed higher sensitivity in HCP patients. Changes observed in HCP patients who had more than one study suggest that transient perfusion defects might be due to a brain artery spasm possibly leading to psychiatric and neurologic symptomatology, as already observed in patients affected by acute intermittent porphyria. This observation, if confirmed by other well designed studies aiming to demonstrate a direct link between artery spasm, perfusion defects and related symptoms could lead to improvements in HCP treatments.

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).

How to assess renal function in the geriatric population.

The progressive decline of renal function with aging is not inevitable, because it is mainly due to comorbid conditions such as hypertension and diabetes. However, in the elderly there is a high prevalence of chronic kidney disease leading to the need for strategies to control cardiovascular risk - death being far more common than dialysis at all stages of kidney function. Serum creatinine, the most widely used surrogate marker of glomerular filtration rate (GFR), is inaccurate with increasing age, particularly in sick and/or malnourished elderly people; it shows the so-called creatinine blind area, and substantial variation between laboratory analytical methods. An alternative endogenous marker is serum cystatin C: it correlates better with renal function and has the potential advantage of improved precision of the assay, but its measurement is still much more expensive. Current guidelines recommend that the 2 most commonly used equations to estimate GFR - the Modification of Diet in Renal Disease Study or Cockcroft-Gault equations - be used to estimate GFR in the clinical setting. Both show relevant bias, with underestimation of GFR in subjects with normal or mild renal impairment, a bias limited by using the more recent Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Nonetheless, keeping in mind that a decreased renal function in the elderly is not benign, current GFR equations facilitate detection, evaluation and management of the disease, and they should result in improved patient care and better clinical outcomes.