Role of PIGM and PIGX in glycosylphosphatidylinositol biosynthesis and human health (Review).

Glycosylphosphatidylinositol-glycan (GPI) is an anchor to specific cell surface proteins known as GPI-anchored proteins (APs) that are localized in lipid rafts and may act as cell co-receptors, enzymes and adhesion molecules. The present review investigated the significance of GPI biosynthesis class phosphatidylinositol-glycan (PIG)M and PIGX in GPI synthesis and their implications in human health conditions. PIGM encodes GPI-mannosyltransferase I (MT-I) enzyme that adds the first mannose to the GPI core structure. PIGX encodes the regulatory subunit of GPI-MT-I. The present review summarizes characteristics of the coding sequences of PIGM and PIGX, and their expression in humans, as well as the relevance of GPI-MT-I and the regulatory subunit in maintaining the presence of GPI-APs on the cell surface and their secretion. In addition, the association of PIGM mutations with paroxysmal nocturnal hemoglobinuria and certain types of GPI-deficiency disease and the altered expression of PIGM and PIGX in cancer were also reviewed. In addition, their interaction with other proteins was described, suggesting a complex role in cell biology. PIGM and PIGX are critical genes for GPI synthesis. Understanding gene and protein regulation may provide valuable insights into the role of GPI-APs in cellular processes.

The spectrum of paroxysmal nocturnal hemoglobinuria clinical presentation in a Brazilian single referral center.

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare hematological disorder caused by the expansion of a hematopoietic clone harboring a somatic genetic variant in the PIG-A gene translating into a wide spectrum of clinical and laboratory changes, from intravascular hemolysis, thrombosis, and bone marrow failure to subclinical presentation. In this study, we retrospectively analyzed 87 consecutive cases (39 women; median follow-up, 18 months; range, 0-151 months) in whom a PNH clone was detected by flow cytometry between 2006 and 2019 seen at a single Brazilian referral center. The median age at diagnosis was 29 years (range, 8 to 83 years); 29 patients (33%) were initially classified as PNH/bone marrow failure, 13 (15%) as classic PNH, and 45 (52%) as subclinical PNH. The median overall survival (OS) of the entire cohort was not reached during follow-up, without significant differences between groups. At diagnosis, the median PNH clone size was 2.8% (range, 0 to 65%) in erythrocytes and 5.4% (range, 0 to 80%) in neutrophils. Fourteen patients experienced clone expansion during follow-up; in other 14 patients the clone disappeared, and in 18 patients it remained stable throughout the follow-up. A subclinical PNH clone was detected in three telomeropathy patients at diagnosis, but it was persistent and confirmed by DNA sequencing in only one case. In conclusion, PNH presentation was variable, and most patients had subclinical disease or associated with marrow failure and did not require specific anticomplement therapy. Clone size was stable or even disappeared in most cases.

Cost-Utility Analysis of Eculizumab for the Treatment of Paroxysmal Nocturnal Hemoglobinuria From the Perspective of the Brazilian Public Health System.

OBJECTIVE: To perform a first cost-utility analysis of eculizumab for the treatment of paroxysmal nocturnal hemoglobinuria from the perspective of the Brazilian Unified Health System. METHODS: A Markov decision model was developed for 35-year-old patients with symptomatic paroxysmal nocturnal hemoglobinuria. We used a cycle length of one month and a time horizon of 20 years. The effectiveness measure was the quality-adjusted life year (QALY). Data were extracted from clinical trials, historical cohorts, and Unified Health System databases. Resource use and costs were estimated from the perspective of the Unified Health System. Deterministic and probabilistic sensitivity analyses were performed. RESULTS: The estimated gain in effectiveness with the use of eculizumab was 1.08 QALY through the incremental cost of R$10,959,375.95. The incremental cost-effectiveness ratio was R$10,139,542.84 per QALY, being 331.92 times greater than the Brazilian gross domestic product per capita. In the deterministic sensitivity analysis, the parameters related to the utilities of health states were associated with greater impact in the model. The results of the probabilistic sensitivity analysis with 1000 simulations evidence that 100% of the simulations were not considered cost-effective with the arbitrated willingness to pay R$30,548.40 and R$91,645.20 per QALY. CONCLUSIONS: The gain in effectiveness with the use of eculizumab was modest, associated with an unjustifiable incremental cost. Therefore, eculizumab is not a cost-effective drug compared with the current standard of care in the treatment of paroxysmal nocturnal hemoglobinuria from the Brazilian Unified Health System perspective.

Dental infection associated with exuberant gingival necrosis in a patient with paroxysmal nocturnal hemoglobinuria: A case report.

Paroxysmal nocturnal hemoglobinuria (PNH) is a hematological disorder that affects hematopoietic stem cells. An association with other hematological diseases, such as hemolytic anemia and neutropenia, is observed with a high occurrence of aplastic anemia. The aim of the present study is to report a case of dental infection in a patient with PNH exhibiting exuberant gingival involvement. A 45-year-old male patient sought the Federal University of Ceara reporting severe toothache associated with tooth 24. Clinical examination revealed that the tooth was associated with an apparent fistula and a yellowish lesion with smooth surface located in the palate. The patient had interrupted the medication to control PNH. Blood transfusion was requested due to deficient hematological parameters. Tooth extraction and excisional biopsy were performed under antibiotic coverage. In the postoperative period, low-level laser therapy (LLLT) was performed. Histopathological examination revealed connective tissue showing extensive necrotic areas, accumulation of basophilic material, numerous cyst-like cavities, and degenerated cells. Histopathological findings were compatible with the initial clinical diagnosis of gingival necrosis. The patient evolved with febrile neutropenia, requiring hospitalization for 1 month. Improvement in the overall health was observed after the administration of antibiotics, eculizumab, and weekly LLLT at the biopsy site.

Paroxysmal nocturnal hemoglobinuria: Test to monitor the action of eculizumab treatment.

INTRODUCTION: Paroxysmal nocturnal hemoglobinuria (PNH) is caused by a somatic mutation in the PIG-A gene, which encodes for glycosylphosphatidylinositol, a phospholipid membrane that anchors proteins like CD55 and CD59. These proteins are inhibitors of the complement-mediated lysis. PNH is diagnosed by flow cytometry, and treatment with eculizumab improves the life quality of patients with severe clinical compromise. The aim of this work was to evaluate a hemolytic test that allows monitoring the blockade of the alternative complement pathway caused by eculizumab (herein MET test). METHODS: There were analyzed a total of 163 serum samples from nine patients with PNH under treatment with eculizumab and ten healthy volunteers like controls. The patients were evaluated for 6 months. The MET test consisted in incubating red blood cells from patients (RBCPNH ) with either acidified serum from healthy volunteers and from patients with PNH. The results can be (a) Positive, (b) Blockade profile, or (c) Negative. RESULTS: Seven patients responded favorably to the eculizumab, and the test evidenced the blockade profile. The two remaining patients were nonresponders to the treatment, with a positive MET test. In these patients, the dose was increased. One responded favorably with a blockade profile, and the other continued to be nonresponder. CONCLUSIONS: The MET test proved to be a useful tool to monitor the blockade of complement by eculizumab.

Hemoglobinuria paroxística nocturna: revisión de la literatura / Paroxysmal nocturnal hemoglobinuria: literature Review

La hemoglobinuria paroxística nocturna (HPN) es una enfermedad clonal y adquirida causada por una mutación somática en el gen PIG-A que se encuentra en el cromosoma X y codifica una proteína involucrada en la síntesis del glicosilfosfatidilinositol (GPI), el cual le sirve como anclaje a muchas proteínas de la membrana celular produciendo mayor sensibilidad al complemento. Los distintos signos y síntomas que se presentan tienen gran impacto en la calidad de vida de los pacientes, por lo que un diagnóstico correcto es de vital importancia. Actualmente, la citometría de flujo multiparamétrica es la metodología de elección para detectar y seguir al paciente con HPN.

Paroxysmal nocturnal hemoglobinuria (PNH) is a clonal and acquired disease caused by a somatic mutation in the PIG-A gene found on the X chromosome and encoding a protein involved in the synthesis of glycosylphosphatidylinositol (GPI), which serves as anchoring to many proteins of the cell membrane producing greater sensitivity to complement. The different signs and symptoms that appear have a great impact on the quality of life of patients, so a correct diagnosis is of vital importance. Currently, multiparameter flow cytometry is the methodology of choice to detect and follow the patient with PNH.

Hemoglobinuria paroxística nocturna y absceso hepático: asociación poco frecuente / Paroxysmal nocturnal hemoglobinuria and hepatic abscess: A little frequent association

Resumen: La hemoglobinuria paroxística nocturna es un trastorno adquirido de las células madre hematopoyéticas que se caracteriza por episodios de hemólisis intravascular. Aunque es una enfermedad poco frecuente, afecta en su mayor parte a adultos jóvenes, sin distinción de sexo. Comunicamos el caso de un paciente de 32 años de edad, que acudió a consulta con cuadro clínico de palidez, ictericia, hemoglobinuria y dolor en el hipocondrio derecho. El estudio de citometría de flujo de médula ósea reportó la ausencia de marcadores CD55 y CD59, indicativos del diagnóstico de hemoglobinuria paroxística nocturna, además de una imagen tomográfica hipodensa en el hígado compatible con absceso. En la bibliografía médica éste es el primer caso en el que se describe la coexistencia de estas dos afecciones.

Abstract: Paroxysmal nocturnal hemoglobinuria is an acquired disorder of hematopoietic stem cells characterized by episodes of intravascular hemolysis. Although it is a rare disease, it mostly affects young adults, regardless of sex. We present the case of a 32-year-old man with acute symptoms of paleness, jaundice, hemoglobinuria and pain in the right hypochondrium. The study of flow cytometry of bone marrow reported the absence of CD55 and CD59 markers, diagnostic indicators of nocturnal paroxysmal hemoglobinuria in addition to a hypodense tomographic image in the liver compatible with abscess. In the medical literature, this is the first case in which the coexistence of these two medical conditions is described.

Off-Pump Coronary Revascularization Using Bilateral Internal Thoracic Arteries in A Patient with Paroxysmal Nocturnal Hemoglobinuria: A Case Report.

Paroxysmal nocturnal hemoglobinuria (PNH) is an ultra-orphan disease. We report the first case in the literature of Off-Pump Coronary Revascularization Using Bilateral Internal Thoracic Arteries in a patient with paroxysmal nocturnal hemoglobinuria. A 36-year-old man came to the emergency department with acute non-ST elevation myocardial infarction (NSTEMI). He presented paroxysmal nocturnal hemoglobinuria diagnosed in 2016. Coronary angiography revealed tripple vessel disease. The conduits used for coronary revascularization were both internal thoracic arteries (left ITA-right ITA [LITA-RITA]). We consider that off-pump coronary artery bypass grafting (OPCABG) using Bilateral Internal Thoracic Arteries (BITA) can be safely performed with low in-hospital mortality and complications rates, even in patient with PNH.

Off-Pump coronary revascularization using bilateral internal thoracic arteries in a patient with paroxysmal nocturnal hemoglobinuria: a case report

Abstract Paroxysmal nocturnal hemoglobinuria (PNH) is an ultra-orphan disease. We report the first case in the literature of Off-Pump Coronary Revascularization Using Bilateral Internal Thoracic Arteries in a patient with paroxysmal nocturnal hemoglobinuria. A 36-year-old man came to the emergency department with acute non-ST elevation myocardial infarction (NSTEMI). He presented paroxysmal nocturnal hemoglobinuria diagnosed in 2016. Coronary angiography revealed tripple vessel disease. The conduits used for coronary revascularization were both internal thoracic arteries (left ITA-right ITA [LITA-RITA]). We consider that off-pump coronary artery bypass grafting (OPCABG) using Bilateral Internal Thoracic Arteries (BITA) can be safely performed with low in-hospital mortality and complications rates, even in patient with PNH.

Diagnóstico por citometría de flujo de la hemoglobinuria paroxística nocturna / Diagnosis of paroxysmal nocturnal hemoglobinuria by flow cytometry

Introducción: La hemoglobinuria paroxística (HPN) nocturna es una enfermedad clonal, adquirida y no maligna de la célula madre hematopoyética. En este padecimiento se encuentra afectado el anclaje a la membrana celular de moléculas como el CD55 y CD59, fundamentales en la regulación de la lisis mediada por el complemento. Por su elevada especificidad y sensibilidad, la citometría de flujo multiparamétrica (CFM) es el método de elección para el diagnóstico de esta enfermedad. Objetivo: Establecer un algoritmo diagnóstico de la HPN por CMF. Métodos: Se analizó una muestra de sangre periférica para CFM de un paciente con sospecha de HPN. El inmunofenotipaje celular se realizó con un panel de anticuerpos monoclonales dirigidos contra los antígenos que se expresan en la membrana citoplasmática mediante su anclaje al glicosilfosfatidilinositol. Las muestras se leyeron en un citómetro GALLIOS, Beckman Coulter y los datos obtenidos se analizaron con el empleo del programa informático Kaluza. Resultados: Se identificaron cuatro clones HPN. En los granulocitos se observó un clon HPN de aproximadamente 90 por ciento, con deficiencia en la expresión de CD16, CD24, CD55 y CD59. En los monocitos se observaron dos clones: (1) clon CD14_CD59_ y (2) clon CD14_CD59+ con tamaños clonales de 59,77 por ciento y 19,45 por ciento, respectivamente. En los eritrocitos se identificó un clon de 19,98 por ciento y de determinó el grado de afectación. Conclusiones: El algoritmo de análisis propuesto permite identificar las poblaciones celulares con clones HPN. Además, dichos clones pueden ser cuantificados en cuanto a tamaño clonal y expresividad de los antígenos dependientes de anclaje a glicosilfosfatidilinositol. Con la CFM se logra determinar con elevada sensibilidad el grado de afectación de los eritrocitos en la expresión de CD59 como medida directa de la susceptibilidad que experimentan a la lisis por el complemento(AU)

Introduction: The paroxysmal nocturnal hemoglobinuria (PNH) is a clonal, acquired disease and not malignant hematopoietic stem cell. In this condition, the anchor to the cell membrane of molecules such as the CD55 and CD59 is affected, This antigens are fundamental in the regulation of the complement-mediated lysis. By its high specificity and sensitivity multiparametric flow cytometry (MFC) is the goal standard for the diagnosis of this disease. Objective: To establish a diagnosis of PNH by MFC algorithm. Methods: A sample of peripheral blood of a patient with suspicion of PNH was analyzed by MFC. The cell immunophenotyping was carried out using a panel of monoclonal antibodies directed against antigens that are expressed in the cytoplasmic membrane through its the glycosylphosphatidylinositol anchor. The samples were read in a Cytometer GALLIOS, Beckman Coulter and the data obtained were analyzed with the use of the Kaluza software. Results: We identified four clones HPN. A HPN clone of approximately 90 percent, was observed in granulocytes with deficiency in the expression of CD16, CD24, CD55, CD59. In the monocytes were two clones: (1) CD14-CD59- clone and (2) CD14-CD59 + clone, with size clone of 59.77 percent and 19.45 percent, respectively. A clone of 19.98 percent was identified in erythrocytes and determined the degree of involvement of the same. Conclusions: The proposed analysis algorithm allows to identify cellular populations with clones PNH. In addition, these clones can be quantified in terms of size clonal and expressiveness of anchor to glycosylphosphatidylinositol antigen dependent. With the MFC is achieved with high sensitivity to determine the degree of involvement of the erythrocytes in the expression of CD59 as a direct measure of susceptibility undergoing lysis by complement(AU)

Hemoglobinuria paroxística nocturna. el rol de la anhidrasa carbónica-i urinaria en la hemólisis intravascular / Peroxysmal nocturnal hemoglobinuria: the role of urinary carbonic anhydrase-I in intravascular haemolysis

La Hemoglobinuria Paroxística Nocturna (HPN) se caracteriza por hemólisis intravascular crónica mediada por complemento. Cuando se produce la hemolisis se libera a circulación Anhidrasa Carbónica- I (AC-I), una enzima que se halla en alta concentración en el eritrocito y por su bajo peso molecular filtra por el glomérulo. El objetivo del presente trabajo fue detectar la excreción de la AC-I en orina de pacientes con HPN por Electroforesis Bidimensional de Utilidad Clínica (2D UC), y compararla con otras causas de hemólisis, de origen renal y postrenal. Se evaluaron 8 pacientes con HPN sin tratamiento con eculizumab un inhibidor del C5 del complemento, y 5 de ellos postratamiento, 12 orinas de pacientes con nefritis lúpica y 10 orinas de pacientes con hemólisis postrenal. La AC-I puede estar presente en la orina, en los tres grupos, sin embargo la relación AC-I/Hemoglobina en la hemólisis intravascular está invertida en comparación con la hemolisis glomerular y post-renal. Los pacientes con HPN tratados con eculizumab no presentan AC-I, y sería de utilidad en el seguimiento de los pacientes tratados con el inhibidor del C5, para evidenciar posibles escapes hemolíticos.

Paroxysmal Nocturnal Hemoglobinuria (PNH) is characterized by chronic complement mediated haemolysis. In these conditions it might be expected that carbonic anhydrase-I (AC-I) would be liberated into the plasma and excreted in the urine, by its high concentration in the erythrocyte and low molecular weight. The objective of the present study was to detect the urinary excretion of AC-I from patients with PNH by wodimensional clinical utility electrophoresis (2D UC) and to compare it with other causes of renal and post-renal haemolysis. We evaluated 8 patients with PNH without eculizumab, a complement C5 inhibitor, 5 of them posttreatment, 12 urine of patients with lupus nephritis and 10 urine of patients with post-renal hemolysis. AC-I may be present in the urine, in all three groups, however, the AC-I/Haemoglobin ratio in intravascular haemolysis is reversed compared to glomerular and post-renal haemolysis. Patients with PNH treated with eculizumab do not have AC-I and would be useful in monitoring patients treated with the C5 inhibitor to evidence possible haemolytic leaks.

Multiple Lacunar Infarcts in Paroxysmal Nocturnal Hemoglobinuria.

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare acquired disease characterized by clonal hematopoietic stem cell disorder, with increased mortality and morbidity. Venous thrombosis is the most common cause of mortality in PNH. The relationship between PNH and cerebrovascular disease is unclear; few cases are reported in the literature, most of them related to cerebral venous thrombosis; In PNH the involvement of intracranial and extracranial arterial sites is very rare. We report a case of a 49-year-old woman who has a medical history of diabetes mellitus, hypertension, and PNH and presented multiple lacunar strokes in a routine consultation with a hematologist. A brain computed tomography (CT) scan showed lacunar infarcts, and magnetic resonance image showed acute ischemic stroke, multiple territory lacunar infarctions, and focal area of microbleeds in gradient echo sequence. A CT angiography showed V3 and V4 branches of the left vertebral artery occluded by a thrombus, and the posterior inferior cerebellar artery occluded, whereas the carotid system was normal. We discuss the presentation and physiopathology of stroke in PNH and other cases reported in the literature review.

Hemoglobinuria paroxística nocturna / Paroxysmal nocturnal hemoglobinuria

ResumenLa hemoglobinuria paroxística nocturna es una anemia hemolítica crónica, adquirida, poco común, que afecta con igual frecuencia ambos sexos. Se manifiesta a cualquier edad y con mayor incidencia en países del sudeste asiático. Es el resultado de la expansión clonal no maligna de células progenitoras hematopoyéticas. Se caracteriza por anemia hemolítica intravascular, tendencia a la trombosis y un componente variable de insuficiencia medular.Se asocia a otras patologías hematológicas como anemia aplásica y síndrome mielodisplásico. La citometría de flujo es el método de elección para diagnóstico. El eculizumab y el trasplante de médula ósea alogénico son las únicas terapias efectivas.

Abstract:Paroxysmal nocturnal hemoglobinuria is a rare acquired chronic hemolytic anemia, which affects both sexes with equal frequency. It occurs at any age and more frequently in Southeast Asian countries. It is the result of non malignant clonal expansion of hematopoietic progenitor cells. It is characterized by intravascular hemolytic anemia, recurrent thrombosis and a variable component of bone marrow failure. It is associated with other hematologic disorders such as aplastic anemia and myelodysplastic syndrome. Flow cytometry is the method of choice for diagnosis. Eculizumab and allogeneic bone marrow transplantation is the only effective therapies.

Detecção de células com fenótipo HPN por citometria de fluxo, utilizando análise multiparamétrica / Detection of PNH cells by flow cytometry, using multiparameter analysis

Introduction: The laboratory diagnosis of paroxysmal nocturnal hemoglobinuria (PNH), disease that is categorized by reduced synthesis of glycosylphosphatidylinositol (GPI) anchor, is based on the detection of blood cells deficient in GPI-anchored proteins by flow cytometry. PNH clones have been detected in patients with aplastic anaemia (AA) and myelodysplastic syndrome (MDS), with therapeutic implications. Objectives: To validate a sensitive assay for detection of GPI-anchored protein-deficient cells, by flow cytometry, and to analyze the clone frequency in AA and MDS patients. Methods: Samples from 20 AA patients, 30 MDS patients and 20 adult volunteers (control group) were analyzed using monoclonal antibodies to CD16, CD24, CD55 and CD59 (neutrophils); CD14 and CD55 (monocytes); CD55 and CD59 (erythrocytes); besides fluorescent aerolysin reagent (FLAER) (neutrophils and monocytes) and lineage markers. The proportions of PNH cells detected in neutrophils and monocytes, using different reagent combinations, were compared by analysis of variance (ANOVA) and Pearson's correlation. Results: PNH cells were detected in five (25%) AA patients, and the proportions of PNH cells varied from 0.14% to 94.84% of the analyzed events. PNH cells were not detected in the MDS patients. However, by the analysis of these samples, it was possible to identify the technical challenges caused by the presence of immature and dysplastic circulating cells. FLAER showed clear distinction of GPI-deficient cells. Conclusion: Multiparameter flow cytometry analysis offers high sensitivity and accuracy in the detection of subclinical PNH clones. FLAER shows excellent performance in detection of PNH neutrophils and monocytes...

Introdução: O diagnóstico laboratorial da hemoglobinúria paroxística noturna (HPN), doença caracterizada por deficiência de síntese da molécula de ancoragem glicosilfosfatidilinositol (GPI), baseia-se na detecção de células sanguíneas deficientes em proteínas ancoradas ao GPI, por citometria de fluxo. Clones de células com fenótipo HPN podem ser detectados em pacientes com anemia aplásica (AA) e síndrome mielodisplásica (SMD), com implicações terapêuticas. Objetivos: Validar técnica sensível para detecção de células HPN, por citometria de fluxo, e avaliar a frequência dos clones em pacientes com AA e SMD. Métodos: Amostras de 20 pacientes com AA, 30 pacientes com SMD e 20 voluntários (controles) foram analisadas, utilizando anticorpos monoclonais anti-CD16, CD24, CD55 e CD59 (neutrófilos); CD14 e CD55 (monócitos); e CD55 e CD59 (hemácias); além do reagente de aerolisina fluorescente (FLAER) (neutrófilos e monócitos) e marcadores de linhagem celular. A comparação do tamanho dos clones HPN detectados em neutrófilos e monócitos, pelas diferentes combinações de reagentes, foi realizada por análise de variância (ANOVA) e correlação de Pearson. Resultados: Em cinco (25%) pacientes com AA foram identificadas células HPN, em proporções entre 0,14% e 94,84% dos eventos analisados. O clone não foi detectado nos pacientes com SMD. Contudo, a análise dessas amostras permitiu evidenciar as dificuldades técnicas secundárias à presença de células imaturas e displásicas circulantes. O reagente FLAER propiciou separação precisa das células alteradas. Conclusão: A análise multiparamétrica por citometria de fluxo apresenta sensibilidade...

Hemoglobinuria paroxística nocturna: de Strübing al Eculizumab / Paroxysmal nocturnal hemoglobinuria: from Strübing to Eculizumab

La hemoglobinuria paroxística nocturna (HPN) es un trastorno clonal severo y raro no maligno y adquirido de la célula madre hematopoyética. Es el único trastorno hemolítico adquirido causado por una anomalía de la membrana eritrocitaria como resultado de una mutación somática clonal de un gen, el fosfatidilinositol glucano clase A (PIG-A) situado en el brazo corto del cromosoma X. Se han identificado una serie de proteínas reguladoras del complemento, entre las que se destacan: el factor acelerador de la degradación (CD55) y el factor inhibidor de la lisis reactiva de la membrana (CD 59) deficientes en esta enfermedad. La HPN se clasifica en clásica, asociada a otro trastorno medular y en subclínica. Su diagnóstico se apoya en estudios hematológicos, bioquímicos, pruebas serológicas especiales, estudios eritroferrocinéticos e imagenológicos. La electroforesis de proteínas de membrana de alta resolución y la citometría de flujo multiparamétrica constituyen técnicas de elección para el diagnóstico. El tratamiento de la anemia, de los episodios trombóticos y de las infecciones constituyen los pilares terapéuticos básicos. Dentro de los agentes farmacológicos más utilizados se destacan: los esteroides. los andrógenos, la eritropoyetina recombinante humana y el factor estimulador de colonias granulocíticas. Recientemente, el anticuerpo monoclonal eculizumab ha aumentado la expectativa de vida de estos pacientes con una mejoría de su calidad de vida(AU)

Paroxysmal nocturnal hemoglobinuria (PNH) is a non malignant and acquired clonal disease of the hematopoietic stem cell. It is a severe and rare disease. It is the only acquired hemolytic disturbance that is caused for an erythrocyte membrane anomaly. It is a result of a somatic clonal mutation of one gene that is located in the short arm of X chromosome called phosphatidyl inositol glycan class A (PIG-A). Regulated complement proteins are identified: the decay accelerated factor (CD55) and the membrane inhibitor or reactive lysis (CD 59); the abnormal blood cells of PNH have deficiency of these two proteins. PNH is classified in: classic PNH, PNH associated with another bone marrow disturbance and PNH sub clinic. Diagnosis is obtained by hematological, biochemical, kinetics and imagenologics studies and serologic special tests. High resolution membrane protein electrophoresis and flow cytometry are the elective tests. Treatments for anemia, thrombotic episodes and infections are important in the management of these patients. Steroids, androgens, human recombinant erythropoietin and granulocytic colony stimulating factor (CSF-G) are the more used pharmacology agents. Recently, the monoclonal antibody eculizumab has increased the life expectation in these patients with a better quality of life(AU)

Hemoglobinuria paroxística nocturna: de Strübing al Eculizumab / Paroxysmal nocturnal hemoglobinuria: from Strübing to Eculizumab

La hemoglobinuria paroxística nocturna (HPN) es un trastorno clonal severo y raro no maligno y adquirido de la célula madre hematopoyética. Es el único trastorno hemolítico adquirido causado por una anomalía de la membrana eritrocitaria como resultado de una mutación somática clonal de un gen, el fosfatidilinositol glucano clase A (PIG-A) situado en el brazo corto del cromosoma X. Se han identificado una serie de proteínas reguladoras del complemento, entre las que se destacan: el factor acelerador de la degradación (CD55) y el factor inhibidor de la lisis reactiva de la membrana (CD 59) deficientes en esta enfermedad. La HPN se clasifica en clásica, asociada a otro trastorno medular y en subclínica. Su diagnóstico se apoya en estudios hematológicos, bioquímicos, pruebas serológicas especiales, estudios eritroferrocinéticos e imagenológicos. La electroforesis de proteínas de membrana de alta resolución y la citometría de flujo multiparamétrica constituyen técnicas de elección para el diagnóstico. El tratamiento de la anemia, de los episodios trombóticos y de las infecciones constituyen los pilares terapéuticos básicos. Dentro de los agentes farmacológicos más utilizados se destacan: los esteroides. los andrógenos, la eritropoyetina recombinante humana y el factor estimulador de colonias granulocíticas. Recientemente, el anticuerpo monoclonal eculizumab ha aumentado la expectativa de vida de estos pacientes con una mejoría de su calidad de vida

Paroxysmal nocturnal hemoglobinuria (PNH) is a non malignant and acquired clonal disease of the hematopoietic stem cell. It is a severe and rare disease. It is the only acquired hemolytic disturbance that is caused for an erythrocyte membrane anomaly. It is a result of a somatic clonal mutation of one gene that is located in the short arm of X chromosome called phosphatidyl inositol glycan class A (PIG-A). Regulated complement proteins are identified: the decay accelerated factor (CD55) and the membrane inhibitor or reactive lysis (CD 59); the abnormal blood cells of PNH have deficiency of these two proteins. PNH is classified in: classic PNH, PNH associated with another bone marrow disturbance and PNH sub clinic. Diagnosis is obtained by hematological, biochemical, kinetics and imagenologics studies and serologic special tests. High resolution membrane protein electrophoresis and flow cytometry are the elective tests. Treatments for anemia, thrombotic episodes and infections are important in the management of these patients. Steroids, androgens, human recombinant erythropoietin and granulocytic colony stimulating factor (CSF-G) are the more used pharmacology agents. Recently, the monoclonal antibody eculizumab has increased the life expectation in these patients with a better quality of life

Frequency of paroxysmal nocturnal hemoglobinuria in patients attended in Belém, Pará, Brazil

BACKGROUND: Paroxysmal nocturnal hemoglobinuria is a hematological disease with complex physiopathology. It is genetically characterized by a somatic mutation in the PIG-A gene (phosphatidylinositol glycan anchor biosynthesis, class A), in which the best known antigens are DAF (decay accelerating factor or CD55) and MIRL (membrane inhibitor of reactive lysis or CD59). OBJECTIVE: To determine the frequency of paroxysmal nocturnal hemoglobinuria in patients attended at the HEMOPA foundation from November 2008 to July 2009. METHOD: Thirty patients, with ages ranging from two to 79 years old and suspected of having paroxysmal nocturnal hemoglobinuria were examined. All patients were immunophenotyped by flow cytometry for the CD5, CD59, CD16 and CD45 antigens. RESULTS: Paroxysmal nocturnal hemoglobinuria was identified in nine of the thirty patients investigated. Another 3 cases had inconclusive results with CD59-negative labeling only for neutrophils. The highest frequency of paroxysmal nocturnal hemoglobinuria patients (7/9) and inconclusive cases (2/3) were between 19 years old and 48 years old, with a median of 28 years. CONCLUSION: These results show the importance of flow cytometry to identify cases in which patients are deficient in only one antigen (CD59).

Frequency of paroxysmal nocturnal hemoglobinuria in patients attended in Belém, Pará, Brazil.

BACKGROUND: Paroxysmal nocturnal hemoglobinuria is a hematological disease with complex physiopathology. It is genetically characterized by a somatic mutation in the PIG-A gene (phosphatidylinositol glycan anchor biosynthesis, class A), in which the best known antigens are DAF (decay accelerating factor or CD55) and MIRL (membrane inhibitor of reactive lysis or CD59). OBJECTIVE: To determine the frequency of paroxysmal nocturnal hemoglobinuria in patients attended at the HEMOPA foundation from November 2008 to July 2009. METHOD: Thirty patients, with ages ranging from two to 79 years old and suspected of having paroxysmal nocturnal hemoglobinuria were examined. All patients were immunophenotyped by flow cytometry for the CD5, CD59, CD16 and CD45 antigens. RESULTS: Paroxysmal nocturnal hemoglobinuria was identified in nine of the thirty patients investigated. Another 3 cases had inconclusive results with CD59-negative labeling only for neutrophils. The highest frequency of paroxysmal nocturnal hemoglobinuria patients (7/9) and inconclusive cases (2/3) were between 19 years old and 48 years old, with a median of 28 years. CONCLUSION: These results show the importance of flow cytometry to identify cases in which patients are deficient in only one antigen (CD59).

Hemoglobinúria paroxística noturna: da fisiopatologia ao tratamento / Paroxysmal nocturnal hemoglobinuria: from physiopathology to treatment

Hemoglobinúria paroxística noturna (HPN) é uma anemia hemolítica crônica adquirida rara, de curso clínico extremamente variável. Apresenta-se frequentemente com infecções recorrentes, neutropenia e trombocitopenia, e surge em associação com outras doenças hematológicas, especialmente com síndromes de falência medular, como anemia aplásica e síndrome mielodisplásica. É considerada ainda um tipo de trombofilia adquirida, apresentando-se com tromboses venosas variadas, com especial predileção por trombose de veias hepáticas e intra-abdominais, sua maior causa de mortalidade. A tríade anemia hemolítica, pancitopenia e trombose faz da HPN uma síndrome clínica única, que deixou de ser encarada como simples anemia hemolítica adquirida para ser considerada um defeito mutacional clonal da célula-tronco hematopoética (CTH). A mutação ocorre no gene da fosfaditilinositolglicana classe-A, e resulta no bloqueio precoce da síntese de âncoras de glicosilfosfaditilinositol (GPI), responsáveis por manter aderidas à membrana plasmática dezenas de proteínas com funções específicas. A falência em sintetizar GPI madura gera redução de todas as proteínas de superfície normalmente ancoradas por ela. Dentre elas estão o CD55 e o CD59, que controlam a ativação da cascata do complemento. Assim, na HPN há aumento da susceptibilidade de eritrócitos ao complemento, gerando hemólise. Revisa-se aqui sua fisiopatologia, curso clínico, os tratamentos disponíveis com ênfase para o transplante de células-tronco hematopoéticas alogênicas e para o eculizumab, um anticorpo monoclonal humanizado que bloqueia a ativação do complemento terminal no nível C5 e previne a formação do complexo de ataque à membrana, a primeira droga a demonstrar eficácia no tratamento da HPN.

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare disorder, an acquired chronic hemolytic anemia, often associated with recurrent nocturnal exacerbations, recurrent infections, neutropenia, thrombocytopenia, and episodes of venous thrombosis. Its clinical course is highly variable. It frequently arises in association with bone marrow failure, particularly aplastic anemia and myelodysplastic syndrome. It is also an acquired thrombophilia, presenting with a variety of venous thrombosis, mainly manifested with intra-abdominal thrombosis, here the major cause of mortality. The triad of hemolytic anemia, pancytopenia, and thrombosis makes a truly unique clinical syndrome of PNH, which was reclassified from a purely acquired hemolytic anemia to a hematopoietic stem cell mutation defect of the phosphatidyl inositol glycanclass-A gene. This mutation results in an early block in the synthesis of glycosylphosphatidylinositol (GPI) anchors, responsible for binding membrane functional proteins. Among these proteins are the complement inhibitors, especially CD55 and CD59, that play a key role in protecting blood cells from complement cascade attack. Therefore, in PNH occurs an increased susceptibility of red cells to complement, and consequently, hemolysis. We here review PNH physiopathology, clinical course, and treatment options, especially eculizumab, a humanized monoclonal antibody that blocks the activation of terminal complement at C5 and prevents formation of the terminal complement complex, the first effective drug therapy for PNH.