Detection of paroxysmal nocturnal haemoglobinuria clones in cases of deep vein thrombosis in a tertiary care centre, western Rajasthan

Background & objectives: Paroxysmal nocturnal haemoglobinuria is a rare acquired disease characterized by bone marrow failure, intravascular haemolysis and thrombophilia. Thrombosis is the deadliest complication of paroxysmal nocturnal haemoglobinuria (PNH). The present study was conducted to study the prevalence of PNH in cases of deep vein thrombosis (DVT) which was previously undocumented from western Rajasthan. Methods: In the present cross-sectional study, 61 adult patients with DVT were tested using flow cytometry to detect PNH clones. Blood samples were processed using fluorescein-labelled proaerolysin, CD14, CD24, CD33 and CD45 panels for granulocytes and monocytes and CD59 and CD235a panel for red blood cells. Results: Three cases (4.92%) having large clones on monocytes as well as granulocytes, which fulfilled the diagnostic criteria of PNH were detected. Further, three cases (4.92%) showed small clones on both granulocytes and monocytes. Nine (15%) cases showed small clones only on granulocytes, and 11 (18%) cases showed small clones only on monocytes. Interpretation & conclusions: The results of the present study suggest that a higher proportion of patients had PNH in western Rajasthan compared to previously reported studies from elsewhere. It is suggested that PNH testing should be added to the procoagulant work-up panel in institutions of this region where it is not routinely done. This provides an otherwise missed opportunity to diagnose this disorder. Eculizumab may be employed, which is effective in reducing thrombophilic events in cases of PNH

Childhood aplastic anaemia with paroxysmal nocturnal haemoglobinuria clones: A retrospective single-centre study in South Africa

Background: Paroxysmal nocturnal haemoglobinuria (PNH) clones in children are rare but commonly associated with aplastic anaemia (AA) and myelodysplasia.Objective: This study aimed to determine the prevalence of PNH clones in paediatric patients with idiopathic AA, identify differences in clinical and laboratory features and outcomes, and determine the impact of clone size on clinical presentation.Methods: Patients with confirmed idiopathic AA who were tested for PNH between September 2013 and January 2018 at the Inkosi Albert Luthuli Central Hospital, Durban, KwaZulu-Natal, South Africa, were included. PNH clones were detected in neutrophils and monocytes by flow cytometry using fluorescent aerolysin, CD24, CD66b and CD14. Results: Twenty-nine children with AA were identified and 11 were excluded. Ten patients (10/18, 55.6%) had PNH clones ranging from 0.11% to 24%. Compared to the PNH-negative group, these children were older (median: 10 years vs 4 years, p= 0.02) and had significantly lower total white cell counts (median 1.7 × 109/L vs 3.2 × 109/L; p= 0.04). There was no difference in median absolute neutrophil count or haemoglobin concentration. Four patients in each group received immunosuppressive therapy (IST). At six months, all four patients with PNH clones had responded, compared to one in the PNH-negative group. Conclusion: More than half of children with AA had a PNH clone. The size of the clone did not impact clinical severity; however, IST use may positively impact prognosis. We recommend early initiation of IST in patients with AA to avoid delays associated with human leukocyte antigen typing.

Renal involvement in paroxysmal nocturnal haemoglobinuria: a brief review of the literature

SUMMARY INTRODUCTION: Paroxysmal Nocturnal Haemoglobinuria (PNH) is an acquired genetic disorder characterized by complement-mediated haemolysis, thrombosis and variable cytopenias. Renal involvement may occur and causes significant morbidity to these patients. OBJECTIVE: To review the literature about pathophysiology and provide recommendations on diagnosis and management of renal involvement in PNH. METHODS: Online research in the Medline database with compilation of the most relevant 26 studies found. RESULTS: PNH may present with acute kidney injury caused by massive haemolysis, which is usually very severe. In the chronic setting, PNH may develop insidious decline in renal function caused by tubular deposits of hemosiderin, renal micro-infarcts and interstitial fibrosis. Although hematopoietic stem cell transplantation remains the only curative treatment for PNH, the drug Eculizumab, a humanized anti-C5 monoclonal antibody is capable of improving renal function, among other outcomes, by inhibiting C5 cleavage with the subsequent inhibition of the terminal complement pathway which would ultimately give rise to the assembly of the membrane attack complex. CONCLUSION: There is a lack of information in literature regarding renal involvement in PNH, albeit it is possible to state that the pathophysiological mechanisms of acute and chronic impairment differ. Despite not being a curative therapy, Eculizumab is able to ease kidney lesions in these patients.

RESUMO INTRODUÇÃO: A hemoglobinúria paroxística noturna (HPN) é uma doença genética adquirida, caracterizada por hemólise mediada pelo sistema complemento, eventos trombóticos e citopenias variáveis. Envolvimento renal pode ocorrer, contribuindo com morbidade significativa nesses pacientes. OBJETIVO: Realização de revisão de literatura sobre o envolvimento renal na HPN. MÉTODOS: Pesquisa on-line na base de dados Medline, com compilação e análise dos 26 estudos encontrados de maior relevância. RESULTADOS: A HPN pode se apresentar com insuficiência renal aguda induzida por hemólise maciça, que geralmente tem apresentação grave. Em quadros crônicos, declínio insidioso da função renal pode ocorrer por depósitos tubulares de hemossiderina, microinfartos renais e fibrose intersticial. Apesar de o transplante de células-tronco hematopoiéticas permanecer como a única terapia curativa para a HPN, a droga Eculizumab é capaz de melhorar a função renal, entre outros desfechos, por meio da inibição de C5 e a subsequente ativação da cascata do complemento, que culminaria com a formação do complexo de ataque à membrana. CONCLUSÃO: Há poucas informações na literatura no que concerne ao envolvimento renal na HPN, apesar de ser possível estabelecer que os mecanismos fisiopatológicos das lesões agudas e crônicas são distintos. Apesar de não ser uma terapia curativa, Eculizumab é capaz de amenizar o comprometimento renal nesses pacientes.

Advance in research of thrombosis in paroxysmal nocturnal hemoglobinuria / 基础医学与临床

Paroxysmal nocturnal haemoglobinuria ( PNH) is a clonal hematopoietic stem cell disease characterized by intravascular hemolytic anemia , pancytopenia and thrombosis .Although PNH is an non-malignant disease , its complications have very negative impacts on patient's quality of life .The most common serious complication is thrombosis formation .