A blockage monoclonal antibody protocol as an alternative strategy to avoid anti-CD38 interference in immunohematological testing.

BACKGROUND: As CD38 is expressed on red blood cells (RBCs), the plasma of patients on daratumumab (DARA) reacts with the panel cells of pretransfusion tests, masking underlying alloantibodies. The treatment of RBCs with dithiothreitol (DTT) is the most disseminated method to overcome DARA effect on immunohematological tests, but it hampers the identification of potentially harmful antibodies. Our goal was to validate a new strategy, the blockage monoclonal antibody protocol (BMAP), to mitigate the DARA interference on RBCs using anti-CD38 and antihuman globulin. METHODS: Samples of patients receiving DARA were included in the study. Sera were tested using both DTT- and BMAP-treated RBCs, which comprised three steps: 1) titration of monoclonal anti-CD38, 2) treatment of RBCs obtained from donors with anti-CD38, and 3) blockage of anti-CD38-adsorbed RBCs with antihuman globulin. RESULTS: Twenty patients were included in the study. Donor RBCs were treated with anti-CD38 and successfully blocked with antihuman globulin. In 19 patients, DARA-mediated agglutination was eliminated using both DTT- and BMAP-treated RBCs. In one patient, agglutination persisted when tested against the BMAP-treated RBCs, and alloantibodies were identified. Patient samples were mixed with commercial anti-D, -C, -e, -K, -Jka, -Kpb and tested against antigen-positive BMAP-treated RBCs, resulting in detection of these antibodies. CONCLUSION: This study validated a new strategy to minimize the interference of DARA on immunohematological tests. The protocol preserves the integrity of RBC antigens, permitting the detection of antibodies from all blood group systems. The BMAP has potential use in other situations where specific antibodies may interfere with pretransfusion screening.

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

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.

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.

Successful hematopoietic stem cell mobilization with vinorelbine and filgrastim in germ cell tumor.

Germ cell tumor (GCT) is the most frequent cancer in young men and is highly curable. Almost 80 % of patients with the disease in an advanced stage achieve a reliable response to cisplatin combination chemotherapy. For relapsing or refractory disease, autologous hematopoietic stem cell transplantation (HSCT) is an effective therapy. The two most used mobilization strategies for HSC collection are filgrastim alone or filgrastim after chemotherapy (chemomobilization). HSC collection with filgrastim mobilization can be difficult, especially in highly treated patients. While the addition of chemotherapy improves mobilization and reduces the number of apheresis sessions, it can increase morbidity rate as well. We describe a case of a 45-year-old male with classical seminoma who was submitted to orchiectomy. Two months after, he presented progression of the tumor. He received four cycles of cisplatin, etoposide and bleomycin, with residual retroperitoneal mass and cervical lymphadenopathy. Further, he was submitted to three more cycles of cisplatin, ifosfamide and paclitaxel. Thereupon, he showed partial response. At that moment, autologous HSC transplantation was considered. In the first mobilization, filgrastim alone was used without success in harvesting. The second mobilization consisted of vinorelbine at day 1 (35 mg/m2) and filgrastim (16 µg/kg) started at day 5. The peak of CD34+ cells in peripheral blood was 32.6 × 106 cells/L on day 8, with 4.73 × 106 cells/kg CD34+ collected on days 8 and 9. The benefits of this scheme include: (a) outpatient administration, (b) fewer doses of filgrastim, (c) minimal risk of febrile neutropenia and (d) reliable prediction of collection day. For these reasons, we conclude that vinorelbine chemomobilization is a great option for GCT, particularly in patients with high risk of mobilization failure. Furthermore, it requires less resource usage, hospitalizations and transfusions than conventional chemomobilization.