Contributions
Type: Publication Only
Background
Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, genetically acquired, life-threatening disease. We report 24 cases of PNH diagnosed and followed by flow cytometry (FC).
Aims
To evaluate the size of PNH clones and their clinical impact
Methods
The PNH clone was required in the event of bone marrow aplasia with or without hemolysis, of regenerative haemolytic anemia with negative direct Coombs test, in case of Myélodysplastic syndrome, in case of unexplained cytopenia and in thrombosis.
The research of the clone by FC is carried out by analysis of the following monoclonal antibodies: Flear, CD59, CD14 with gating on the CD45, CD64 and on Glycophorin A ; the clone was required on the red cells, neutrophil graulocytes (NG) and monocytes. We judged that the patients (pts) has a HPN clone when the deficit is > 5% on at least two markers highlighted on two different lines. PNH clone was diagnosed among 151 pts since August 2009. A monitoring by CMF is ensured in the event of absence of deficit or a very moderate deficit or concerning only one line.
Results
On 151 analyzed cases, absence of HPN clone in 127 cases (84,2%); ln 24 cases (15,8%), a deficit ≥ two markers in two lines or more was present.
They are 10 women and 14 men; sex ratio = 1,4, median age = 41 years (21-58).
PNH clone was found in bone marrow aplasia: 15/67 cases (22, 4%), hemolytic anemia with negative direct coombs: 2 /28 case (7,1%), other hemolysis : 2/11 cases (18%), thrombosis: 2 /21 (9,5%), bone marrow aplasia in pregnancy: 1/3 cases (33%), myelodysplastic syndrome : 02/14 cases (14.3%) and cytopénia: 0/6 cases.
Types of HPN: type II: 2 cases (8,4%), type III: 16 (66%), mixed type: 6 cases (25%). The median rate of deficit of the CD59 on red cells = 31.7% (5-72), of the CD59 on neutrophil granulocytes = 58,7% (7-99) and of Flear carried out in 11 cases = 61.42% (6-98) and the deficit on the monocytes was required in 8 cases, the median rate of the deficit of CD14 = 77.7% (22-97) and of Flear (4 cases) = 72,2% (19,4-92,1).
In monitoring: appearance of the PNH clone in 1 case, increase in the size of clone in 4 cases, initially lower than 2%, and in a case the clone has doubled of size from 54% to 98% after 6 months and the patient developed a wide thrombosis. In 13 cases, a moderate deficit of a marker was noted on only one line.
Summary
In our study HPN clone was noted in 14% of the cases of MDS which joined the literature.
In the group where moderate deficit was observed, biological signs of hemolysis were absent; the indication of a follow-up of the size of HPN clone is then necessary and must include an assessment of hemolysis repeated with evaluation of the LDH; that is checked in our study since in 04 cases of increase size of the clone, a thrombosis occurred in one case.. B. Höchsmann showed after follow-up of 155 cases a significant increase of the clone in 28% of cases.
The application of FC, enabled us to make the diagnosis of PNH. Moreover it determined the phenotypic profile of PNH clones in our area and specified their size; it is also very useful for the follow-up of the patients. It remains a key examination in the diagnosis of the PNH and in some cases it will be necessary to repeat research of the clone after a first negative analysis in particular in the event of bone marrow aplasia and of hemolysis associated, and also in the event of small clone to follow its evolution.
Keyword(s): Flow cytometry, PNH
Session topic: Publication Only
Type: Publication Only
Background
Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, genetically acquired, life-threatening disease. We report 24 cases of PNH diagnosed and followed by flow cytometry (FC).
Aims
To evaluate the size of PNH clones and their clinical impact
Methods
The PNH clone was required in the event of bone marrow aplasia with or without hemolysis, of regenerative haemolytic anemia with negative direct Coombs test, in case of Myélodysplastic syndrome, in case of unexplained cytopenia and in thrombosis.
The research of the clone by FC is carried out by analysis of the following monoclonal antibodies: Flear, CD59, CD14 with gating on the CD45, CD64 and on Glycophorin A ; the clone was required on the red cells, neutrophil graulocytes (NG) and monocytes. We judged that the patients (pts) has a HPN clone when the deficit is > 5% on at least two markers highlighted on two different lines. PNH clone was diagnosed among 151 pts since August 2009. A monitoring by CMF is ensured in the event of absence of deficit or a very moderate deficit or concerning only one line.
Results
On 151 analyzed cases, absence of HPN clone in 127 cases (84,2%); ln 24 cases (15,8%), a deficit ≥ two markers in two lines or more was present.
They are 10 women and 14 men; sex ratio = 1,4, median age = 41 years (21-58).
PNH clone was found in bone marrow aplasia: 15/67 cases (22, 4%), hemolytic anemia with negative direct coombs: 2 /28 case (7,1%), other hemolysis : 2/11 cases (18%), thrombosis: 2 /21 (9,5%), bone marrow aplasia in pregnancy: 1/3 cases (33%), myelodysplastic syndrome : 02/14 cases (14.3%) and cytopénia: 0/6 cases.
Types of HPN: type II: 2 cases (8,4%), type III: 16 (66%), mixed type: 6 cases (25%). The median rate of deficit of the CD59 on red cells = 31.7% (5-72), of the CD59 on neutrophil granulocytes = 58,7% (7-99) and of Flear carried out in 11 cases = 61.42% (6-98) and the deficit on the monocytes was required in 8 cases, the median rate of the deficit of CD14 = 77.7% (22-97) and of Flear (4 cases) = 72,2% (19,4-92,1).
In monitoring: appearance of the PNH clone in 1 case, increase in the size of clone in 4 cases, initially lower than 2%, and in a case the clone has doubled of size from 54% to 98% after 6 months and the patient developed a wide thrombosis. In 13 cases, a moderate deficit of a marker was noted on only one line.
Summary
In our study HPN clone was noted in 14% of the cases of MDS which joined the literature.
In the group where moderate deficit was observed, biological signs of hemolysis were absent; the indication of a follow-up of the size of HPN clone is then necessary and must include an assessment of hemolysis repeated with evaluation of the LDH; that is checked in our study since in 04 cases of increase size of the clone, a thrombosis occurred in one case.. B. Höchsmann showed after follow-up of 155 cases a significant increase of the clone in 28% of cases.
The application of FC, enabled us to make the diagnosis of PNH. Moreover it determined the phenotypic profile of PNH clones in our area and specified their size; it is also very useful for the follow-up of the patients. It remains a key examination in the diagnosis of the PNH and in some cases it will be necessary to repeat research of the clone after a first negative analysis in particular in the event of bone marrow aplasia and of hemolysis associated, and also in the event of small clone to follow its evolution.
Keyword(s): Flow cytometry, PNH
Session topic: Publication Only