The aim of this work is to study the changes of key assays useful for the understanding of anemia mechanism before and after red packed cells transfusion: iron status, vitamin assays, hemolysis markers.

The aim of this work is to study the changes of key assays useful for the understanding of anemia mechanism before and after red packed cells transfusion: iron status, vitamin assays, hemolysis markers.

The patient selection criteria are:

• age > or = 18 years
• No history of transfusion > or = 2 years
• Anemia (any etiology known or assumed)
• Decision of red packed cells transfusion for the current episode
• Transfusion performed at BEAUJON Hospital
• Agreement of patient for the study

Number of subjects required: 100 patients

Study duration and duration of participation for each patient:

• duration of the study: 1 year
• for each patient the participation to the study began at baseline after the decision of transfusion and stopped at the second sample ie at least 72 hours after the transfusion of red blood cells.

The maximum contribution for one patient is 5 days.

Methodology: It is a prospective non interventional monocentric (BEAUJON Hospital) study. Two blood tests will be performed; one before transfusion and the other from 48 to 72 hours after red packed cells transfusion.

The following parameters will be measured before and after red packed cells transfusion:

Complete blood count (CBC) with reticulocyte count; complete iron status (ferritin, serum iron, transferrin, transferrin saturation), soluble transferrin receptor; serum and intraerythrocytic folate levels, vitamin B12; lactate dehydrogenase (LDH), bilirubin (total and free), haptoglobin, orosomucoid, direct coombs test; creatinine; CRP.

The aim of this work is to study the changes of key assays useful for the understanding of anemia mechanism before and after red packed cells transfusion: iron status, vitamin assays, hemolysis markers.

INCLUSION CRITERIA:

• Age > or = 18 years
• No history of transfusion > or = 2 years
• Anemia (any etiology known or assumed)
• Decision of red packed cells transfusion for the current episode
• Transfusion performed at BEAUJON Hospital
• Agreement of patient for the study

EXCLUSION CRITERIA:

• Patient who received between the 2 samples, a treatment which can modify the parameters evaluated (iron, vitamin)

Anemic patient with decision of red packed cells transfusion for the current episode.