[Treatment of paroxysmal nocturnal hemoglobinuria with antilymphocyte globulin]

To evaluate the effectiveness of antilymphocyte globulin therapy (ALG) in patients with paroxysmal nocturnal hemoglobinuria (PNH).

Prospective, non-controlled trial.

Hematology Service, Hospital de Especialidades, Centro Médico Nacional Siglo XXI, IMSS, Mexico City.

Six patients were included. The median age was 37.5 years and the male/female ratio was 1:1. All the patients had clinical disease consistent with PNH (hemolytic anemia with some degree of transient or persistent pancytopenia) and also erythrocytes with enhanced sensitivity to complement mediated lysis in vitro, as documented by either the Ham test or the sucrose lysis assay. The criterion for severity was the existence of continuous hemolysis in all and transfusion requirements of two or more packed red cells per month in four cases. Prior to ALG therapy, androgens and/or steroids had been given to five patients with no improvement.

A single batch of ALG was used during the trial (E 0034, Lymphoglobulin Mérieux, Lyon, France). Patients received an infusion of 10 mg/kg per day in a 20 hours lapse during four consecutive days. Also 500 mg/day of methylprednisolone were started simultaneously with the ALG; it was given for seven days and was gradually tapered off and stopped on day 30.

The increases in hemoglobin, granulocytes and/or platelets as well as decreases in red cell transfusion requirements were used to evaluate the results of therapy.

Two patients suffered anaphylaxis after the first administration of ALG and were withdrawn from the study. Two of the four remaining patients responded, one response was total and the other minimal. The responses were transient, and no response was seen in the follow-up of 11-14 months.

ALG therapy for PNH in the doses and time periods used by us had no beneficial effect in patients with a severe form of PNH.