Autoimmune hemolytic anemia in patients with SCID after T cell-depleted BM and PBSC transplantation.

We report a high incidence (19.5%) of autoimmune hemolytic anemia (AIHA) in 41 patients with SCID who underwent a T cell-depleted haploidentical transplant. Other than infections, AIHA was the most common post-transplant complication in this patient cohort. Clinical characteristics and treatment of eight patients who developed AIHA at a median of 8 months after the first T cell-depleted transplant are presented. All patients had warm-reacting autoantibodies, and two of eight had concurrent cold and warm autoantibodies. Clinical course was most severe in two patients who had cold and warm autoantibodies. Five patients received specific therapy for AIHA. Successful taper off immunosuppressive therapy for AIHA coincided with T cell reconstitution. Delayed reconstitution of T cell immunity, due to T cell depletion, immunosuppressive conditioning and CsA, as well as paucity of regulatory T cells, are the likely explanations for the occurrence of AIHA in our patient cohort. Screening of the population at risk may prevent morbidity and mortality from AIHA.

Two cases of "hrB-like" autoantibodies appearing as alloantibodies.

Two cases are described in which autoantibodies mimicked alloantibodies. The direct antiglobulin test (DAT) on the red cells (RBCs) from both patients was negative when routine manual hexadimethrine bromide (Polybrene) and enzyme-linked antiglobulin techniques were used. The RBCs also did not react on direct bromelin and direct Polybrene tests. However, an "hrB-like" antibody was eluted from the RBCs of both patients. The sera from these patients reacted with all e+ hrB+ RBCs but not with e+ hrB-, e-, or their own RBCs. The antibody in the serum of one patient was not adsorbed by R2R2 RBCs. Serologic tests initially suggested (by direct testing and adsorption studies) that the serum antibodies were alloantibodies rather than autoantibodies. RBCs taken from one patient, 8 months after her sample was first referred to our laboratory, reacted with a serum sample from her first admission. An RBC sample taken from the other patient, initially typed e+ and hrB- but 1 month later typed e+ and hrB+ by using the same anti-hrB sera, was used to test the earlier samples.

A new test useful in identifying red cells with a (delta-alpha) hybrid sialoglycoprotein.

St(a+) and Dantu+ red cells (RBCs), treated with 0.1 percent ficin solutions, reacted strongly with Vicia graminea lectin (anti-NVg). No other RBC sample tested gave these results. This test (ficin-pretreated RBCs tested with anti-NVg [FT-NVg]) was used to screen the RBCs of 300 Oriental and 100 black donors. Three percent of the Oriental donor samples tested were FT-NVg+, whereas no FT-NVg + RBCs were found in the black donor samples tested. The FT-NVg test is easy to perform and gives selective reactions with antigens associated with (delta-alpha) hybrid sialoglycoproteins, such as Sta and Dantu. This test can be used for mass screening of RBCs in a search for St(a+) or Dantu+ RBCs. Another application of the FT-NVg test would be to screen RBCs suspected of having a low-incidence antigen before using scarce anti-Sta and -Dantu reagents.