Abstract 4670

BACKGROUND:

Acute hemolytic reactions (AHR) associated with administration of Rho (D) Immune Globulin (RhIG; WinRho® SDF, Cangene Corporation, Winnipeg, Canada) have been infrequently reported during the previous 16 years. AHR were defined as any case reported with signs of hemolysis (hemoglobin decrease, haptoglobin decrease, LDH increase, elevation of bilirubin, etc.) occurring within hours to a number of days after RhIG administration irrespective of the degree of change from baseline. Intravascular hemolysis (IVH) was defined as a specific type of AHR in which plasma or urinary hemoglobin were positive. The reporting rate of AHR (including IVH) among RhIG-treated patients was previously estimated as 1/946 doses (0.11%), while the estimated reporting rate of IVH was 1/3,271 doses (0.03%).1 Reports surrounding the clinical monitoring of such patients have led to the analysis of AHR post-marketing data.

AIMS/PURPOSE:

Identify the onset of AHR/IVH symptoms relative to RhIG and determine if prior exposure to RhIG mitigates the risk of such events.

METHODS:

Retrospective evaluation of AHR (AEs reported with signs of hemolysis; including IVH) from the Cangene post-marketing surveillance database.

RESULTS:
Table 1.

Onset of AHR Symptoms (January 1995 to May 14, 2011)

Onset of Symptoms (hr)Definite IVH† (%)Other AHR (%)Total AHR* (%)
0–2 32 27 28 
2–4 8 13 12 
4–6 5 2 3 
6–8 5 3 3 
0–8 50 45 46 
8–12 2 1 1 
12–24 13 10 11 
24–48 7 8 8 
48–72 2 12 10 
>72 8 11 10 
Unk 18 13 10 
Total n=60 n=146 n=206 
Onset of Symptoms (hr)Definite IVH† (%)Other AHR (%)Total AHR* (%)
0–2 32 27 28 
2–4 8 13 12 
4–6 5 2 3 
6–8 5 3 3 
0–8 50 45 46 
8–12 2 1 1 
12–24 13 10 11 
24–48 7 8 8 
48–72 2 12 10 
>72 8 11 10 
Unk 18 13 10 
Total n=60 n=146 n=206 
†

Demonstrated plasma hemoglobinemia and/or hemoglobinuria

*

All serious cases receiving RhIG for the ITP indication, with or without information on receiving their first dose or having previous treatment with RhIG.

View Large
Table 2

Effect of Prior Exposure on Risk of AHR: Prior Use of RhIG (January 1995 to May 14, 2011)

IVHAHR*
RhIG Treatment Naïve (%) 31 (84%) 94 (80%) 
RhIG Treatment Experienced (%) 6 (16%) 24 (20%) 
Total Cases† n=37 n=118 
IVHAHR*
RhIG Treatment Naïve (%) 31 (84%) 94 (80%) 
RhIG Treatment Experienced (%) 6 (16%) 24 (20%) 
Total Cases† n=37 n=118 
*

Including IVH

†

Consists of serious cases of ITP patients receiving RhIG with history of receiving/not receiving prior dosage of RhIG. Patients for whom no information was provided surrounding prior RhIG were excluded from the analysis.

View Large
CONCLUSION:

Of the ITP patients who developed IVH, 40% reported an onset of symptoms within 4 hours of RhIG infusion; an additional 10% reported symptoms within 8 hours. The symptom onset was unidentified in 18% of IVH cases. In addition, previous uneventful administration of RhIG did not preclude the possibility of an occurrence of IVH and its complications following subsequent administration of RhIG; however, the majority (approx 84%) of reports of IVH were among RhIG naïve patients.

Disclosures:

Muller:Cangene: Employment. Little:Cangene: Employment. Hess:Cangene: Employment. Sinclair:Cangene: Employment.

Topics:
immunoglobulins, inosine triphosphate, purpura, thrombocytopenic, idiopathic, symptom onset, rho(d) immune globulin, hemoglobin, abnormal involuntary movement scale, alberta infant motor scales, bilirubin, haptoglobins

RamachandranP. Potential identification of high-risk populations for acute hemolytic reactions following Rho(D) IGIV. Poster #III-464 presented at the 2010 ASH Annual meeting (Orlando); December 2010.

Author notes

*

Asterisk with author names denotes non-ASH members.

© 2011 by The American Society of Hematology
2011
Sign in via your Institution