Index case supporting the need to identify BSA-specific IgE levels
in commercial plasma.
A colt of unknown gestational age was born to a malnourished dam with
little to no udder development nor colostrum/milk production. The owner
administered a commercial powdered bovine/multi-species colostrum
supplement3 orally within the first 2 hours of life.
Subsequently, the colt was examined and evaluated for transfer of
passive immunity status. An IgG test4 was performed at
12 hours of age, which revealed complete failure of transfer of passive
immunity (0 mg/dL IgG). The owners elected to continue supplementing the
foal on the farm with the powdered colostrum product despite
recommendations that it was unlikely to result in adequate transfer of
passive immunity. At 24 hours of age a recheck IgG
test4 measured an IgG level of 400 mg/dL IgG,
consistent with ongoing partial failure of transfer of passive immunity.
Once these results were provided, the owners elected to have the
attending clinician perform a plasma transfusion with 1L (22 ml/kg) of
commercial high immunoglobulin equine plasma.1 Plasma
was thawed according to the label instructions while an intravenous
catheter was placed into the left jugular vein. Initial physical
examination performed was within normal limits. Plasma administration
was initiated at a very slow rate initially of 0.05 ml/kg/minute (1
drop/2-3 seconds). Temperature, heart and respiratory rates were
measured at 3-5 minute intervals. Signs of colic, dyspnea and urticaria
were monitored for continuously. With no evidence of an adverse
reaction, the administration rate was slowly increased to 0.15
ml/kg/minute (1 drop/second) over the next 5-10 minutes. At 15 minutes
the rate was increased to approximately 0.38 ml/kg/minute (2-3
drops/second), at this point the foal quickly began to show colic signs.
The plasma infusion was stopped immediately. Crackles were auscultated
in all lung fields and pink-tinged foamy nasal discharge became evident
bilaterally suggestive of pulmonary edema. The foal became apneic after
one minute. Intravenous epinephrine5 (0.02 mg/kg) was
administered along with furosemide6 (1 mg/kg) and
dexamethasone7 (0.15 mg/kg). The foal did not respond
to emergency medications or attempts at field cardiopulmonary
resuscitation and died within 3 minutes following discontinuation of the
plasma transfusion.
Based on the history and response of this foal to plasma transfusion, it
was suspected that this foal suffered from BSA-associated
hypersensitivity. This outcome was consistent with previous anecdotal
reports of foals consuming powdered colostrum followed by IV commercial
plasma infusion, which has been reported to result in fatal reactions.
The remaining commercial plasma administered to this foal was saved at
-80˚ C for further analysis.