A new communicable disease, severe acute respiratory syndrome (SARS), has emerged in the 21st century in 31 countries and regions. There have been 56 SARS cases in our city. To salvage a 28 year old pregnant woman with SARS we treated her with plasma from a SARS volunteer who was convalescing and one month post recovery. This played a key role in her therapy. We obtained 500 ml of plasma using the MCS+ apheresis machine.
Subject. A woman running a high fever and coughing was admitted to hospital on March 28. The illness developed quickly and the diagnosis appeared to be severe acute respiratory syndrome with failure of respiratory function seven days later. Her respiratory rate increased to over 40 per minute and the oxygen content of her blood was very low. It was considered that a miscarriage would give rise to DIC if the symptoms could not be controlled. Steroids, anti-viral medications and a respirator were ineffective.
Method. It was decided to treat her with convalescent plasma. Considering the ill health of the volunteer and without a compatible disposable set, we decided to use the MCS+ and the 995E/LDPLP protocol to obtain a single plasma collection. The target plasma volume was adjusted to 500 ml, the transfer pump was not mounted and the relative part of the tubing on the dual pump manifold was clamped. When the collection procedure went into the DWELL step, centrifugation was stopped by pressing the STOP key and by returning the blood in the bowl to the donor without plateletpheresis. This was repeated three times.
Effect. The 500 ml of plasma was divided into two bags. Immediately after the plasma was confirmed to be safe according to our criteria for blood donation, 250 ml of plasma was transfused into the patient. Five hours later her oxygen saturation and pulse improved. The second infusion of another 250 ml of plasma was given 12 h later. Impressive events occurred. The patient came off the respirator and X-ray showed that the lung shadows had distinctly faded compared to the picture seen 36 h previously.
Suggestion. This clinical outcome may well suggest an important reason, given the current emergency situation, for the use of single-donor plasma from SARS convalescent patients, which potentially contains neutralizing immunoglobulin (Ig)G or M. The infusion of 500 ml of plasma corresponds to about 5 g of Ig, based on a mean content of 10 g/l of plasma. No side effects were observed. Based on this result and on another similar report [1], our recommendation is to establish a therapeutic chain of passive immunotherapy in SARS patients. The recipient treated with the plasma in SARS convalescence, on recovering from SARS, might then become the next plasma donor. This plasmapheresis technique can provide a link between collection and transfusion in a therapeutic chain.
References
- 1.Wong VWS, Dai D, Wu AKI, Sung JJY. Treatment of severe acute respiratory syndrome with convalescent plasma. Hong Kong Med J, April 2003. Expedited publication [PubMed]
