Abstract
Editor:
Episodes of icodextrin-associated sterile peritonitis in patients maintained on chronic peritoneal dialysis (PD) have recently been described (1-9). The reaction seems to be batch related since some PD patients have been rechallenged with another batch of icodextrin without further symptoms of peritonitis (1-3,7,8).
The syndrome is caused by contamination of icodextrin with a bacteria-derived peptidoglycan, a nonendotoxin pyrogen capable of provoking the inflammatory response in peritoneum. Peptidoglycan is a major constituent of the cell wall of gram-positive organisms (10). A commercially available silkworm larvae plasma (SLP) reagent test has been used for peptidoglycan measurement; the detection limit of the assay is 7.4 ng/mL (11). In most batches of Extraneal (Baxter Healthcare, Castlebar, Ireland), the proteoglycan is undetectable [P(–)]; batches of Extraneal with a detectable content of peptidoglycan [P(+)] were recalled by Baxter Healthcare in May 2002 (Divino J, Baxter Healthcare; personal communication).
At our center, 7 patients exposed to P(+) batches of Extraneal presented with culture-negative peritonitis (prevalence 20%). Two patients had their PD catheter removed and were converted to hemodialysis due to “nonresolving culture negative peritonitis.” In another 2 patients, the symptoms progressively subsided despite maintenance of the icodextrin prescription. Three patients were rechallenged with P(–) batches of Extraneal, resulting in prompt recurrence of cloudy fluid.
It is feasible to think that the prompt recurrence of symptoms when rechallenged with P(–) Extraneal in some but not all patients is caused by allergy/hyper-reactivity in sensitized patients previously exposed to the SLP-reactive peptidoglycan. The adverse reactions may be attributable to undetectable trace amounts of the SLP-reactive peptidoglycan or cross-reactivity with other antigens in the bags. The concept of an allergic reaction in sensitized patients could also explain the apparently individual variability in susceptibility to re-exposure.
Our observations indicate that patients may become hypersensitive to the peptidoglycan contaminant in Extraneal.