Effectiveness of therapeutic plasma exchange in the 1996 Lanarkshire Escherichia coli 0157 : H7 outbreak

Background The haemolytic uraemic syndrome (HUS)/thrombotic thrombocytopeni c purpura (TTP) during an Escherichia coli 0157 outbreak occurred in 1996 i n central Scotland. Adults who develop HUS/TTP induced by E coli 0157 tend to be elderly and have a historical mortality rate of almost 90% when treat ed conservatively, Therefore the decision was made to treat adults who deve loped HUS/TTP during this outbreak with therapeutic plasma exchange (TPE). We report our outcome with this controversial treatment. largest number of adult cases of uraemic syndrome (HUS)/thrombotic Methods A case definition for HUS/TTP was developed at the beginning of the outbreak. All cases meeting this definition were considered for TPE. Infor mation on demographics, clinical features, treatment and outcome of patient s was obtained by retrospective case note review. Findings 22 adults developed HUS/TTP. They had a mean age of 71 years. 16 c ases received TPE. Six cases had contraindications to TPE or died before th e procedure could be done. Ten of the 22 (45%) adults with HUS/TTP died. Fi ve of the 16 (31%) TPE treated cases died, four of eight aged over 70 years compared with one of eight aged less than 70 years. Premorbid illness, neu rological features, treatment with ciprofloxacin or prostacyclin, and the l aboratory severity of HUS/TTP were not associated with death; the number of cases, however, was too small to allow statistical conclusion. Interpretation The mortality rate is high in adults who develop HUS/TTP ind uced by E coli 0157. TPE appears to be a promising treatment that was well tolerated in our elderly patients. A national register of adult cases of HU S/TTP induced by E coli 0157 should be established.