Lactic dehydrogenase isoenzymes in cerebrospinal fluid of children with Guillain-Barré syndrome.

BACKGROUND Increased levels of lactic dehydrogenase (LDH) in the cerebrospinal fluid (CSF) have been reported in association with several intracranial pathologies. No studies have been performed on patients with Guillain-Barré syndrome (GBS). AIMS To study LDH isoenzymes in CSF of children with GBS. METHODS CSF samples collected from nine patients with GBS were analysed for total LDH isoenzymes activity, and compared to samples from 15 patients with normal results. RESULTS Mean total LDH activity was 33.33 (6.63) U/l. All patients had significantly increased LDH-3 isoenzyme compared to controls. LDH-3 was the predominant fraction, accounting for more than 50% of total LDH activity and present in more than twice the percentage of LDH-1 or LDH-2. By contrast, in the control group, there were high percentages of mainly LDH-1 and LDH-2. CONCLUSIONS GBS is apparently associated with a distinct LDH isoenzyme pattern in the CSF. More studies are needed to confirm the rise in LDH-3, as serial CSF analyses are unavailable, and to determine the optimum time of analysis when this finding first becomes detectable.