Blood harmane (1-methyl-9H-pyrido3,4-bindole) concentration in dystonia cases vs. controls.
Harmane (1-methyl-9H-pyrido3,4-bindole) (HA) is a potent neurotoxin that has been linked to two neurological diseases, essential tremor and Parkinsons disease. Blood harmane concentrations HA are elevated in patients with both diseases. An important question is whether HA is specifically linked with these diseases or alternatively, is a non-specific marker of neurological illness. We assessed whether blood HA was elevated in patients with a third neurological disease, dystonia, comparing them to controls. Blood HA was quantified by high performance liquid chromatography. Subjects comprised 104 dystonia cases and 107 controls. Mean log blood HA in dystonia cases was similar to that of controls (0.41±0.51g(-10)ml vs. 0.38±0.61g(-10)ml, t0.42, p0.68). In unadjusted and adjusted logistic regression analyses, log blood HA was not associated with the outcome (diagnosis of dystonia vs. control) odds ratio (OR)unadjusted1.11, 95% confidence interval (CI)0.69-1.79, p0.68 ORadjusted1.07, 95% CI0.58-1.97, p0.84. In contrast to the elevated blood HA that has been reported in patients with essential tremor and Parkinsons disease, our data demonstrate that blood HA was similar in patients with dystonia and controls. These findings provide the first support for the notion that an elevated blood HA is not a broad feature of neurological disease, and may be a specific feature of certain tremor disorders.