Abstract

INTRODUCTION:

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease of unknown origin which has been linked to chronic infections due to intracellular microorganisms.

AIMS:

The purpose of this study was to identify species of Mycoplasma in blood samples from patients with clinically defined ALS by means of the polymerase chain reaction (PCR) method in comparison to healthy control subjects.

PATIENTS AND METHODS:

We conducted a case-control study involving 75 participants, 20 of whom were patients with clinically defined ALS and 55 healthy controls. Venous blood samples were taken and processed in the Neuroimmunology Laboratory, where they were submitted to the PCR test for Mycoplasma sp.

RESULTS:

The patients with ALS were between 35 and 82 years old (mean: 52.5); the ages of the healthy control subjects ranged from 35 to 60 years (mean: 44.1). After performing the PCR for Mycoplasma sp. the following results were obtained: among the patients with ALS, 10 were found to be positive (50%) and 10 were negative (50%), whereas in the control subjects we found six positives (10.91%) and 49 negatives (89.09%); these results were statistically significant (p = 0.001). On calculating the estimated risk, an odds ratio of 8167 (CI 95%: 2.4-27.6) was obtained. This indicates that the risk of suffering from ALS, if the PCR test for Mycoplasma sp. is positive, is 8:1.

CONCLUSIONS:

There is a strong link between suffering from a chronic infection due to Mycoplasma and developing ALS. Intracellular pathogenic agents such as Mycoplasma can play a role in the genesis of neurodegenerative diseases.