Multiple Sclerosis, 1 October 2003, vol. 9, no. 5, pp. 467-471(5)
Grimaldi L.M.E.; Pincherle A.; Martinelli-Boneschi F.; Filippi M.; Patti F.; Reggio A.; Franciotta D.; Allegra L.; Comi G.; Blasi F.
 Department of Neurosciences, AUSL 2 Caltanissetta, Via G. Cusmano 3, 93100 Caltanissetta, Italy & Neuroimmunology Unit, IRCCS Ospedale San Raffaele, Via Olgettina 58, 20100, Milan, Italy  Neuroimmunology Unit, IRCCS Ospedale San Raffaele, Via Olgettina 58, 20100, Milan, Italy  Neurological Department, IRCCS Ospedale San Raffaele, Via Olgettina 58, 20100, Milan, Italy  Neuroimaging Research Unit, IRCCS Ospedale San Raffaele, Via Olgettina 58, 20100, Milan, Italy  Neurological Department, University of Catania, Viale A. Doria 6, 95100, Catania, Italy  IRCCS Neurological Institute 'C. Mondino Foundation', Via Palestro 3, 27100, Pavia, Italy  Institute of Respiratory Diseases, University of Milano, IRCCS Ospedale Maggiore di Milano, Via F. Sforza 35, 20100, Milan, Italy
We amplified sequences of the Chlamydia pneumoniae (CP) major-outer membrane protein in the cerebrospinal fluid (CSF) from 23 of 107 (21.5%) relapsing-remitting or secondary progressive multiple sclerosis (MS) patients and two of 77 (2.6%) patients with other neurological diseases (OND) (P=0.00022).
CP+ patients showed magnetic resonance imaging (MRI) evidence of more active disease (P=0.02) compared to CP– MS patients and tended to have an anticipation of age at disease onset (32.3±12 versus 28.5±10 years; P= ns) causing a longer disease duration (7.5±5 versus 4.4±4 years; P=0.016) at the time of clinical evaluation.
These findings, although indirectly, suggest that CP infection of the central nervous system (CNS) might affect disease course in a subgroup of MS patients.