Growth hormone and insulin growth factor-I levels in plasma and cerebrospinal fluid of patients with multiple sclerosis.

Multiple sclerosis (MS) has several clinically different forms. Whereas the illness progresses slowly in most of the patients, 10% have an aggressively progressive course with fatal outcome without signs of remyelination capability. The process of remyelination depends on numerous interactive factors, including the presence of various growth factors, the most important of which in the adult is insulin growth factor-I (IGF-I). On the other hand, the most powerful postnatal regulator of IGF-I is growth hormone (GH), which also acts as a neuroprotective and an antiapoptotic agent, and has direct influence on myelination. Levels of these growth factors have never been examined in the cerebrospinal fluid (CSF) of patients with MS. The levels of IGF-I and GH were measured in serum and CSF of 46 MS patients and compared with those of 49 patients with no evidence of demyelinating disease. The only positive finding was a deficiency of GH in the CSF of MS patients. The possible implications of those findings in the etiopathogenesis of MS will be discussed.