The immunoregulatory abilities of polymorphonuclear neutrophils in multiple sclerosis.

EDITOR – In their very inte resting work, Ziaber e t a l. rais ed a question conce rning invo lvement of polymorphonuclear ne utrop hils (PMNs) in the pathogenesis of multiple sclerosis (MS). Their results provide new and, from the point of view of recent concepts, rathe r unusual ins ights into MS pathogenesis. We were pleased to read this. In our earlie r ex pe riments, we also found some evidence of abnormal PMN ac tivation in MS. Moreover, these abnormalitie s appeared to be dependent on the inte rac tion w ith autologous thrombocytes. We used tw o te st systems: the nonadherent re sponse of leukocytes elic ited by calc ium ionophore A23187; and, furthermore , we inve stigated the luminol-depende nt chemiluminiscence . Using the ionophore stimulation , w e found that granulocytes pre inc ubate d w ith autologous thrombocytes (but not granuloc ytes alone) had inc reased nonadherent response in healthy controls . This phenomenon was le ss ex pressed in MS patients and absent in MS patie nts taking cortic oste roids. We speculated that the se results may re flec t a thrombocyte-depende nt alte ration of adhe sive membrane propertie s during the early phase of nonspec ific PMN activatio n. In the chemiluminiscenc e studie s, the additio n of autologous thrombocyte s marke dly depressed both the spontane ous and the zymosanstimulate d granuloc yte chemiluminis cence in MS patients and in patients w ith some othe r ne urologic al diseases . In healthy contro ls, this w as ex pre ssed le ss pronouncedly. These finding s might indic ate an activation of thrombocyte suppre ssive or scave nger function in MS and some other ne urological disease s. Although the PMNs seem not to be dire c tly involve d in the demye linatio n proce ss w ithin the central nervous system, they might play an important part in the complex inte rac tions during vascular and hematogenic proce sse s assoc iated w ith immunoac tivation in MS. In our opinion, this leve l of MS immunopathogene sis dese rve s greate r and more inte nsive attention.