The immunoregulatory abilities of polymorphonuclear neutrophils in multiple sclerosis.

Ziaber et


M. Mayer
Neurore habilitatio n Unit, Dep artme nt of Rehabilitation, Faculty Hospital, 779 00 Olomouc, Czech Republic Email: michal@tunw.upol.cz EDITOR -In their very inte re sting w ork, Ziaber e t a l. 1 rais ed a que stion conce rning invo lve ment of polymorphonuc lear ne utrop hils (PMNs) in the pathoge nesis of multiple sclerosis (MS). Their re sults provide ne w and, from the point of vie w of re ce nt c onc ep ts, rathe r unusual ins ights into MS pathoge ne sis.
We w e re pleased to re ad this. In our earlie r ex pe riments, w e also found some e vide nc e of abnormal PMN ac tivation in MS. More ove r, these abnormalitie s appeare d to be depe nde nt on the inte rac tion w ith autologous thromboc yte s. We used tw o te st syste ms: the nonadhere nt re sponse of le ukocyte s elic ite d by c alc ium ionophore A23187; and, furthermore , w e inve stigate d the luminol-depe nde nt che miluminisce nce .
Using the ionophore stimulation , w e found that granulocyte s pre inc ubate d w ith autologous thrombocyte s (but not granuloc yte s alone ) had inc re ase d nonadhere nt re sponse in he althy controls. This phenomenon w as le ss ex pre ssed in MS patie nts and abse nt in MS patie nts taking c ortic oste roids. We spe culate d that the se re sults may re flec t a thrombocyte -depe nde nt alte ratio n of adhe sive membrane propertie s during the early phase of nonspec ific PMN activatio n. 2 In the chemiluminisc enc e studie s, 3 the additio n of autologous thrombocyte s marke dly depre ssed both the spontane ous and the zymosanstimulate d granuloc yte che miluminis ce nce in MS patie nts and in patie nts w ith some othe r ne urologic al diseases. In healthy contro ls, this w as ex pre sse d le ss pronounc edly. These finding s might indic ate an activation of thrombocyte supp re ssive or scave nger function in MS and some other ne urological disease s.
Although the PMNs see m not to be dire c tly involve d in the de mye linatio n proce ss w ithin the central ne rvous syste m, the y might play an important part in the c omplex inte rac tions during vascular and hematogenic proce sse s assoc iate d w ith immunoac tivation in MS. In our opinio n, this level of MS immunopathogene sis dese rve s gre ate r and more inte nsive atte ntion.
EDITOR -I agre e w ith Dr Maye r that PMN c ells, espec ially in the blood of MS patie nts, are not only 'the sile nt observe rs'. In my study, I have de scribe d the enhanc e d ex trac e llular marke rs ex pre ssion on PMNs that might suggest priming of PMNs of the peripheral blood. In the course of clinic ally active MS, the role of PMNs in MS has not yet bee n show n. Our study doe s not show it either, thus there is still an unsolve d problem as to w hether the se ce lls play an important role in the c ourse of MS and how the y are activate d.
Dr Maye r sugge sts, on the basis of his study, that the change d re ac tivity of PMNs in the c ours e of MS is due to thromboc yte -depe nde nt alte ratio n of the membrane propertie s during the early phas e of nonspe cific PMNs activatio n. This canno t be ex cluded. It is w orthw hile to ex pre ss that, in both studie s, Dr Maye r draw s conclusions base d on in vitro studie s. Furthe rmore , PMNs w ere is olate d from patie nts during diffe re nt stage s of MS activ ity. In MS patie nts w ithout cortic oste roid tre atme nt, rath er he te rogene ous re sults w ere obtaine d, w hich appe ars to re flec t the fluctuatio n in the dise as e activ ity. In my opinio n, the study w ould have be en more inte re sting if the study groups had c ons iste d of MS patie nts in the same stage of MS activ ity.