MASTCELLS IN DUCHENNE MUSCOLAR DISTROPHY

Balboni G.C. °°°, Vannelli G.B.°, Repice F.°, Scorzoso A.000

, Marconi G.°° 0

Department of Human Anatomy and Histology 00

Clinic of Neurological deseases Faculty of Medicine, University of Florence 000

Institute of Physical Education, Florence ITALY

INTRODUCTION

Aim of this research is to evaluate the change in the number of mastocytes (MC) and their characteristics in the muscolar tissue of DMD in comparison with different types of myopathies and normal controls. The research wants also to complete the data obtained by our group in previous studies concerning the submicroscopic pattern of the muscolar fibres and the behaviour of MC and satellite cells in DMD (Bucciolini M.G. et. al., 1983 ; Repice F et al., 1989).

As well known, MC seem to play an important role in the pathogenesis of distrophin

deficient myopathies. According to Gorospe et al. (1994) MC accumulation and degranulation

might be responsable not only for the process of fibrosis that goes on together with the

muscular alterations, but also in grouped muscular necrosis occuring in distrophin deficient

myophaties.

METHODS

Muscular biopsies of four groups of subjects were utilized : 1) 12 control subjects, previously

informed and consenting; 2) 18 subjects suffering from DMD aged 2 to 7 years; 3) 25

subjects affected with limb girdle muscolar distrophy (LGMD); 4) 17 subjects suffering from

neurogenic muscular disorders.

All cases were studied from a clinical point of view in the Clinic of Neurological

deseases. The demonstration and statistical evaluation of MC was done in the Dept. of human

Anatomy and Histology. The histological specimens were stained with routine methods (H.E.,

Toluidine blue). In addition the Avidin FITC thecnique was applied. The average number of

MC was evaluated in each case and in each group. The standard deviation and the comparison

of averages was performed.

RESULTS

1) in DMD cases some changes in the morfological characteristics and localisation of

MC were observed. In a large number these celles were degranulating and generally located in

the endomisium around the muscolar fibres. A concentration of degranulating cells was

observed also in the sites where the degeneration of the muscolar tissue was more prominent.

In the other miopathies less evident changes were detected.

so T

40 ..

30 .

20 ..

10 ..

control Duchenne LGMD N.D

Averages of MC in the groups considered

240

2) In DMD the MC number is higher in a very significant statistical way than in

controls and it is higher also in comparison with the other groups considered.

However in these groups too the MC number is statistically increased.

3) In each case of DMD the MC number is always high, but it presents some variations

due to the age of patients and the stage of the desease. A more evident variability was

observed in the limb girdle patients.

DISCUSSION

This research confirms the importance of MC in the pathogenesis of the muscolar

distrophies considered. The greatest increse in the number of MC was detected in DMD. The

distrophin deficiency seem to be an important factor in favouring the role of MC both in

fibrosis of the interstitium and muscolar fibres necrosis. In any case, fibrosis is a common event

in muscolar distrophies and the fact that the limbgirdle sindrome is essentially heterogeneous in

aetiology and non obligatory distrophin deficency dependent, may esplain the less increase and

great variability of number of MC in these cases.

REFERENCES

Bucciolini M.G., Vannelli G., Scardicci E., Calandi C., Adami-Lanni C. : I mastociti nel

muscolo scheletrico umano normale e di soggetti affetti da DMD

Arch. Ital. Anat. Embr. 88, 137 - 147, 1983

Gorospe J.R., Tharp M.A., Hinckley J., Kornegay J.N., Hoffman E.P. : A role for mastcelles in

the progression of DMD ?

J. Neural. Sciences 122, 44 - 56, 1994

Repice F., Vannelli G.B., Balboni G.C. : Le cellule satelliti nel muscolo normale e distrofico

Arch. Ital. Anat. Embr. 94, 393 - 403, 1989