The B-cell compartment in the thymus of myasthenia gravis and control patients

34

Ihe B-eel] compartment

in the thymus of Myasthenia Gravis and

control patients. CHRISIENSSON B., Biberfeld P., Natell G., Dept. of Pathology, Karolinska Hospital and Hyasthenia Gravis Center, South Hospital, Stockholm, S~eder,.

H y p e r p l a s t i c and n e o p l a s t i c thymic changes are frequent in t lyasthenia G r a v i s . 14ost f r e q u e n t l y f o l l i c u l a r in many aspects the B - c e i l

h y p e r p l a s i a i s seen, resembling

follicles

i n lymph nodes. Using a panel

o f monoclona] a n t i b o d i e s the d i s t r i b u t i o n

o f B- and I - c e l l

antigens

has been s y s t e m a t i c a l l y i n v e s t i g a t e d and r e l a t e d to the d i s t r i b u t i o n o f stromal c e l l s such as e p i t h e l i a l

and r e t i c u l a r

c e i l s of the thymus.

Using B - c e l l s p e c i f i c Habs v a r i a b l e numbers o f p o s i t i v e c e i l s were found, most]> l o c a t e d i n the medulla.

The frequency i s however in

many cases h i g h e r than i n d i c a t e d by Ig s t a i n i n g , of B - c e l l

follicles

ll:lbs to l ' o ] l t c u l a r sections,

was u s u a l l y r e v e a l e d a f t e r dendrttic

cells

fhe increased number

immunostainino w i t h

{DRC) as compared to H & E - s t a i n e d

lJs~ng mouse monocJonal antiidiotypic antibodies against

human ac~'tylcholinc receptor

(ACHR., antibodies the localization oF

cells producing anti AOHR autoantibodies was attempted and correlated to the B-celt -and f-o][icular dendritic cell distribution in thymus from rn)~sthenJc and control patients.

Molecular Genotyplng of the Multlple Sclerosis Patients

T-Cell

Receptor

Beta Chain in Families of

Ciu]]a TA, Rob~nmon MA, DooIitt]e T, Kindt TJ, and Rauser £L Boston, MA In experimental qystems, heritab]o variatinns within the T-ce]] receptor (TCR) beta (/~) chain ~ene c,~mp]ex are associated with an increased ~uscept~b[lity to autoJmmunity. In mu]tip]e sclerosi~ (MS) patients, assiKnment of T C R ~ chain hap]otypes is possible uslnK prrbes to both the constant (C) and variable (V) ~ene seKment~ (in this ca~e, VB.I) of the TCR-/~ chain, and Southern Blot/restriction fragment lenFth polymorphism (RFLP) analysi~ of genr~mic DNA. C~ RFI.P is present fol]ow~n~ di~estlon with RFlTI, and V~ RFLP is pre~ent u~in~ H~>d_TTI or B amHI