Immunogenetic heterogeneity and associated autoimmune disorders in myasthenia gravis: a population-based survey in the province of Ferrara, northern Italy.
BACKGROUND
The well-established relationship between myasthenia gravis (MG) and HLA antigens varies among different ethnic groups. In Caucasians B8 and/or DR3 alleles have been found associated with young MG women without thymoma and with high titres of acetylcholine-receptor antibody (AChR Ab). An increased frequency of haplotype HLA-A3, B7 and/or DR2 has been observed in older MG patients with low AChR Ab levels. So far, there is no convincing evidence for an association between a specific haplotype HLA and ocular MG or MG with thymoma. MG subjects often show other concurrent autoimmune disorders suggesting a more general inherited predisposition to autoimmunity. We performed a community-based study to verify the HLA-A, B, C, DR and DQ profile on ethnically homogeneous MG patients and with the aim to estimate the frequency of concurrent autoimmune diseases and to compare HLA phenotypes to autoimmune status in different MG patients groups.


METHODS
Forty-seven patients, living in the province of Ferrara, were followed-up in our neurologic department and typed for HLA Antigens. In addition a set of immunological laboratory tests was performed.


RESULTS
We found a trend towards an increased B8 and DR3 frequencies in total affected population; an association between B8 allele and early onset of generalized MG sustained by thymic hyperplasia. The DR3 allele is statistically associated with the presence of additional autoimmune disorders.


CONCLUSIONS
Our data support the hypothesis of a genetically-based heterogeneity of the disease and show an increased prevalence of associate autoimmune conditions in MG patients.
Tola
M R
MR
Institute of Neurology Clinic, University of Ferrara, Ferrara Hospital, Italy.
Caniatti
L M
LM
Casetta
I
I
Granieri
E
E
Conighi
C
C
Quatrale
R
R
Monetti
V C
VC
Paolino
E
E
Govoni
V
V
Pascarella
R
R
D000328:Adult; D000368:Aged; D000483:Alleles; D001323:Autoantibodies / Q000235:genetics / Q000276:immunology; D001327:Autoimmune Diseases / Q000453:epidemiology / Q000235:genetics* / Q000276:immunology; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D005787:Gene Frequency / Q000235:genetics; D018740:Genetic Heterogeneity; D005828:Genetics, Population; D006680:HLA Antigens / Q000235:genetics* / Q000276:immunology; D015795:HLA-B8 Antigen / Q000235:genetics / Q000276:immunology; D015803:HLA-DR3 Antigen / Q000235:genetics / Q000276:immunology; D006801:Humans; D015994:Incidence; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000453:epidemiology / Q000235:genetics* / Q000276:immunology; D010641:Phenotype; D011159:Population Surveillance; D011950:Receptors, Cholinergic / Q000235:genetics / Q000276:immunology; D013945:Thymoma / Q000453:epidemiology / Q000235:genetics / Q000276:immunology; D013953:Thymus Neoplasms / Q000453:epidemiology / Q000235:genetics / Q000276:immunology
D001323:Autoantibodies; D006680:HLA Antigens; D015795:HLA-B8 Antigen; D015803:HLA-DR3 Antigen; D011950:Receptors, Cholinergic