Tellez-Zenteno et al identified factors associated with favorable and unfavorable prognosis in patients with myasthenia gravis who underwent thymectomy. This can help identify patients who may benefit from more aggressive therapy. The authors are from Mexico City.
Poor prognostic factors:
(1) age > 60 years of age
(2) interval between diagnosis and thymectomy > 4 years (tendency at > 3 years duration, but did not reach statistical significance)
(3) Osserman Stage I (ocular muscles only)
(4) thymoma or thymic atrophy on pathologic examination of the thymus
(5) use of steroids before thymectomy
(6) high doses of pyridostigmine prior to thymectomy
In addition, patients with a poor prognosis required plasmapheresis after thymectomy.
Prognostic Factor |
Odds Ratio for Poor Prognosis |
95% Confidence Interval |
p value |
age > 60 years |
4.6 |
1.11 – 20.32 |
0.01 |
interval before surgery > 4 years |
2.53 |
0.83 – 7.7 |
0.06 |
Osserman Stage I |
4.97 |
1.02 – 28.63 |
0.01 |
thymoma |
3.51 |
0.45 – 31.5 |
0.15 |
thymic atropy |
2.19 |
0.93 – 5.16 |
0.04 |
use of steroids |
2.26 |
0.99 – 5.18 |
0.03 |
pyridostigmine > 240 mg |
2.79 |
1.12 – 7.13 |
0.01 |
pyridostigmine > 360 mg |
3.33 |
1.23 – 9.15 |
0.007 |
where:
• Some of the prognostic factors have a p value > 0.01.
NOTE: A table comparing factors identified in previous studies is given on page 175.
Purpose: To identify prognostic factors in a patient with myasthenia gravis treated by thymectomy according to Tellez-Zenteno et al.
Specialty: Immunology/Rheumatology
Objective: severity, prognosis, stage, response to therapy, surgery
ICD-10: G70,