NEW YORK (Reuters Health) – Intravenous immunoglobulin (IVIG) offers advantages over plasma exchange (PLEX) for many patients with myasthenia gravis, according to a report online in the November 8th Annals of Neurology.

Lacking a rigorous evidence base, clinicians must choose myasthenia gravis treatments largely on the basis of expert recommendations and personal experience.

Dr. Amer Alshekhlee from St. Louis University, St. Louis, Missouri and colleagues used hospital discharge information from the Healthcare Cost and Utilization Project-Nationwide Inpatient Sample (HCUP-NIS) administrative database to compare clinical and economic outcomes among 1606 patients hospitalized with myasthenia gravis.

In-hospital mortality among patients admitted with myasthenia gravis was similar for those treated with IVIG (0.58%) and PLEX (0.41%), but for patients with myasthenia gravis crisis, mortality was significantly higher among those who received PLEX (5.67%) than among those who received IVIG (0.59%).

Complication rates did not differ between treatments for patients admitted with myasthenia gravis, but among patients with myasthenia gravis crisis, complications occurred at significantly higher rates after PLEX (30.06%) than after IVIG treatment (14.79%).

Regardless of admitting diagnosis, hospital length of stay was significantly longer for patients treated with PLEX than for those treated with IVIG. Moreover, hospital charges were higher in patients treated with PLEX in both the myasthenia gravis and myasthenia gravis crisis groups.

After adjustment for all significant covariates, however, mortality rates and complication rates did not differ significantly between PLEX and IVIG, but treatment with IVIG continued to be associated with shorter length of stay and lower hospital charge.

Prognosis appeared to depend “only upon the presence of acute respiratory failure, major cardiac complications, and acute renal failure,” investigators say. “Older age and acute respiratory failure led to a higher incidence of complications, after adjusting for other significant independent predictors.”

“Some patients, especially the elderly, those with complex comorbid disease, and those in acute respiratory failure, may be better served by IVIG therapy than PLEX,” the researchers conclude.

“The analysis offers insight into real-world outcomes of treatments for a rare disease,” they add. “However, the results should be interpreted with caution as the dataset lacks information on the clinical characteristics for patients in the study.”

Reference:

Comparative analysis of therapeutic options used for myasthenia gravis

Ann Neurol 8 November 2010.