Page 349 - The Vasculitides, Volume 1: General Considerations and Systemic Vasculitis

Giant Cell Arteritis 323

sizes and apparent selection bias [86, 147]. Pulsed intravenous methylprednisolone was
advocated in patients with GCA and visual disturbances [11, 12], however one observational
study [128] and another RCT [148] failed to demonstrate improved efficacy in preventing
visual loss compared to high-dose oral therapy. Moreover, intravenous pulsed
methylprednisolone, which demonstrated no significant long term glucocorticoid sparing
effects in the treatment of simple forms of GCA, was reserved for complicated forms of
GCA.

Figure 5. Proportion of positive TAB biopsy specimens as a function of weeks on treatment with
glucocorticoids. An estimate of the mean length of treatment at two time points was made from each
study report listed below and plotted on the chart wherein the thickness of the lines represented the
number of subjects reported in the study. References: Study a: (136); Study b: (137); Study c: (87);
Study d: (138); Study e: (8). Abbreviation: TAB, temporal artery biopsy.

The concern for glucocorticoid resistance in patients with GCA has its origin in the
ophthalmology community where visual loss in GCA is more prevalent [128]. One small
RCT [149] that administered three consecutive days of one gram of intravenous pulsed
methylprednisolone induction, followed by oral glucocorticoids found higher rates of
remission, less relapses, and more rapid tapering compared to patients treated with oral high-
dose glucocorticoid s.

The apparent corticosteroid-sparing benefit of pulsed intravenous methylprednisolone
[149] may not have been clinically significant since the criteria for disease relapses included
instances of raised acute phase responses without clinical flares; moreover there were no
differences in glucocorticoid -related side effects [129]. The glucocorticoid dose can be
gradually tapered in the first month after the resolution of reversible clinical symptoms and
the levels of acute phase reactants falls by 50% [11, 12]. Although other tapering regimens
have been employed [122, 142], the available evidence [90, 142, 146, 150, 151] suggests that
treatment should be continued for at least two years, with most patients weaned off of
medication by four to five years. A minority of them may need continued low-dose
glucocorticoids [85, 121]. Among several GCA treatment trials conducted between 1988 and
2003 [90, 121-123, 142, 145, 146], the median duration of treatment of GCA ranged from

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