Study of hypothalamic pituitary adrenal axis in patients of membranous nephropathy receiving modified Ponticelli regimen

Pulse methyl prednisolone followed by oral prednisolone and abrupt switch to chlorambucil/cyclophosphamide (Ponticelli/modified Ponticelli regimen) is used in patients with idiopathic membranous nephropathy. This therapy where steroids are stopped abruptly is unphysiologic and expected to have hypothalamic pituitary adrenal (HPA) axis suppression; however, this has not been evaluated. A total of 13 consecutive adult patients with idiopathic membranous nephropathy who had completed modified Ponticelli regimen were studied. The regimen included administration of pulse methylprednisolone 1 g for 3 days followed by oral prednisolone 0.5 mg/kg/day for 27 days followed by oral cyclophosphamide at a dose of 2 mg/kg/day for the next month. This was repeated for three courses. Patients who had received corticosteroids prior to therapy were excluded. The HPA axis was evaluated after 1 month of completing the last course of steroid therapy. The evaluation was done using a low-dose adrenocorticotropic hormone stimulation test. A single intravenous bolus dose of synacthen (1 μg) was given at 9.00 am and the serum cortisol levels were estimated by radioimmunoassay at 0, 30, and 60 min. A peak cortisol level of 550 nmol/L or higher was considered as normal. Mean baseline cortisol levels was 662.3 ± 294.6 nmol/L and peak cortisol level was 767 ± 304.4 nmol/L. A total of 6 patients (46.2%) had low basal cortisol levels, only 3 (23%) had both basal and peak cortisol levels < 550 nmol/L suggestive of HPA axis suppression. To conclude, 23% of patients had suppression of HPA axis after modified Ponticelli regimen.