Table 4.

Incidence and treatment of relapse (N = 5)

Patient	Duration of PEX at first presentation	Time to relapsea after first presentation	Treatment of relapse	Outcome
2	PEX × 32 exchanges	88 days	PEX	Creatinine 100 μmol/l eGFR >60 ml/min per 1.73 m2 No further relapse
10	PEX × 30 exchanges	Multiple relapses	PEXb	Creatinine 83 μmol/l eGFR >60 ml/min per 1.73 m2 Relapse-free since 2012
16	PEX × 8 mo	1254 days	Eculizumab	Creatinine 86 μmol/l eGFR 53 ml/min per 1.73 m2 No further relapse
18	PEX × 5 exchanges	43 days	PEX	Creatinine 89 μmol/l eGFR >60 l/min per 1.73 m2 No further relapse
21	PEX × 15 exchanges	266 days	PEX + rituximab	Creatinine 87 μmol/l eGFR >60 ml/min per 1.73 m2 No further relapse

eGFR, estimated glomerular filtration rate; PEX, plasma exchange.

The 2 patients treated with PEX at first presentation who recovered renal function and did not experience relapse were patient 17 (PEX twice weekly for 2 months) and patient 23 (PEX × 6 exchanges); both patients have an eGFR of >60 ml/min per 1.73 m².

eGFR by Schwartz formula for patients younger than 18 years of age at last follow-up (patients 10, 16, and 18) and by an abbreviated Modification of Diet in Renal Disease equation for patients older than 18 years of age at the last follow up (patients 2 and 21).

^aRelapse defined as recurrence >1 month after presentation and >15 days after disease remission.

^bPatient 10 experienced multiple relapses and was PEX dependent between 2004 and 2011 (PEX every 4 weeks), but has not experienced further relapse since PEX was withdrawn in 2012.