goodpasture 's syndrome is characterized by anti - glomerular basement membrane ( gbm ) antibodies   and rapidly progressive glomerulonephritis . the standard therapy of goodpasture 's syndrome consists of immunosuppressive therapy with corticosteroids and cyclophosphamide in combination with plasma exchange , which dramatically improves outcomes . patients with goodpasture 's syndrome , who are refractory or intolerant to the standard therapy , are still known to have a poor prognosis in terms of mortality and renal survival . agents that specifically target activated b lymphocytes might provide new treatment of this antibody - mediated autoimmune disorder . rituximab is a chimeric monoclonal antibody that targets the b lymphocyte antigen cd20 . in one patient with goodpasture 's syndrome , it was possible to discontinue cyclophosphamide and prednisolone after the fourth cycle of rituximab , but it is unclear whether plasmapheresis was continued after administration of rituximab or not . we describe two cases of goodpasture 's syndrome , which were treated with rituximab as rescue therapy , when renal function did not recover with standard treatment . haemoglobin was 9.4 g / dl , creatinine 2.3 mg / dl , anti - gbm antibodies 57 u / l ( normal < 10 ) , while c - anca , p - anca , ana and ds - dna antibodies were negative . a renal biopsy was performed , and light microscopy revealed 10 glomeruli , with cellular and partly fibrinoid crescents in all glomeruli . the patient was transferred to our hospital 3 weeks later , when her serum creatinine had risen to 527 mol / l and urinary protein excretion was 9.17 g/24 h. physical examination was normal except massive oedema of the legs . weight was 71 kg , height 181 cm , blood pressure 120/80 mmhg and pulse rate 66/min . haemodialysis and daily plasmapheresis ( each 4000 ml replaced by 30 g / l albumin ) were started 3 days after admission . additionally , the patient was treated with oral cyclophosphamide 200 mg / day adjusted to leukocyte counts . because of the lack of clinical response to this therapy , a single dose of rituximab 1000 mg was administered intravenously on day 9 after admission . four weeks after administration of rituximab , cd19/20 cell expression monitored by flow cytometry was negative . in week 4 , plasmapheresis was performed again but renal function did not improve . haemodialysis had to be resumed in week 5 , persumably because treatment was started in a very late stage of the disease . in week 6 , the patient had a generalized seizure and had to be admitted to the intensive care unit . mrt of the brain showed enhanced subcortical and pontal signal intensity ( figure 1 ) . examination of the spinal liquor showed no cells and virological examination by pcr disclosed no polyoma virus replication in the liquor . a second mrt of the brain was performed in week 10 revealing improvement in the subcortical and pontal signal intensities . cerebral t2-weighted mri showing a triangular lesion of the corpus callosum with signs of leukoencephalopathy ( arrow ) . a 20-year - old man who had experienced fatigue for over 2 months was admitted to our hospital with serum creatinine of 3.4 mg / dl and macrohaematuria . physical examination was normal , weight 88 kg , height 178 cm , heart rate 80 beats / min and blood pressure 124/75 mmhg . the results of laboratory tests were as follows : haemoglobin 7.8 g / dl , creatinine 370 mol / l , anti - gbm antibodies 94 ku / l ( normal < 10 ) , while c - anca , p - anca , ana and ds - dna antibodies were normal . urine examination showed many red cells with acanthocytes and proteinuria of 1.89 g / g creatinine . a renal biopsy was performed , and light microscopy showed 8 glomeruli with cellular partly fibrinoid crescents in all of them . treatment was started with 1000 mg prednisolone intravenously for 3 days and oral cyclophosphamide 200 mg / day . prednisolone 100 mg / day was given orally for three weeks and then slowly tapered . because of rising creatinine ( 654 mol / l ) , rituximab 1000 mg was administered once intravenously after 2 weeks ( figure 2 ) . since renal function deteriorated , accompanied by oliguria , plasmapheresis was resumed three times a week for 7 weeks . on this therapy , anti - gbm antibodies could no longer be detected after week 12 ( figure 2 ) . it was finally possible to discharge the patient from hospital without dialysis after 3 months . levels of serum creatinine and anti - gbm antibodies before and during treatment with cyclophosphamide , prednisolone , plasmapheresis and rituximab ( arrow ) . in this report , we describe the effects of a single dose of rituximab in two patients with refractory goodpasture 's syndrome . serum creatinine continued to increase after rituximab administration in both cases , but only decreased after plasmapheresis was resumed in case 2 . it might be speculated that the single rituximab dose ( 1  1000 mg ) that was given in our two cases was not enough . but in both patients , cd 19/20 cell count was negative 4 weeks after administration of rituximab . another case is reported where recurrent anti - gbm disease in a kidney transplant did not respond to rituximab therapy . a severe side effect of rituximab was seen in our first patient caused by jc polyoma virus - negative leukoencephalopathy . recently , cases of jc polyoma virus - positive leukoencephalopathy induced by chemotherapy or rituximab have been described . in our case ,
we describe the effects of rituximab in two patients with refractory goodpasture 's syndrome . 
 after one single 1000 mg dose administration , rituximab did not appear to improve renal function in either of our cases . 
 polyoma virus - negative leukoencephalopathy , a probable toxic side effect of rituximab , was seen in our first patient .