You are asked to see a 68 year old woman on the haematology ward of a teaching hospital. From the notes you learn that she has multiple myeloma with IgG lambda paraprotein. Serum creatinine at the time of diagnosis was 155μmol/l and there was 13g/24h of proteinuria. Initial treatment was with bortezomib (Velcade), doxorubicin and dexamethasone, but this was discontinued after 2 cycles due to 'disease progression'. You are unable to find an exact description of this 'progression' in her notes, but her creatinine had risen to 312μmol/l during this period.
As a result, therapy was switched to lenalidomide and dexamethasone. She has been maintained on such therapy for 6 weeks during which time her creatinine fallen to 189μmol/l.
She has now been admitted following 1 week of lassitude and her creatinine is 427μmol/l, with an albumin of 35g/l. Dipstick testing shows 4+ protein/no blood with a urinary protein excretion of 4.5g/24h. She has been self administering low-molecular weight heparin and epo at home and attending for a monthly bisphosphonate infusion. Other medications are omeprazole and amlodipine.
Examination shows a cushingoid woman with no rash or fever and a BP of 148/83. There is a trace of oedema but nothing else to find. Her Hb is 8.9g/dl and her platelet count 123.
- What further information would you like: either as new investigations or from the course of the illness so far?
- Would you suggest a kidney biopsy in this case and why?