Cast Nephropathy and plasmapheresis

Does removal of the light chains with plasmapharesis reduce the severity of cast nephropathy? We know that renal failure is a terrible prognostic factor in multiple myeloma so fixing acute renal failure is important.

Renal failure comes in many different flavors with myeloma:

• Light chain deposition disease
• Heavy chain deposition disease that I have never seen but Steve Rankin had a case as a fellow.
• Amylloidosis
• Hypercalcemia
• Cast nephropathy

Only the last is amenable to plasmapheresis. Whether it works has been the subject of three prospective randomized studies:

1. Zucchelli 1988
2. Johnson 1990
3. Clark  2005 (PDF)

UPDATE

Though not randomized this recent article from KI should be of interest (Thanks Kyste):

Leung et al. Improvement of cast nephropathy with plasma exchange depends on the diagnosis and on reduction of serum free light chains. Kidney Int (2008) vol. 73 (11) pp. 1282-8.

Great cases on call

I'm running the on-call gauntlet.

I was on call Sat and Sun December 6,7

Sat December 13

Sat and Sun December 20,21

Thursday through Sunday December 25-28

four straight week-ends, with Christmas thrown in for the Jew. Ughh.

That said this week-end has had a few great cases:

• IgM Cold-agglutinin hemolytic anemia in need of plasmapheresis.
• Fluconazole induced hyperkalemia
• Urinary obstruction induced electrogenic type 1 RTA (Hyperkalemic variety of type 1 RTA)
• Primary hyperaldosteronism induced hypertensive emergency
  

I'll elaborate on some (all) of these cases in the next few days.

Happy holidays