Glomerulonephritis: the ACR Lupus Nephritis Guidelines

I suggest that you read the American College of Rheumatology Guidelines for Screening, Treatment, and Management of Lupus Nephritis published in Arthritis Care & Research (Volume 64, Issue 6, pages 797–808, June 2012). 

The guidelines on the whole are well reasoned. Of course, it goes without saying that with all of the authors being rheumatologists the symbolism of a rheum guideline about a kidney disease is bothersome, but what to do? Lets accept for a moment that since the larger “Task Force Panel” did include nephrologists and that they spoke up for us. That said, I had several concerns I will address in coming days, but the definition of lupus nephritis (LN) caught my eye:

“ For the purpose of these recommendations, LN is defined as clinical and laboratory manifestations that meet ACR criteria (persistent proteinuria >0.5 gm per day or greater than 3+ by dipstick, and/or cellular casts including red blood cells [RBCs], hemoglobin, granular, tubular, or mixed) [(12)]. A review of the ACR criteria has recommended that a spot urine protein/creatinine ratio of >0.5 can be substituted for the 24-hour protein measurement, and “active urinary sediment” (>5 RBCs/high-power field [hpf], >5 white blood cells [WBCs]/hpf in the absence of infection, or cellular casts limited to RBC or WBC casts) can be substituted for cellular casts [(1)]. An additional, perhaps optimal, criterion is a renal biopsy sample demonstrating immune complex–mediated glomerulonephritis compatible with LN [(1)]. Finally, for the purpose of implementing these recommendations, the Core Executive Panel agreed that a diagnosis of LN should also be considered valid if based on the opinion of a rheumatologist or nephrologist.”

So here is my beef with the statement above:

 “the Core Executive Panel agreed that a diagnosis of LN should also be considered valid if based on the opinion of a rheumatologist or nephrologist.” 

Of course, rheumatologists can make the diagnosis of lupus nephritis just as we nephrologists can make the diagnosis of rheumatoid arthritis in some of our patients. But once we make the diagnosis we do send the patient to our rheumatology colleagues for the prevailing diagnosis and for biologic therapy. This doesn’t seem to happen when it comes to LN. There have been several occasions in my experience when the prevailing diagnosis of LN is made by the rheumatologist and the patient begun on immunosuppressive therapy without nephrology input. It is only when the patient runs into trouble with worsening renal function or is refractory to therapy that we are asked to get involved. 

Besides my concerns about who makes the prevailing diagnosis of LN I took issue with the statement: “An additional, perhaps optimal [underline added], criterion is a renal biopsy sample demonstrating immune complex–mediated glomerulonephritis compatible with LN [(1)]”. Later in the guidelines the authors do state “The Task Force Panel recommended that all patients with clinical evidence of active LN, previously untreated, undergo renal biopsy (unless strongly contraindicated) so that glomerular disease can be classified by current ISN/RPS classification (level C evidence)”

Still, the ACR guidelines label the need for a kidney biopsy as level C evidence. Are they serious? 

The wording of the statement is all wrong as well. I suggest that the words: “perhaps an essential”  as more appropriate about the need for a kidney biopsy. Indeed, I believe that the renal biopsy is essential in management - especially when it comes to tailoring of therapy for patients.

The bottom-line is that in the struggle between rheumatology and nephrology our specialty has already lost valuable ground. We haven't been effective in making the case that nephrology input is a key component to managing patients with LN. By also not making a strong case for the necessity of a kidney biopsy the lupus patient who gets referred to the rheumatologist will tend to stay with the rheumatologist when she (or he) develops nephritis. And the patient might even get initiated on therapy without a kidney biopsy. Surely, this doesn’t represent good patient care. Now, what was I saying about finding the authors all being rheumatologists bothersome?