Systemic lupus international collaborating clinics renal activity/response exercise: development of a renal activity score and renal response index.
OBJECTIVE
To develop a measure of renal activity in systemic lupus erythematosus and use it to develop a renal response index.


METHODS
Abstracted data from the medical records of 215 patients with lupus nephritis were sent to 8 nephrologists and 29 rheumatologists for rating. Seven nephrologists and 22 rheumatologists completed the ratings. Each physician rated each patient visit with respect to renal disease activity (none, mild, moderate, or severe). Using the most commonly selected rating for each patient as the gold standard, stepwise regression modeling was performed to identify the variables most related to renal disease activity, and these variables were then used to create an activity score. This activity score could then be applied to 2 consecutive visits to define a renal response index.


RESULTS
The renal activity score was computed as follows: proteinuria 0.5-1 gm/day (3 points), proteinuria 0.5-1 gm/day = 3 points, proteinuria >1-3 gm/day = 5 points, proteinuria >3 gm/day = 11 points, [corrected] urine red blood cell count > = 5/hpf = 3 points, [corrected] urine white blood cell count > or = 5/hpf = 1 point. [corrected] The chance-adjusted agreement between the renal response index derived from the activity score applied to the paired visits and the plurality physician response rating was 0.69 (95% confidence interval 0.59-0.79).


CONCLUSIONS
Ratings derived from this index for rating of renal response showed reasonable agreement with physician ratings in a pilot study. The index will require further refinement, testing, and validation. A data-driven approach to create renal activity and renal response indices will be useful in both clinical care and research settings.
Department of Rheumatology, Johns Hopkins University, Baltimore, Maryland 21205, USA. mpetri@jhmi.edu
Michelle
M
Petri
Nuntana
N
Kasitanon
Shin-Seok
SS
Lee
Kimberly
K
Link
Laurence
L
Magder
Sang-Cheol
SC
Bae
John G
JG
Hanly
David A
DA
Isenberg
Ola
O
Nived
Gunnar
G
Sturfelt
Ronald
R
van Vollenhoven
Daniel J
DJ
Wallace
Graciela S
GS
Alarcón
Dwomoa
D
Adu
Carmen
C
Avila-Casado
Sasha R
SR
Bernatsky
Ian N
IN
Bruce
Ann E
AE
Clarke
Gabriel
G
Contreras
Derek M
DM
Fine
Dafna D
DD
Gladman
Caroline
C
Gordon
Kenneth C
KC
Kalunian
Michael P
MP
Madaio
Brad H
BH
Rovin
Jorge
J
Sanchez-Guerrero
Kristjan
K
Steinsson
Cynthia
C
Aranow
James E
JE
Balow
Jill P
JP
Buyon
Ellen M
EM
Ginzler
Munther A
MA
Khamashta
Murray B
MB
Urowitz
Mary Anne
MA
Dooley
Joan T
JT
Merrill
Rosalind
R
Ramsey-Goldman
Josef
J
Font
James
J
Tumlin
Thomas
T
Stoll
Asad
A
Zoma
D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D008180:Lupus Erythematosus, Systemic / Q000150:complications / Q000503:physiopathology*; D008181:Lupus Nephritis / Q000175:diagnosis*; D015588:Observer Variation; D012720:Severity of Illness Index