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.
Petri
Michelle
M
Department of Rheumatology, Johns Hopkins University, Baltimore, Maryland 21205, USA. mpetri@jhmi.edu
Kasitanon
Nuntana
N
Lee
Shin-Seok
SS
Link
Kimberly
K
Magder
Laurence
L
Bae
Sang-Cheol
SC
Hanly
John G
JG
Isenberg
David A
DA
Nived
Ola
O
Sturfelt
Gunnar
G
van Vollenhoven
Ronald
R
Wallace
Daniel J
DJ
Alarcón
Graciela S
GS
Adu
Dwomoa
D
Avila-Casado
Carmen
C
Bernatsky
Sasha R
SR
Bruce
Ian N
IN
Clarke
Ann E
AE
Contreras
Gabriel
G
Fine
Derek M
DM
Gladman
Dafna D
DD
Gordon
Caroline
C
Kalunian
Kenneth C
KC
Madaio
Michael P
MP
Rovin
Brad H
BH
Sanchez-Guerrero
Jorge
J
Steinsson
Kristjan
K
Aranow
Cynthia
C
Balow
James E
JE
Buyon
Jill P
JP
Ginzler
Ellen M
EM
Khamashta
Munther A
MA
Urowitz
Murray B
MB
Dooley
Mary Anne
MA
Merrill
Joan T
JT
Ramsey-Goldman
Rosalind
R
Font
Josef
J
Tumlin
James
J
Stoll
Thomas
T
Zoma
Asad
A
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