[The significance of urinary podocytes in patients with active lupus nephritis].
OBJECTIVE
To assess the significance of urinary podocyte and its possible implication as a marker of activity of lupus nephritis.


METHODS
The presence of podocytes in urinary sediment was detected with immunochemical staining using anti-podocalyxin antibody. The correlation of the number of urinary podocytes with activity index of renal pathological lesions, hematuria, and proteinuria was analyzed respectively. The proliferating podocytes in renal biopsy tissue and urine from patients with class IV lupus nephritis were examined with double immunohistochemical staining.


RESULTS
Thirty-one patients with lupus nephritis undergoing renal biopsy were enrolled into the study. Renal pathological findings of the patients could be classified into WHO class III (25.8%), class IV (64.5%) and class V (9.7%). 90% of the patients had positive urinary podocytes. The number of urinary podocytes was strongly and positively correlated with the severity of hematuria (r=0.639, P=0.000) and glomerular pathological activity index (r=0.487, P=0.014) in patients of class III and class IV. The amount of proteinuria was not correlated with pathological activity index, even though all the patients had proteinuria. Furthermore, the number of urinary podocytes, the severity of hematuria and the amount of proteinuria were all decreased after treatment with methyl prednisone, cyclophosphamide or mycophenolate mofetil. Interestingly, the urinary podocytes could disappear even before the remission of hematuria and proteinuria after treatment. Proliferative podocytes were observed both in biopsied kidney tissue and urinary sediments in patients of class IV.


CONCLUSIONS
The presence and the number of urinary podocytes can be used as a valuable marker to grade the activity of lupus nephritis and to evaluate the efficacy of steroid therapy.
Li
Jing-zi
JZ
Renal Division, Peking University First Hospital, Beijing 100034, China. jingzi@bjmu.edu.cn
Liu
Ying
Y
E
Jie
J
Huang
Hai-chang
HC
Yu
Feng
F
Zou
Wan-zhong
WZ
Wang
Hai-yan
HY
D000328:Adult; D002452:Cell Count; D005260:Female; D006417:Hematuria / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D007668:Kidney / Q000166:cytology; D007678:Kidney Glomerulus / Q000473:pathology*; D008181:Lupus Nephritis / Q000473:pathology* / Q000652:urine; D008297:Male; D008875:Middle Aged; D050199:Podocytes / Q000166:cytology*; D018809:Proliferating Cell Nuclear Antigen / Q000276:immunology; D011507:Proteinuria / Q000473:pathology; D012795:Sialoglycoproteins / Q000276:immunology; D014556:Urine / Q000166:cytology
D018809:Proliferating Cell Nuclear Antigen; D012795:Sialoglycoproteins; C001643:podocalyxin