Kidney involvement in psoriasis: a case-control study from China.

PURPOSE: Kidney involvement secondary to psoriasis is still a controversial issue. In this study, we aimed to evaluate the prevalence of urinary abnormalities in psoriasis patients and to find out whether the abnormality is related to the severity of psoriasis.

METHODS: Ninety-seven psoriasis patients (62 females, 35 males, mean age 35.74 ± 13.45 years) and ninety-six age- and gender-matched control subjects (58 males, 38 females, mean age 35.82 ± 13.48 years) without hypertension or diabetes were enrolled in this study. Psoriasis area and severity index (PASI) was used to assess the severity of psoriasis. Twenty-four-hour proteinuria, albuminuria, RBP, and NAG were measured in all patients and controls. Pathologic proteinuria was defined as the total protein excretion of more than 0.4 g/24 h, as measured by the turbidimetric assay. Pathologic albuminuria was defined as albumin excretion of more than 17 mg/24 h. Pathologic NAG and RBP were defined as the excretion of more than 16.5 u/g cr and 0.5 mg/L, respectively.

RESULTS: Increased 24-h microalbuminuria (11.53 ± 7.29 vs. 9.79 ± 3.72, P = 0.039) and 24-h proteinuria (0.24 ± 0.21 vs. 0.18 ± 0.09, P = 0.002) were found in patients with psoriasis compared with controls. Patients with psoriasis had an increased prevalence of pathological albuminuria (15.46 vs. 5.21%, P = 0.019), NAG (10.31 vs. 3.13%, P = 0.046), and RBP (9.28 vs. 2.08%, P = 0.031) compared with controls. PASI scores in patients with psoriasis correlated positively with 24-h albuminuria (χ 2  = 10.75, P = 0.005).

CONCLUSIONS: The prevalence of abnormal urinalysis was more common in patients with psoriasis than in controls. The positive correlation between the prevalence of pathological albuminuria and psoriasis severity may indicate a subclinical renal dysfunction in patients with psoriasis.