Lupus nephritis among 624 cases of systemic lupus erythematosus in Riyadh, Saudi Arabia.

The aim of this article is to study the prevalence, clinicolaboratory features, WHO histological types, therapy and renal outcome of lupus nephritis (LN) in Saudi Arabia. During the 27-year-period (1980-2006), 299 (47.9%) cases of LN were identified among the 624 cases of systemic lupus erythematosus (SLE) follow-up at King Khalid University Hospital, Riyadh. The female:male ratio in LN was 8.3:1, with a mean age of 32 years and a mean age of onset of 23 years. The WHO renal histological types were; Class I (1%), Class II (18.1%), Class III (10%), Class IV (37.1%), Class V (11.7%), and Class VI (2.7%). Azathioprine was given to 43.1% and pulse cyclophosphamide to 65.6% in combination with other drugs. Remission was seen in 226 (75.6%) patients, renal flares in 14 (4.7%), end stage renal disease (ESRD) in 27 (9.0%), death in 18 (6.0%), and 14 (4.7%) lost follow-up. The 5- and 10-year patient survival rates in our whole LN cohort by Kaplan-Meier analysis were 96% and 95%, respectively. The survival did not differ significantly in different LN classes nor did it differ significantly during the three periods of presentation (1980-1990, 1991-2000, and 2001-2006; P > 0.05). The risk factors for poor survival were found to be older age at onset (>50-years age; P = 0.034), ESRD (P = 0.000), and low C3 (P = 0.022). The risk factors for progression to ESRD were older age at onset (>50-years age; P = 0.037), hypertension (P = 0.009), elevated serum creatinine (P = 0.000), and proliferative LN (Classes III, IV; P = 0.013, P = 0.039). Different treatment modalities did not have significant effect on survival in the whole LN cohort (P = >0.05). However, pulse cyclophosphamide favored remission in Classes II, III, IV, and V (P = 0.023). The main causes of death were renal failure (50%) and infections (44.4%).