BACKGROUND: In the past, lupus nephritis was histologically classified according to the 1995 WHO Classification. With the introduction of the 2003 ISN/RPS Classification, many nephropathology services converted to this new classification. This study was undertaken to compare both classification systems in a single centre practice.
METHODS: 103 consecutive adequate renal biopsies initially reported as lupus nephritis in the Department of Pathology, Faculty of Medicine, University of Malaya were reassessed using the criteria of both the 1995 WHO Classification and the 2003 ISN/ RPS Classification.
RESULTS: The relative prevalence for each class using the WHO Classification were: Class I (1%), Class II (8.7%), Class III (6.8%), Class IV (60.2%), Class V (20.4%), Class VI (2.9%) while the prevalence using the 2003 ISN/RPS Classification were: Class I (1%), Class II (8.7%), Class III (6.8%), Class IV (61.2%), Class V (21.3%), Class VI (1%). Both classifications were essentially comparable with regards to Classes I, II and III. The differences in Classes IV, V and VI were significant in potential to alter patient management. The identification of segmental lesions (Class IV-S) over and above a global nephritis (Class IV-G) deserves more focused clinicopathological studies to gauge whether these groups have different clinical manifestations and outcomes. With regards Class V, the ISN/RPS system, by requiring that all mixed classes be stipulated in the diagnostic line, minimizes the chances of patients missing out on additional treatment. The ISN/ RPS system has stricter criteria for Class VI, which again minimizes patients missing out on therapy. On the whole, the ISN/RPS system is more user-friendly as criteria are more clearly defined which translates to more benefits to patient care.
Study site: Department of Pathology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
Ki-67 expression in diffuse proliferative lupus nephritis, WHO Class IV, was compared against normal controls to establish that cellular proliferation is involved in the production of glomerular hypercellularity. Twenty-three histologically confirmed WHO Class IV lupus nephritis and 23 normal control renal tissue were immunohistochemically stained with a polyclonal antibody to Ki-67 (Dako) using the peroxidase labelled streptavidin bioitin kit (Dako). There were 20 females and 3 males, with 17 Chinese and 6 Malays in the WHO Class IV lupus nephritis group. Ages of patients ranged between 10-56 years with a mean of 31.9 years. The normal controls, 20 males and 3 females, and ethnically 9 Indians, 7 Malays, 2 Chinese, and 5 foreign nationals (4 Indonesians and 1 Bangladeshi), had an age range between 15-33 years (mean = 23.3 years). Sixteen (69.6%) WHO Class IV lupus nephritis and 8 (34.8%) normal controls demonstrated Ki-67 immunoreactivity in at least 1 glomerulus (p<0.05). Of the 256 WHO Class IV lupus nephritis non-sclerosed, glomeruli studied, 37 (14.5%) were Ki-67 immunopositive compared with normal controls where 16 (0.7%) of 2159 glomeruli demonstrated Ki-67 (p< 0.01). Cellular proliferative activity, as evidenced by Ki-67 expression, was significantly increased in WHO Class IV lupus nephritis confirming that cell proliferation contributes to glomerular hypercellularity.
OBJECTIVES: To determine the pattern of renal histology, clinical outcome of children with lupus nephritis and to identify any associated risk factors predicting renal failure in these children.
METHODS: Retrospectively, 27 children under 16 years of age with lupus nephritis who had renal biopsies done at Sultanah Aminah Hospital Johor, Malaysia from 1994 to 2002 were studied. The renal histology was graded according to WHO classification system (1982). The medical records, laboratory data and the clinical outcome of the patients were studied.
RESULTS: There were 24 cases of WHO Class IV, two cases of WHO Class II and a case of WHO Class V. Twenty children were in the good renal outcome group while six children progressed into the poor renal outcome group and required renal replacement. One child was lost to follow-up. All six children in the poor renal outcome group had WHO Class IV histology. The 5-year patient and renal survival rates were 84% and 75%, respectively. Age, sex, activity and chronicity indices in the renal histology, anaemia, elevated serum creatinine, depressed levels of C3 and C4, heavy proteinuria or presence of urinary active sediments were not associated with progression to renal failure.
CONCLUSIONS: Presently, children with lupus nephritis appeared to have better patient and renal survival rates. Assessment of renal histology in these children was important for diagnosis, treatment and probably prognosis. In this study, there was a 25% incidence of loss of renal function over 5 years in children with WHO Class IV renal histology.