The role of hepatitis B surface antigen in Nigerian children with nephrotic syndrome

Kidney disease in hepatitis B surface antigen-positive children: experience from a centre in south-west Nigeria and a review of the Nigerian literature

BACKGROUND

Kidney disease is an important extra-hepatic manifestation of hepatitis B virus (HBV) infection. However, there is paucity of recent literature on kidney disease in children and adolescents with HBV infection from several parts of sub-Saharan Africa including Nigeria.

OBJECTIVE

To review the pattern of kidney disease in hepatitis B surface antigen (HBsAg)-positive children and adolescents seen at a tertiary hospital in south-west Nigeria.

METHODS

A retrospective study was undertaken of HBsAg-seropositive children with kidney disease managed at University College Hospital, Ibadan, from January 2004 to December 2015. Patients were identified from the paediatric nephrology unit admissions and the renal histology registers.

RESULTS

24 children and adolescents were studied, 17 of whom were male (70.8%), and the median age was 10.0 years (range 3-15). Ten (41.7%) had nephrotic syndrome, five (20.8%) had non-nephrotic glomerulonephritis, five (20.8%) were in end-stage renal disease (ESRD), including a patient with posterior urethral valves, and four had acute kidney injury secondary to acute tubular necrosis. Renal histology was available for 10 patients: nine had nephrotic syndrome associated with minimal change disease in six, focal segmental glomerulosclerosis in two and one had membanoproliferative glomerulonephritis. The patient with non-nephrotic glomerulonephritis had diffuse global sclerosis.

CONCLUSION

The pattern of kidney disease in HBV-positive children demonstrated a predominance of nephrotic syndrome, followed by non-nephrotic glomerulonephritis, ESRD and acute kidney injury. Better diagnostic facilities and treatment are required. Prevention of HBV infection by universal childhood immunisation is the ultimate goal.

Childhood nephrotic syndrome in tropical Africa: then and now

This descriptive and comparative review examines the changing epidemiology, treatment, renal and patient outcome of childhood nephrotic syndrome (NS) in tropical Africa (TpAfr). In the 1960s to 1980s, corticosteroid-resistant non-minimal change disease (nMCD) including quartan malaria nephropathy (QMN) was the dominant renal histopathology type. The overall incidence of NS was 0.35-1.34% of hospital admissions. Median age at onset of NS ranged between 4.0 and 12.0 years while the mean (SD) age range was 5.8 (3.8) to 10.3 (4.8) years across studies. The male: female ratio was 1.6:1.0. The overall mean (SD) incidence of idiopathic minimal change disease (MCD) [21.6 (18.6%)] compared with idiopathic nMCD [59.1 (25.7%)] demonstrates significant dominance of the latter (p = 0.0001). Post-1989, the following mean (SD) incidences of histopathological types were: MCD 20.4 (17.7%), focal segmental glomerulosclerosis 39.0 (26.3%), membranoproliferative glomerulonephritis 25.4 (16.8%), proliferative glomerulonephritis 16.7 (27.0%) and membranous nephropathy 7.4 (4.5%). While the mean (SD) proportion of steroid resistance (SR) [73.5 (19.2%)] was significantly greater than the mean complete remission (CR) [26.5 (19.2%)] during 1960-1989 (p=0.005), mean (SD) SR [27.4 (25.3%)] was significantly lower than mean (SD) CR [66.1 (28.0%)] post-1989 (p < 0.001). Unlike QMN, hepatitis B virus, HIV infection, sickle cell disease and systemic lupus erythematosus are now increasingly being associated with NS in TpAfr. Mean (SD) renal survival post-1989 was 58.3 (37.0%) while all-cause mortality was 9.8%. Children with NS now survive better than before, reflecting improved access to healthcare and transition to a clinical pattern favouring idiopathic NS and increased sensitivity to corticosteroids.

[Primary nephrotic syndrome in the black African child]

Idiopathic nephrotic syndrome (INS) in black African children differs from that of children in temperate areas. The main differences are the high rate of corticosteroid non-responders and the low rate of minimal change glomerulopathy in black African children, possibly related to a racial factor. The identification of a high corticosensibility in certain African regions (Togo and Ghana) can lead to the identification of an ethnic factor. Further genetic studies should be carried out in order to provide a better approach to INS in Africa.

Childhood renal disorders in Nigeria

The common childhood renal disorders in Nigeria are post-infectious acute glomerulonephritis (PIAGN), nephrotic syndrome, hypertension, congenital anomalies and urinary tract infection. Children with PIAGN often present with hypertension, circulatory overload and hypoalbuminaemia. Nephrotic syndrome is characterized by a paucity of minimal change and a poor prognosis. Posterior urethral valves and hydronephrosis are the most frequent congenital anomalies. Children with congenital anomalies present late with advanced disease. The commonest malignancy is nephroblastoma, but Burkitt's lymphoma of the kidney also occurs. Both acute and chronic renal failure present depressing and distressing clinical problems, with an aggressive course and a high morbidity and mortality. Poor socio-economy has adverse effects on the presentation, management and follow-up of Nigerian children with renal disorders.

Fulminant hepatic failure in nephrotic syndrome related to withdrawal of immunosuppressive therapy

Two patients with nephrotic syndrome developed fatal fulminant hepatitis B following withdrawal of prednisolone or cyclophosphamide. Immunosuppressive therapy probably enhanced hepatitis B virus (HBV) replication and widespread infection of hepatocytes; its withdrawal permitted a return of immune competence resulting in massive destruction of infected hepatocytes. Prior screening of all patients for hepatitis B surface antigen, gradual withdrawal of immunosuppressive drugs with careful monitoring, and prompt intervention with corticosteroids at the first clinical or biochemical signs of liver cell damage may prevent this complication.

The role of infectious agents in the aetiology and pathogenesis of childhood nephrotic syndrome in Africa

Childhood nephrotic syndrome is common in Africa where infectious agents are prevalent. This paper reviews the possible aetiological role of infectious agents in childhood nephrotic syndrome in Africa. There is a strong association, possibly causal, between childhood nephrotic syndrome on the one hand and Plasmodium malariae, Schistosoma mansoni and hepatitis B antigens on the other. Beta-haemolytic streptococci are less strongly associated with nephrotic syndrome, and a few other organisms are suspect. The many ubiquitous infectious agents and the prevalence of multiple infections make it difficult to define the role of any single infectious agent or to determine the interaction between the various agents. Control or eradication of infectious diseases should lower the incidence of childhood nephrotic syndrome in Africa.