Immunological aspects of nephrotic syndrome in northern Nigeria

Global prevalence and mortality of severe Plasmodium malariae infection: a systematic review and meta-analysis

Background

Severe complications among patients with Plasmodium malariae infection are rare. This is the first systematic review and meta-analysis demonstrating the global prevalence and mortality of severe P. malariae infection in humans.

Methods

The systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. All research articles published on the severity and mortality of P. malariae infection cases in humans were retrieved from three public databases: PubMed, Scopus, and ISI Web of Science. The pooled prevalence estimate and 95% confidence interval (CI) of complications in patients with P. malariae malaria was analysed using the random-effects model provided in Stata software. The pooled odds ratio (OR) and 95% CI of severe malaria for P. malariae infection and Plasmodium falciparum infection were analysed using Review Manager software.

Results

Six studies were used to estimate the pooled prevalence of severe P. malariae malaria. Out of 10,520 patients infected with P. malariae, the pooled prevalence estimate of severe P. malariae infection was 3% (95% CI 2–5%), with high heterogeneity (I²: 90.7%). Severe anaemia (3.32%), pulmonary complications (0.46%), and renal impairments (0.24%) were the most common severe complications found in patients with P. malariae infection. The pooled proportion of severe anaemia for P. malariae infection and P. falciparum infection was comparable among the four included studies (OR: 0.74, 95% CI 0.22–2.45, I² = 98%). The pooled proportion of pulmonary complications was comparable between patients with P. malariae infection and those with P. falciparum infection among the four included studies (OR: 1.44; 95% CI 0.17–12.31, I²: 92%). For renal complications, the funnel plot showed that the pooled proportion of renal complications for P. malariae infection and P. falciparum infection was comparable among the four included studies (OR: 0.94, 95% CI 0.18–4.93, I²: 91%). The mortality rate of patients with P. malariae infection was 0.17% (18/10,502 cases).

Conclusions

This systematic review demonstrated that approximately two percent of patients with P. malariae infection developed severe complications, with a low mortality rate. Severe anaemia, pulmonary involvement, and renal impairment were the most common complications found in patients with P. malariae infection. Although a low prevalence and low mortality of P. malariae infection have been reported, patients with P. malariae infection need to be investigated for severe anaemia and, if present, treated aggressively to prevent anaemia-related death.

High Steroid Sensitivity among Children with Nephrotic Syndrome in Southwestern Nigeria

Recent reports from both Caucasian and black populations suggest changes in steroid responsiveness of childhood nephrotic syndrome. This study was therefore undertaken to determine the features and steroid sensitivity pattern of a cohort of black children with nephrotic syndrome. Records of children managed for nephrotic syndrome from January 2008 to April 2013 were reviewed. Details including age, response to treatment, and renal histology were analysed. There were 108 children (median age: 5.9 years, peak: 1-2 years), 90.2% of whom had idiopathic nephrotic syndrome. Steroid sensitivity was 82.8% among children with idiopathic nephrotic syndrome but 75.9% overall. Median time to remission was 7 days. Median age was significantly lower in steroid sensitive compared with resistant patients. The predominant histologic finding in resistant cases was focal segmental glomerulosclerosis (53.3%). No cases of quartan malaria nephropathy or hepatitis B virus nephropathy were diagnosed. Overall mortality was 6.5%. In conclusion, unusually high steroid sensitivity is reported among a cohort of black children. This is likely attributable to the lower age structure of our cohort as well as possible changing epidemiology of some other childhood diseases. Surveillance of the epidemiology of childhood nephrotic syndrome and corresponding modifications in practice are therefore recommended.

Glomerulonephropathies in Plasmodium inui-infected rhesus monkey: a primate model and possible applications for human quartan malaria

SUMMARY None of the few animal models proposed for the study of human quartan malaria nephritic syndrome have shown complete pathological findings that are similar to those seen in humans. This study investigated the histopathological changes in kidneys in 10 Plasmodium inui infected Macaca mulatta monkeys by light and electron microscopy in order to develop a suitable animal model for human quartan malaria. Ten healthy adult rhesus monkeys were infected with P. inui and clinical chemistry and haematologic tests were done before and after infection. A renal biopsy sample was collected before infection as a baseline control and another biopsy was collected after infection. Histopathological changes examined by light and transmission electron microscopy (TEM) revealed abnormalities in all infected monkeys to variable degrees. Several electron-dense discrete or diffused mesangial deposits, and increase in mesangial cells and matrix were associated with the morphological changes observed by light microscope. This pattern is consistent with membranoproliferative glomerulonephritis type reported in humans infected with Plasmodium malariae. Results strongly support that the P. inui-infected rhesus monkey develop an immune-complex-mediated glomerulonephritis in the course of the infection. Therefore, this experimental model represents a useful tool to better understand the different parameters and the consequences of quartan malaria infections comparable to situations in humans.

Biology of human malaria plasmodia including Plasmodium knowlesi

Malaria is a vector-borne infection caused by unicellular parasite of the genus Plasmodium. Plasmodia are obligate intracellular parasites that are able to infect and replicate within the erythrocytes after a clinically silent replication phase in the liver. Four species (P.falciparum, P.malariae, P.ovale and P.vivax) are traditionally recognized as responsible of natural infection in human beings but the recent upsurge of P.knowlesi malaria in South-East Asia has led clinicians to consider it as the fifth human malaria parasite. Recent studies in wild-living apes in Africa have revealed that P.falciparum, the most deadly form of human malaria, is not only human-host restricted as previously believed and its phylogenetic lineage is much more complex with new species identified in gorilla, bonobo and chimpanzee. Although less impressive, new data on biology of P.malariae, P.ovale and P.vivax are also emerging and will be briefly discussed in this review.

Nephrotic syndrome and unrecognized Plasmodium malariae infection in a US Navy sailor 14 years after departing Nigeria

A 34-year-old Nigerian man presented with nephrotic syndrome. Renal biopsy revealed chronic membranous glomerulopathy with focal segmental sclerosis. Blood Giemsa smear contained rare Plasmodium sp. trophozoites and small subunit ribosomal RNA polymerase chain reaction amplification confirmed the presence of Plasmodium malariae. This case highlights the importance of obtaining even remote travel histories from ill immigrants and considering occult quartan malaria in patients from endemic locations with nephrotic syndrome.

The 'non-falciparum' malarias: the roles of epidemiology, parasite biology, clinical syndromes, complications and diagnostic rigour in guiding therapeutic strategies

Plasmodium vivax, P. ovale, P. malariae and P. falciparum routinely infect humans. The infections caused by these parasites are loosely referred to as vivax (or benign tertian), ovale, malariae (or quartan) and falciparum (or malignant tertian) malaria, respectively. Recently, P. knowlesi, a parasite of macaque monkeys in South-east Asia, has been identified as the cause of uncomplicated and severe human malaria in Malaysian Borneo. The prescription of appropriate therapies for reliably diagnosed malaria requires a grasp of the epidemiology of the 'non-falciparum' malarias, the biology of the parasites involved, the chemotherapeutic strategies that are available and the problems of emerging drug resistance and changing clinical syndromes. This review is intended to increase clinicians' understanding of how these factors relate to the selection of the antimalarial drugs to be given to a case of 'non-falciparum' malaria, with the aims of improving outcomes and preventing relapses and recrudescences.

Childhood nephrotic syndrome: change in pattern and response to steroids

BACKGROUND

In our center, childhood nephrotic syndrome (NS) had been reported for over a decade to be steroid sensitive contrary to reports in other parts of Nigeria. The purpose of this study was to determine if there are changes in presentation and response to steroids, with reviews of the literature on NS.

METHODS

Analysis of 28 patients seen at the University of Port Harcourt Teaching Hospital, Nigeria, from 1999-2004 with the diagnosis of NS was performed.

RESULTS

There were 14 girls and 14 boys with NS. The peak age was 1-4 years. Twenty (71.4%) children had idiopathic nephrotic syndrome (INS). Four had chronic renal failure, one had sickle cell disease (HbSS), two were positive to human immunodeficiency virus (HIV) 1 and 2, and one had pulmonary tuberculosis. Anemia was found in 13 patients, while 17 had Plasmodium falciparum. Plasmodium malariae and hepatitis-B surface antigen were not isolated. Renal biopsy was performed in four patients and revealed minimal-change disease in one child, focal segmental glomerulosclerosis in two and no conclusive result in one patient. Oral prednisolone was used in INS. After one month of therapy, 16 of 20 responded, of which 12 (75%) were <5 years. The NS relapsed in 15 of 16 steroid-sensitive patients. Cyclophosphamide and levamisole were used in four and one patients with FRNS, respectively. Four (14.3%) patients died; all were secondary NS.

CONCLUSION

INS remains common in our center, and the majority respond to steroid therapy

Renal disorders in children: a Nigerian study

A 5-year prospective study of 699 children with various renal disorders from around the Rivers State, which is in the eastern part of Nigeria, was carried out to investigate the prevalence and significance of renal disorders in a third world country with no facilities for paediatric dialysis and transplantation. Renal disorders accounted for 1.1% of the total outpatients and hospital admissions. The commonest renal disorders were urinary tract infection (UTI, 68.9%); nephrotic syndrome (NS 14.6%) and acute post streptococcal glomerulonephritis (11.4%). Patients with UTI had no vesico-ureteric reflux (VUR); 22.5% of NS patients were steroid sensitive. Wilms' tumour (1.6%) was the second commonest childhood malignant tumour; 8 of 17 cases of obstructive uropathy were secondary to meatal stenosis following circumcision. Fifteen children developed end-stage renal failure (ESRF), mainly due to chronic glomerulonephritis, giving a prevalence rate of 7.5 children per year per million childhood population. Hence, renal disorders are common in Nigeria and although VUR is rare, ESRF may approximate figures seen in the western world. This highlights the need to improve the country's socioeconomic conditions, make medical facilities more available to children and prevent renal diseases that may lead to ESRF.

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.

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

Hepatitis B surface antigen was detected by radioimmunoassay in the sera of 18 out of 50 (36%) children with nephrotic syndrome and in 28 of 61 (45.9%) controls. Immunofluorescent studies of kidney biopsies showed HBsAg, IgG, IgM and C3 deposits in a granular pattern in the biopsies of 12 children with nephrotic syndrome and in none of the control kidney biopsies, even though there was no significant difference between the frequencies of HBsAg in the sera of these two groups. We conclude that these findings are indicative of an aetiologic role for HBsAg in these patients.