Schistosomal glomerulopathies

IgA nephropathy is associated with Opisthorchis felineus liver fluke infection: Retrospective 5-year analysis of human kidney samples

OBJECTIVES

Infection with the fish-borne liver fluke Opisthorchis felineus, which is transmitted through the consumption of raw or undercooked fish, results in serious liver damage in humans. Currently, limited clinical and experimental data reveal kidney damage co-occurring with chronic opisthorchiasis. We conducted a retrospective analysis of kidney autopsy samples over a five-year period (n = 84). The aim of the study was to assess pathomorphological changes in the kidneys and evaluate whether there is an association between IgA nephropathy and liver fluke infection.

METHODS

Histological analysis, immunohistochemistry, and statistical analysis were performed.

RESULTS

In this study, we demonstrated for the first time that chronic O. felineus infection in humans was associated with tubular dystrophy, the accumulation of renal tubular casts, and glomerulosclerosis. The hypertension increases the pathomorphological changes associated with chronic opisthorchiasis. We also detected IgA and the O. felineus total antigen in glomeruli of infected people. Fisher's test showed a significant association between O. felineus infection and IgA nephropathy, as well as between O. felineus infection and glomerulosclerosis.

CONCLUSIONS

Therefore, the findings of this study highlight the importance of recognising O. felineus infection as a more than hepatobiliary disease and emphasise the need for careful, personalised monitoring of kidney function in infected individuals.

Neglected and Emerging Infections of The Kidney

Individuals, societies, and the environment are affected by neglected and emerging diseases. These diseases result in a variety of severe outcomes, including permanent disabilities, chronic diseases such as chronic kidney disease, and even mortality. Consequences include high health care expenditures, loss of means of support, social stigma, and social exclusion. The burden of these diseases is exacerbated in low- and middle-income countries owing to poverty, inadequate fundamental infrastructure, and the absence of health and social protection systems. The World Health Organization is committed to promoting the following public health strategies to prevent and control neglected tropical diseases: preventive chemotherapy; intensive case management; vector control; provision of safe drinkable water, sanitation, and hygiene; and veterinary public health. In addition, it promotes a One Health strategy, which is a collaborative, multisectoral, and interdisciplinary approach to achieving the greatest health outcomes by recognizing the interdependence of human beings, animals, plants, and their shared environment. This article provides knowledge and strategies for the prevention and treatment of neglected and emerging diseases, with a particular concentration on kidney diseases, as part of a comprehensive approach to One Health.

Infection-Related Glomerulonephritis in Children and Adults

Infection-related glomerulonephritis is an immunologically mediated glomerular injury after an infection. Glomerulonephritis may occur with the infection or after a variable latent period. Poststreptococcal glomerulonephritis (PSGN) is the prototype of infection-related glomerulonephritis. The streptococcal antigens, nephritis-associated plasmin-like receptor and streptococcal exotoxin B, have emerged as major players in the pathogenesis of PSGN. Although PSGN is the most common infection-related glomerulonephritis in children, in adults, glomerulonephritis is secondary to bacteria such as staphylococci, viruses such as hepatitis C, and human immunodeficiency virus, and, rarely, parasitic infections. Supportive therapy is the mainstay of treatment in most infection-related glomerulonephritis. Treatment of the underlying infection with specific antibiotics and antiviral medications is indicated in some infections. Parasitic infections, although rare, may be associated with significant morbidity. Poststreptococcal glomerulonephritis is a self-limiting condition with a good prognosis. However, bacterial, viral, and parasitic infections may be associated with significant morbidity and long-term consequences. Epidemiologic studies are required to assess the global burden of infection-related glomerulonephritis. A better understanding of the pathogenesis of infection-related glomerulonephritis may unravel more treatment options and preventive strategies.

Subclinical signs of podocyte injury associated with Circulating Anodic Antigen (CAA) in Schistosoma mansoni-infected patients in Brazil

BACKGROUND

The long-term effects of schistosomiasis on the glomerulus may contribute to the development of chronic kidney disease. This study aimed to investigate baseline Schistosoma mansoni-Circulating Anodic Antigen (CAA) levels and their association with kidney biomarkers related to podocyte injury and inflammation in long-term follow-up after praziquantel (PZQ) treatment.

METHODS

Schistosoma infection was diagnosed by detecting CAA in urine using a quantitative assay based on lateral flow using luminescent up-converting phosphor reporter particles. A cutoff threshold of 0.1 pg/mL CAA was used to diagnose Schistosoma infection (baseline) in a low-prevalence area in Ceará, Northeast, Brazil. Two groups were included: CAA-positive and CAA-negative individuals, both of which received a single dose of PZQ at baseline. Urinary samples from 55 individuals were evaluated before (baseline) and at 1, 2, and 3 years after PZQ treatment. At all time points, kidney biomarkers were quantified in urine and adjusted for urinary creatinine levels.

RESULTS

CAA-positive patients had increased baseline albuminuria and proteinuria and showed greater associations between kidney biomarkers. CAA levels correlated only with Vascular Endothelial Growth Factor (VEGF) (podocyte injury) levels. Increasing trends were observed for malondialdehyde (oxidative stress), monocyte chemoattractant protein-1 (inflammation marker), and VEGF. In the follow-up analysis, no relevant differences were observed in kidney biomarkers between the groups and different periods.

CONCLUSIONS

S. mansoni-infected individuals presented subclinical signs of glomerular damage that may reflect podocyte injury. However, no causal effect on long-term renal function was observed after PZQ treatment.

Time-dependent renal pathologies associated with the liver fluke infection, opisthorchiasis felinea

Fish-borne trematode infections affect the health of more than 18 million people in Russia and Asian countries. Infection of humans and other mammals with the liver fluke Opisthorchis felineus (Rivolta, 1884) is accompanied by gradual development of liver disorders. Although there is indirect evidence that opisthorchiasis may be associated with damage to other organs, direct evidence of the connection between opisthorchiasis felinea and a kidney pathology has not yet been reported. To gain first insights into the possible relation, we investigated time course profiles of blood markers of renal failure as well as renal histological changes during opisthorchiasis from 1 month to 1.5 years postinfection in golden hamsters Mesocricetus auratus. For the first time, we showed that opisthorchiasis felinea leads to the development of glomerulopathy. In particular, O. felineus infection provoked gradual increases in serum creatinine, serum glucose, and urine protein concentrations. Moreover, there was gradual accumulation of renal tubular casts and of the mesangial matrix. Although the mechanisms underlying these renal pathologies remain unclear and require further research, we can conclude that O. felineus infection causes gradual progression of glomerulopathy accompanied by tubulopathy. Thus, overall, these aberrations correlate with the time course of hepatic pathological changes in opisthorchiasis felinea.

Schistosoma japonicum infection associated with membranous nephropathy: a case report

Background

Schistosomiasis is one of the most contagious parasitic diseases affecting humans; however, glomerular injury is a rare complication mainly described with Schistosoma mansoni infection. We report a case of membranous nephropathy associated with Schistosoma japonicum infection in a Chinese man.

Case presentation

A 51-year-old Chinese male with a long history of S. japonicum infection presented to the hospital with a slowly progressing severe lower limb edema and foaming urine for over 5 months. Serum S. japonicumantigen test was positive and immunohistochemistry showed that the glomeruli were positive for the antigens. The renal pathologic diagnosis was stage III membranous nephropathy. The patient was treated with glucocorticoid, praziquantel, and an angiotensin-converting enzyme inhibitor. The edema in both lower limbs disappeared within 2 weeks, but his renal function declined progressively and proteinuria persisted after 5 months of therapy.

Conclusions

Different classes of schistosomal glomerulopathy have completely different clinical manifestation and prognosis. Therefore, efforts should focus on alleviating symptoms, prevention, and early detection. S. japonicumassociated with membranous nephropathy may show a good curative effect and prognosis. However, it is necessary to monitor the renal function in such patients.

Etiology of Kidney Diseases With Proteinuria in the Gambia/West Africa

In West Africa, kidney diseases are frequently seen, but diagnostic and therapeutic options are poor due to limited access to specialized facilities. To unravel the etiology and develop clinical guidelines, we collected clinical data and results of kidney biopsies in 121 pediatric and mostly young adult patients with edema and proteinuria in The Gambia. Workup included clinical examination, urine and serum analysis, and kidney biopsy findings. Selected cases were treated with steroids.

RESULTS

The median age was 14.9 years (range 1.8-52.0) at presentation. The most frequent underlying histologies were post-infectious glomerulonephritis (PIGN) in 38%, focal-segmental glomerulosclerosis (FSGS) in 30%, minimal change nephrotic syndrome (MCNS) in 15%, and membranous glomerulonephritis (MGN) in 10% of cases. Patients with PIGN were significantly younger and had less proteinuria and higher serum albumin levels than the other three. Infected scabies was seen more often in cases with PIGN. Clinical parameters could not distinguish patients with FSGS, MCNS, and MGN. Steroid response was prompt in patients with MCNS (remission in 10/10 cases) compared to FSGS (4/19) and MGN (0/4). In summary, the clinical histopathological correlation allows a better approach to therapy and can be the basis for urgently needed interventional studies in steroid-resistant cases.

[Nephrology in Sub-saharan Africa: Past, present, future]

Nephrology was a relatively poorly known specialty in sub-Saharan Africa until the early 1980s, because of low awareness and lack of access to diagnosis and renal replacement therapies. Nephrology has seen progress on the continent despite an unfavourable economic and geopolitical environment. With a prevalence of fewer than five nephrologists per million inhabitants, the training of nephrologists, now carried out on the continent, allowed to have more than 200 specialists trained in the last decade in French-speaking sub-Saharan Africa. Clinical and basic research is developing with quality work published from the continent in major international journals. The population receiving haemodialysis remains small, between 0 and 200 per million inhabitants. Kidney transplantation, with a prevalence between 0 and 5 per million inhabitants, is only well structured in South Africa. In this context of scarce resources, a strategy based on the prevention of non-communicable diseases in general, and chronic kidney disease in particular, should be prioritised.

Schistosoma mansoni infection as a trigger to collapsing glomerulopathy in a patient with high-risk APOL1 genotype

Background

Schistosoma mansoni schistosomiasis (SM) remains a public health problem in Brazil. Renal involvement is classically manifested as a glomerulopathy, most often membranoproliferative glomerulonephritis or focal and segmental glomerulosclerosis. We report a case of collapsing glomerulopathy (CG) associated with SM and high-risk APOL1 genotype (HRG).

Case report

A 35-year-old male was admitted for hypertension and an eight-month history of lower-limb edema, foamy urine, and increased abdominal girth. He had a recent diagnosis of hepatosplenic SM, treated with praziquantel, without clinical improvement. Laboratory tests revealed serum creatinine 1.89mg/dL, blood urea nitrogen (BUN) 24mg/dL, albumin 1.9g/dL, cholesterol 531mg/dL, low-density lipoprotein 426mg/dL, platelets 115000/mm³, normal C3/C4, antinuclear antibody (ANA), rheumatoid factor (RF), and antineutrophil cytoplasmic antibodies (ANCA), negative serologies for hepatitis C virus (HCV) and human immunodeficiency virus (HIV), HBsAg negative and AntiHBc IgG positive, no hematuria or leukocyturia, 24 hour proteinuria 6.56g and negative serum and urinary immunofixation. Kidney biopsy established the diagnosis of CG. A treatment with prednisone was started without therapeutic response, progressing to end-stage kidney disease 19 months later. Molecular genetics investigation revealed an HRG.

Conclusions

This is the first report of CG associated with SM in the setting of an HRG. This case highlights the two-hit model as a mechanism for CG pathogenesis, where the high-risk APOL1 genotype exerts a susceptibility role and SM infection serves as a trigger to CG.

Schistosomiasis mansoni is still a public health problem in Brazil and renal involvement is described. In such cases, a glomerulopathy is the typical manifestation, most often membranoproliferative glomerulonephritis. In the current article, we report a patient with a recent diagnosis of hepatosplenic SM who was admitted for nephrotic syndrome associated with reduced renal function and hypertension. Kidney biopsy established the diagnosis of collapsing glomerulopathy (CG) and molecular genetics investigation identified a high-risk APOL1 genotype (HRG). Of note, HRG has been associated with increased risk to develop CG, and a two-hit model has been proposed for the genesis of this glomerulopathy. According to this model, a HRG represents the increased-susceptibility component, while an infection or other environmental factors could act as triggers for the development of CG. Based on those data and model, our case raises SM infection as a new trigger for this severe form of glomerulopathy. This is the first description of a case of CG associated with SM in a patient with an HRG. This case corroborates the interactive role between genetic and environmental factors in the pathogenesis of CG but also identifies SM infection as an additional trigger for its development.

Novel kidney injury biomarkers in tropical infections: a review of the literature

Tropical diseases are mainly found in the tropical regions of Asia, Africa and Latin America. They are a major Public Health problem in these regions, most of them are considered neglected diseases and remain as important contributors to the development of AKI (Acute Kidney Injury), which is associated with increased patients' morbidity and mortality. In most countries, kidney disease associated to tropical diseases is attended at health services with poor infrastructure and inadequate preventive measures. The long-term impacts of these infections on kidney tissue may be a main cause of future kidney disease in these patients. Therefore, the investigation of novel kidney injury biomarkers in these tropical diseases is of utmost importance to explain the mechanisms of kidney injury, to improve their diagnosis and prognosis, as well as the assessment to health systems by these patients. Since 2011, our group has been studying renal biomarkers in visceral and cutaneous leishmaniasis, schistosomiasis, leptospirosis and leprosy. This study has increased the knowledge on the pathophysiology of kidney disease in the presence of these infections and has contributed to the early diagnosis of kidney injury, pointing to glomerular, endothelial and inflammatory involvement as the main causes of the mechanisms leading to nephropathy and clinical complications. Future perspectives comprise establishing long-term cohort groups to assess the development of kidney disease and the patients' survival, as well as the use of new biomarkers such as urinary exosomes to detect risk groups and to understand the progression of kidney injuries.

Infections and the kidney: a tale from the tropics

Tropical infections are caused by a variety of bacteria, viruses and parasitic organisms across varying geographical regions and are more often reported in adults than in children. Most of the infections are acute, presenting as a febrile illness with involvement of multiple organ systems, including the kidney. The gamut of renal manifestations extends from asymptomatic urinary abnormalities to acute kidney injury and-albeit rarely-chronic kidney disease. Tropical infections can involve the glomerular, tubulointerstitial and vascular compartments of the kidney. Leptospirosis, malaria, dengue, rickettsial fever and schistosomiasis are the most prevalent tropical infections which affect the kidneys of children living in the tropics. In this review we discuss renal involvement in these most prevalent tropical infections.

Serious Renal Disease in Egypt

We studied serious renal disease in Egypt by registering all 155 patients coming to the nephrology service at the University of Cairo during a period of 62 days in 1993. The patients presented with severe uremic symptoms. Admission creatinine and urea levels were high, 804 μmol/l and 64 mmol/l. Fifteen percent of the patients died; 115 underwent dialysis. Sixty patients presented with chronic renal failure; 53 with acute renal failure, but 24 of these were later found to have end-stage renal failure. Of 29 patients with true acute renal failure, 11 (38%) had pre-renal failure and 7 (24%) postrenal failure. Twenty-one patients were followed up after transplantation and chronic dialysis, another 17 had nephrotic syndrome, 3 hypertension, and one had asymptomatic urinary abnormalities. The most common specific etiology for chronic end-stage renal failure was diabetes mellitus type II in the older patients; second most common was Schistosoma in the younger ones. Most diabetic patients came from the city. All but one Schistosoma patient came from rural Egypt. In the 22 patients who underwent renal biopsy the most common diagnosis was mesangio capillary glomerulonephritis. The prevalence of acute renal failure, particularly iatrogenic-toxic, is increasing

Glomerular Detection of Schistosomal Antigen by Immunoelectron Microscopy in Human Mansonian Schistosomiasis

Schistosomal antigens (S. mansoni) were detected in glomeruli of nine patients with nephropathy and nephrotic syndrome by immunoelectron microscopy. The criteria for patients' selection were presence of intestinal schistosomiasis and absence of any surgical or other medical diseases, particularly lupus erythematosus, syphilis, and hepatitis B and C, which could explain the renal disease. When examined by light microscopy, kidney biopsies showed type I membranoproliferative glomerulonephritis in four patients, focal segmental glomerulosclerosis in two, and mesangioproliferative glomerulonephritis, membranous glomerulonephritis, and minimal change disease in one each of the remaining three patients. Immunofluorescence showed mainly immunoglobulin G (IgG), IgM, and different complement components (C3, Clq) deposits, particularly in the mesangial area, in eight patients. All patients had gold-labeled schistosomal antigen deposits in their glomeruli, chiefly in mesangial cells and matrix, along the glomerular membrane, and occasionally in the cytoplasm of epithelial cells. Although membranous glomerulonephritis has been rarely described in association with schistosomiasis and minimal change disease may be occasionally caused by an infectious disease like syphilis, the absence of definite experimental models and epidemiologic data suggests that coincidental pathologies without causal relationship with schistosomiasis cannot be ruled out to explain these findings.

Streptozotocin (STZ) and schistosomiasis mansoni change the biodistribution of radiopharmaceutical sodium (99m)Tc-pertechnetate in mice

INTRODUCTION

Technetium-99m ((99m)Tc) is a radionuclide commonly used in nuclear medicine to obtain (99m)Tc-radiopharmaceuticals, which can be used to evaluate either physiological processes or changes related to diseases. It is also used in some experimental studies. Streptozotocin (STZ) administration to rodents causes lesions in very early stages and induces severe and permanent diabetes. Most morbidity of schistosomiasis mansoni is attributed to a granulomatous inflammatory response and associated liver fibrosis. This study was designed to investigate whether STZ administration and schistosomiasis modify the biodistribution of the radiopharmaceutical sodium (99m)Tc-pertechnetate.

METHODS

Adult female mice were infected by exposure to 100Schistosoma mansoni cercariae (BH strain, Belo Horizonte, Brazil) and euthanized after nine weeks. STZ was administered by a single intraperitoneal injection of 100mg/kg body weight, 3 or 15days before euthanasia. Each animal received 100μl of sodium (Na) (99m)Tc-pertechnetate ((99m)TcO4(-)) (740kBq). The animals were divided into four groups: A, uninfected; B, infected; C, uninfected + STZ; and D, infected + STZ. Blood, brain, thyroid, heart, lungs, liver, spleen, pancreas and kidneys were removed. The radioactivity was counted and the percentage of the injected dose of Na(99m)TcO4 per gram of the organ (% ID/g) was determined.

RESULTS

Three days after the STZ injection, there was a decrease of Na(99m)TcO4 uptake by the liver, lungs, pancreas and kidneys (p<0.05) in group D when compared with group A. After 15days, the decrease of Na(99m)TcO4 uptake occurred also in the brain, thyroid, heart, spleen and blood (p<0.05) in group D.

CONCLUSION

We demonstrated modifications on the biodistribution of Na(99m)TcO4 due to STZ administration and schistosomiasis, possibly due to physiological alterations in some organs.

ADVANCES IN KNOWLEDGE AND IMPLICATIONS FOR PATIENT CARE

The biodistribution of radiopharmaceutical Na(99m)TcO4 should be carefully evaluated in subjects with diabetes and/or schistosomiasis infection.

Renal function in hepatosplenic schistosomiasis--an assessment of renal tubular disorders

Background

Renal involvement in Schistosoma mansoni infection is not well studied. The aim of this study is to investigate the occurrence of renal abnormalities in patients with hepatosplenic schistosomiasis (HSS), especially renal tubular disorders.

Methods

This is a cross-sectional study with 20 consecutive patients with HSS followed in a medical center in Maceió, Alagoas, Brazil. Urinary acidification and concentration tests were performed using calcium chloride (CaCl₂) after a 12-h period of water and food deprivation. The biomarker monocyte chemoattractant protein 1 (MCP-1) was quantified in urine. Fractional excretion of sodium (FE_Na+), transtubular potassium gradient (TTKG) and solute-free water reabsorption (TcH₂O) were calculated. The HSS group was compared to a group of 17 healthy volunteers.

Results

Patients' mean age and gender were similar to controls. Urinary acidification deficit was found in 45% of HSS patients. Urinary osmolality was significantly lower in HSS patients (588±112 vs. 764±165 mOsm/kg, p = 0,001) after a 12-h period of water deprivation. TcH₂O was lower in HSS patients (0.72±0.5 vs. 1.1±0.3, p = 0.04). Urinary concentration deficit was found in 85% of HSS patients. The values of MCP-1 were higher in HSS group than in control group (122±134 vs. 40±28 pg/mg-Cr, p = 0.01) and positively correlated with the values of microalbuminuria and proteinuria.

Conclusions

HSS is associated with important kidney dysfunction. The main abnormalities found were urinary concentrating ability and incomplete distal acidification defect, demonstrating the occurrence of tubular dysfunction. There was also an increase in urinary MCP-1, which appears to be a more sensitive marker of renal damage than urinary albumin excretion rate.

Monocyte chemotactic protein-1 (MCP-1) in patients with chronic schistosomiasis mansoni: evidences of subclinical renal inflammation

The aim of this study is to investigate renal markers and the biomarker MCP-1 in patients with schistosomiasis mansoni. This is a cross-sectional study with 85 patients aged 5 to 48 years, with a confirmed diagnosis of schistosomiasis mansoni through the Kato-Katz method. The patients were divided in three groups: control (G-I); infected by S. mansoni before treatment (G-II) and infected by S. mansoni after treatment (G-III). Renal function was evaluated by tubular and glomerular biomarkers and through urinary MCP-1. Patients’ mean age was 23.2±13 years. There was no statistically significant difference between the groups regarding tubular and glomerular function evaluated through the traditional biomarkers. MCP-1 was higher in G-II and G-III, when compared to G-I; p=0.009 and p=0.007, respectively. There was no difference when comparing groups G-II and G-III (p=0.892). Although it was not different among the groups, there was a significant correlation between albuminuria and MCP-1. There was a significant increase in urinary MCP-1 levels in patients with schistosomiasis mansoni, which was associated with albuminuria. This protein has a role in the recruitment of monocytes to injury and inflammation sites . The increase of MCP-1 in the urine evidences that there is silent renal inflammation in these patients and the inflammatory status is not interrupted by specific treatment of the offending agent. Our findings suggest that urinary MCP-1 can be a sensitive marker of renal injury in patients with schistosomiasis mansoni.

Human schistosomiasis: clinical perspective: review

The clinical manifestations of schistosomiasis pass by acute, sub acute and chronic stages that mirror the immune response to infection. The later includes in succession innate, TH1 and TH2 adaptive stages, with an ultimate establishment of concomitant immunity. Some patients may also develop late complications, or suffer the sequelae of co-infection with other parasites, bacteria or viruses. Acute manifestations are species-independent; occur during the early stages of invasion and migration, where infection-naivety and the host's racial and genetic setting play a major role. Sub acute manifestations occur after maturity of the parasite and settlement in target organs. They are related to the formation of granulomata around eggs or dead worms, primarily in the lower urinary tract with Schistosoma haematobium, and the colon and rectum with Schistosoma mansoni, Schistosoma japonicum, Schistosoma intercalatum and Schistosoma mekongi infection. Secondary manifestations during this stage may occur in the kidneys, liver, lungs or other ectopic sites. Chronic morbidity is attributed to the healing of granulomata by fibrosis and calcification at the sites of oval entrapment, deposition of schistosomal antigen-antibody complexes in the renal glomeruli or the development of secondary amyloidosis. Malignancy may complicate the chronic lesions in the urinary bladder or colon. Co-infection with salmonella or hepatitis viruses B or C may confound the clinical picture of schistosomiasis, while the latter may have a negative impact on the course of other co-infections as malaria, leishmaniasis and HIV. Prevention of schistosomiasis is basically geared around education and periodic mass treatment, an effective vaccine being still experimental. Praziquantel is the drug of choice in the treatment of active infection by any species, with a cure rate of 80%. Other antischistosomal drugs include metrifonate for S. haematobium, oxamniquine for S. mansoni and Artemether and, possibly, Mirazid for both. Surgical treatment may be needed for fibrotic lesions.

Parasitic kidney disease: milestones in the evolution of our knowledge

Of the 342 parasites that infect humans, 20 are associated with kidney disease, yet of these, only schistosomes, plasmodia, filariae, and leishmanias are held responsible for significant clinical or epidemiologic impact. Reviewing the evolution of human knowledge for these parasites discloses a lot of similarities regarding their discovery, patterns of kidney injury, and pathogenic mechanisms. From a historical perspective, our relevant information may be classified into 4 phases: (1) disease documentation in ancient and medieval scripts as far back as 2000-3000 bce; (2) discovery of the parasites, their life cycles, and clinical correlates by European clinicians working in African and Asian colonies during the second half of the 19th century; (3) discovery and characterization of the renal manifestations of monoparasitic infections during the second half of the 20th century; and (4) recognition of the confounding effects of coinfection with bacteria, viruses, or other parasites. The spectrum of respective kidney diseases extends all the way from acute kidney injury to glomerulonephritis, amyloidosis, urologic disorders, and malignancy. Discovery of the common immunopathogenetic host response to parasitic infections has provided a knowledge core that explains the similarities, diversities, and interactions with regard to kidney injury.

Urinary schistosomiasis: review

In this review, the clinical manifestations of urinary schistosomiasis are displayed from a pathogenetic perspective. According to the prevailing host’s immune response profile, urinary schistosomiasis may be broadly categorized into cell-mediated and immune-complex-mediated disorders. The former, usually due to Schistosoma haematobium infection, are attributed to the formation of granulomata along the entire urinary tract. As they heal with excessive fibrosis, they may lead to strictures, calcifications and urodynamic abnormalities. The main impact is lower urinary, the site of heaviest ovi-position. Secondary bacterial or viral infection is common, any may be incriminated in secondary stone formation of the development of bladder malignancy. Immune-complex mediated lesions are usually associated with hepatosplenic schistosomiasis due to Schistosoma mansoni infection. Circulating complexes composed of schistosomal gut antigens and different classes of immunoglobulins deposit in the kidneys leading to several patterns of glomerular pathology. The latter have been categorized under six classes based on the histological and immunofluorescence profile. These classes have been linked to respective clinical manifestations and depend on the stage of evolution of the host’s immune response, extent of associated hepatic fibrosis and co-infection with salmonella or hepatitis C. Secondary amyloidosis develops in 15% of such patients, representing a critical impairment of macrophage function. Conclusion: The wide clinicopathological spectrum of urinary schistosomiasis mirrors the evolution of the host’s immune response according to chronicity of infection, bacterial or viral co-infection and, in the case of glomerulonephritis, to the extent of hepatic co-morbidity.

Schistosoma hematobium-associated glomerulopathy

Schistosomiasis is the second most devastating tropical parasitic disease worldwide and is responsible for many urological complications. However, glomerular injury is a rare complication mainly described with Schistosoma mansoni. We report a case of membranoproliferative glomerulonephritis (MPGN) associated with Schistosoma hematobium infection in a young Senegalese boy living in a rural area. Clinical presentation was with steroid-resistant with nephrotic syndrome. Renal biopsy showed type 1 MPGN with the presence of S. hematobium eggs surrounded by a gigantocellular granuloma. Despite therapy with antihelminthic and immunosuppressive drugs, evolution was characterized by progression to end-stage renal disease over 1 year. More efforts should be made on the prevention and early detection of schistosomiasis among at-risk populations.

Glomerulonephritis in schistosomiasis mansoni: a time to reappraise

INTRODUCTION

The current prevalence of glomerulonephritis in patients with hepatosplenic schistosomiasis mansoni in Brazil was evaluated.

METHODS

Sixty three patients (mean age 45.5 ± 11 years) attending the outpatient infectious disease clinic of a University Hospital in Belo Horizonte, Brazil, from 2007 to 2009, were consecutively examined and enrolled in the present investigation. Diagnosis of hepatosplenic schistosomiasis was based on epidemiological, clinical and parasitological data and imaging techniques. Eight patients, who presented >30 mg/day albuminuria, were submitted to percutaneous ultrasound guided renal biopsy. Kidney tissue fragments were examined under light, direct immunofluorescence and electron microscopy.

RESULTS

All patients showed mesangial enlargement. In five, mesangial hypercellularity was observed and four presented duplication of the glomerular basement membrane. Areas of glomerular sclerosis were diagnosed in four. Deposits of immunoglobulin M and C3 were present in six samples; deposits of IgG in four, IgA in three and C1q in two samples. In all patients, immunoglobulin A was reported in the lumen of renal tubules. Deposits of kappa and lambda were observed in six samples. Electron microscopy revealed dense deposits in the glomerular tissue of three patients. Arterial hypertension, small esophageal varices, slight increases in serum creatinine and decreases in serum albumin were associated with glomerular disease.

CONCLUSIONS

Renal disease associated with hepatosplenic schistosomiasis was verified in 12.7% of patients and type I membranoproliferative glomerulonephritis was observed in 50% of them. Schistosomal glomerulopathy still is an important problem in patients with hepatosplenic schistosomiasis in Brazil.

[Pathological peculiarities of chronic kidney disease in patient from sub-Saharan Africa. Review of data from the Democratic Republic of the Congo]

Chronic kidney disease (CKD) is a major global public health problem. But kidney involvement is more common and appears more severe in Africa than in developed countries. The likely causes of end stage renal disease (ESRD) or CKD stage 3 and above in developed countries are diabetes, hypertension and less frequently glomerular diseases. In contrast, in decreasing order in Africa are glomerulopathies, hypertension and diabetes. The reasons for this preponderance of glomerular diseases are not fully known but may be linked to the persistence or reemergence of tropical diseases. This study reviews the kidney involvements more associated with common tropical diseases including HIV/AIDS. The most common HIV/AIDS lesion is a specific focal and segmental glomerulosclerosis (FSGS) termed HIV-associated nephropathy (HIV-AN). Renal complications of tropical parasites are heterogenous. Various glomerulopathies like FSGS occur during various filariasis infections. Schistosoma mansoni is responsible for membranoproliferative glomerulonephritis and amyloidosis. Human African trypanosomiasis is associated with cryoglobulinemic membranoproliferative glomerulonephritis. The Plasmodium malariae is mainly responsible for membranoproliferative glomerulonephritis. Acute patterns (acute tubular necrosis or acute postinfectious glomerulonephritis) are observed during Plasmodium falciparum infection. Several other viral, bacterial or mycobacterial infections like leprosy and tuberculosis still prevalent in Africa can also affect the kidney. Sickle cell disease is responsible for a variety of renal injuries. In conclusion, kidney lesions linked to tropical diseases partly explain the peculiar pattern of CKD of the black race and play a significant role in the current outbreak of the CKD in Subsaharan Africa.

Chronic kidney disease associated with environmental toxins and exposures

People are exposed to various potentially toxic agents and conditions in their natural and occupational environments. These agents may be physical or chemical, may enter the human body through oral, inhalational, or transdermal routes, and may exert effects on all organ systems. Several well-known as well as lesser known associations exist between chronic kidney disease (CKD) and both environmental agents and conditions, such as heavy metals, industrial chemicals, elevated ambient temperatures, and infections. The effects of these agents may be modulated by genetic susceptibility and other comorbid conditions and may lead to the development of acute and CKD. In this article, we present environmental factors that are associated with CKD.

The history of renal transplantation in the Arab world: a view from Saudi Arabia

The first successful renal transplantation in the Arab world took place in Jordan in 1972. Surprisingly, the kidney transplanted was from a non-heart-beating deceased donor. Many Arab countries followed suit, starting their transplantation programs in the 1970s and 1980s, but all were from living related donors. Very few Arab countries managed to start deceased donor programs, notable among which is the Kingdom of Saudi Arabia. Religion has an important part in personal life and government legislation in the Arab world; thus, organ procurement and transplantation had to wait for religious edicts (fatwas) to be passed about the permissibility of organ donation and brain death diagnosis before starting transplantation activities. In Saudi Arabia, the renal transplantation service went through several developmental phases, culminating in the establishment of the Saudi Center for Organ Transplantation, which has become the prototype of a successful multiorgan procurement center to be emulated by Arab and Muslim countries. The story of transplantation in the Arab world is intertwined and shaped by the prevailing socioeconomic and health indicators in the different countries. It also is the story of hard-working pioneers and of human endeavor against adversity, exemplified by 2 of the pioneers having received organ transplants. Arab countries have had more than their fair share of strife and wars, and this has impacted on transplantation services and programs.

Nephrotic syndrome in African children: lack of evidence for ‘tropical nephrotic syndrome’?

BACKGROUND

Infections such as malaria, schistosomiasis, hepatitis B and HIV have been suggested as major causes of the nephrotic syndrome (NS) in African children. We retrospectively analysed the course of the NS in 32 children from Ghana and reviewed the literature on NS from 18 different African countries for the presence of 'the tropical nephrotic syndrome'.

METHODS

Thirty-two children (22 boys, 10 girls, median age 12 years, range 1-18 years) with NS were treated from 2000-2003 at Battor Hospital, Ghana. Thirteen out of 32 children underwent a renal biopsy which was investigated by light, immune and electron microscopy. All 32 patients were initially treated with oral prednisone (PRED) therapy (29 with standard therapy for 8 weeks and three individually tailored), and steroid-resistant children received also intravenous methylprednisolone pulses (three children) or oral cyclophosphamide (two children).

RESULTS

All patients fulfilled the clinical and laboratory criteria of a NS. The initial median serum creatinine was 65 micromol/l (range 44-133 micromol/l). Renal biopsy was performed in 13/32 children and revealed focal and segmental glomerulosclerosis (FSGS) in 10 patients, minimal change disease (MCNs) in two and no conclusive result in one patient. Glomerular immune complex deposition was absent in all biopsies. After treatment with PRED, oedema disappeared in 24/32 patients; however, proteinuria normalized in 16/32 patients only. The NS relapsed in 9/16 steroid-sensitive patients after cessation of PRED therapy, and two children were frequent relapsers. The steroid-resistant NS did not respond to an intensified immunosuppression in 5/16 children receiving methylprednisolone or cyclophosphamide. Five out of 32 children died, all were steroid resistant.

CONCLUSIONS

There was no evidence for a dominating role of steroid-resistant 'tropical glomerulopathies' in children with a NS in Ghana. Similar to South Africa, focal and segmental glomerulosclerosis (FSGS) and minimal change disease were the most frequent findings on histology. Contrary to Nigeria, membrano-proliferative glomerulonephritis was not found in these patients. We conclude from this data and from the literature that the histological pattern of NS may vary between different African countries. Concerning therapy of NS under tropical conditions, we emphasize that despite the limited therapeutic facilities half of these patients may benefit from corticosteroids; however, steroid resistance and FSGS resulted in a high mortality.

End-stage renal disease in North Africa

There are many similarities in the profile of chronic renal disease in the five North African countries, reflecting their close resemblance in ethnic background, bioecology and socioeconomic standards. The incidence of renal disease is much higher than that in the West, yet the prevalence is relatively lower, which mirrors the inadequacy of medical care facilities. The principal causes of end-stage chronic renal disease (ESRD) are interstitial nephritis (14 to 32%), often attributed to environmental pollution and inadvertent use of medications; glomerulonephritis (11 to 24%), mostly mesangioproliferative and focal segmental sclerosis; diabetes (5 to 20%) and nephrosclerosis (5 to 21%). Obstructive/reflux nephropathy, attributed to urinary schistosomiasis, is common in Egypt (7%), Libya and Southern Algeria. Primary urolithiasis is a frequent cause of obstructive nephropathy in the western (hyperoxaluria) and middle (cystinuria) regions. The incidence of tuberculosis is increasing, particularly the diffuse interstitial and hematogenous forms. It is responsible also for 10 to 40% of renal amyloidosis. The latter is also frequently associated with familial Mediterranean fever. Sickle cell anemia is an important health problem in the west, leading to a wide range of glomerular and tubulointerstitial nephropathies. Takayasu disease is increasingly recognized as a cause of ischemic nephropathy and renovascular hypertension. The management of ESRD is largely influenced by late referral, co-morbidities and lack of dialysis facilities. Hemodialysis is the most frequent modality of renal replacement therapy (RRT). CAPD is used sporadically. Renal transplantation, largely from live (often unrelated) donors, is offered to less than 5% of patients with ESRD. The reported outcome of RRT generally conforms with international standards.

Overview of tropical nephrology

Tropical nephrology covers renal diseases commonly seen in the tropics and elsewhere and specific tropical renal diseases seen mostly or only in the tropical area. Emphasis in this article is placed on the latter category, which includes renal involvement in tropical infectious diseases, natural toxin poisoning, and environmental renal problems. Pathologically, all renal structures can be affected. There is, therefore, a broad spectrum of pathologic changes, and clinical renal manifestations vary from mild urinary sediment changes to acute renal failure. Inflammatory processes plays an essential role in the pathogenesis of renal involvement in infection and toxin groups. Both models share the same inflammatory pathways through cytokines, chemokines, and mediators. Hemodynamic alterations, immune response, and direct nephrotoxicity are involved in the development of renal lesions.

Nephropathy associated with animal, plant, and chemical toxins in the tropics

Widespread human exposure to a variety of drugs, chemicals, and biologic products and recent awareness of their toxic manifestations has led to the recognition of toxic nephropathy as an important segment of renal disease in the tropical countries. Tropical nephrotoxins are distinctly different from those seen in the rest of the world and are derived from local fauna and flora or plant and chemical sources. The spectrum of exposure varies from country to country and even from community to community, depending on variations in the distribution of local plants and animal species and prevalent social practices. Acute renal failure (ARF), either alone or in association with liver failure, neurologic abnormalities, metabolic acidosis, disseminated intravascular coagulation, or pulmonary infections is the most common form of presentation. Traditional medicines prescribed by witch doctors (traditional healers) constitute a special class of nephrotoxins among several communities in Africa and Asia. The prevalence of nephropathy caused by traditional medicines is directly related to a combination of ignorance, poverty, lack of medical facilities, lax legislation, and widespread belief in indigenous systems of medicine in rural areas. These medicines are a mix of herbs and unknown chemicals administered orally or as enemas. Clustering of cases after exposure to a particular agent suggests the possibility of a toxic insult. Common animal nephrotoxins are venoms of viper snakes, sea snakes, stinging insects, and raw gallbladder and bile of carp and sheep. Botanical nephrotoxins are encountered both in common edible plants (djenkol beans, mushrooms) and medicinal herbs (impila, cat's claw). Mistaken identification of medicinal herbs by untrained workers and even deliberate trials of toxic substitutes derived from plants frequently lead to renal disease, the most commonly reported being the Chinese herbal nephropathy. Nephrotoxicity caused by chemicals can be secondary to accidental occupational exposure in industrial work places (eg, chromic acid), or after suicidal or homicidal use (eg, copper sulphate, ethylene dibromide, ethylene glycol). Late presentation and multiorgan dysfunction are associated with a high mortality. A high index of suspicion, careful history taking, and an awareness of local practices are essential for proper diagnosis and management of toxic nephropathies in the tropics.

Overview: end-stage renal disease in the developing world

Although the vast majority of patients with end-stage renal disease (ESRD) worldwide live in what is called the developing world, little is known about its epidemiology and management. With the current paucity of credible and adequately representative registries, it is justified to resort to innovative means of obtaining information. In this attempt, world-renowned leading nephrologists in 10 developing countries collaborated in filling a 103-item questionnaire addressing epidemiology, etiology, and management of ESRD in their respective countries on the basis of integrating available data from different sources. Through this joint effort, it was possible to identify a number of important trends. These include the expected high prevalence of ESRD, despite the limited access to renal replacement therapy, and the dependence of prevalence on wealth. Glomerulonephritis, rather than diabetes, remains as the main cause of ESRD with significant geographical variations in the prevailing histopathological types. The implementation of different modalities of renal replacement therapy (RRT) is inhibited by the lack of funding, although governments, insurance companies, and donations usually constitute the major sponsors. Hemodialysis is the preferred modality in most countries with the exception of Mexico where chronic ambulatory peritoneal dialysis (CAPD) takes the lead. In several other countries, dialysis is available only for those on the transplant waiting list. Dialysis is associated with a high frequency of complications particularly HBV and HCV infections. Data on HIV are lacking. Aluminum intoxication remains as a major problem in a number of countries. Treatment withdrawal is common for socioeconomic reasons. Transplantation is offered to an average of 4 per million population (pmp). Recipient exclusion criteria are minimal. Donor selection criteria are generally loose regarding tissue typing, remote viral infection, and, in some countries, blood-relation to the recipient in live-donor transplants. Cadaver donors are accepted in many countries participating in this survey. Treatment outcomes with different RRT modalities are, on the average, inferior to the internationally acknowledged standards largely due to infective and cardiovascular complications.

Glomerulopathy associated with parasitic infections

Although parasitic infections do not usually present with disturbance in renal function, glomerular lesions can be seen in most of these infections. The glomerular lesions observed in parasitic infections cover the whole range of glomerular lesions known, but most of them are proliferative. Little is known of the exact pathogenic mechanisms. In this review, we try to explain the glomerular lesions associated with parasitic infections in terms of the specific immunologic events observed during these diseases against the background of recent developments in the general knowledge of the pathogenesis of glomerular disease.

Glomerulopathy associated with parasitic infections

Although parasitic infections do not usually present with disturbance in renal function, glomerular lesions can be seen in most of these infections. The glomerular lesions observed in parasitic infections cover the whole range of glomerular lesions known, but most of them are proliferative. Little is known of the exact pathogenic mechanisms. In this review, we try to explain the glomerular lesions associated with parasitic infections in terms of the specific immunologic events observed during these diseases against the background of recent developments in the general knowledge of the pathogenesis of glomerular disease.

Boné mineral density in children and adolescents with hepatosplenic mansonic schistosomiasis and esophageal varices who underwent splenectomy and ligature of the left gastric vein

Twenty eight children and adolescents from 7 to 19 years of age, suffering from hepatosplenic mansonic schistosomiasis and bleeding esophageal varices were evaluated for bone mineral density (BMD), before undergoing medical and surgical treatment. The surgical protocol was splenectomy, autoimplantation of spleen tissue into a pouch of the greater omentum and ligature of the left gastric vein. Twenty one patients were evaluated after a follow up from two to nine years post surgical treatment. The BMD was measured at the lumbar spine (L2 - L4) through the dual energy absorptionmetry X-ray (DEXA), using a LUNAR DPX-L densitometer. Preoperatively, all patients showed deficit of the BMD varying from 1 to 7.07 standard deviations (Mean <FONT FACE="Symbol">±</FONT> SEM - 2.64 <FONT FACE="Symbol">±</FONT> 0.28), considering the mean line of the control curve for healthy children accepted as normal. The BMD deficit was more evident among the females than the males. After treatment there was a significant increment (<FONT FACE="Symbol">C</FONT>2 = 9.19 - p =0.01) of the BMD and 29% of the patients (six out of twenty one) were considered without bone mineral deficit. It was concluded that the patients included in this series, who suffer from hepatosplenic mansonic schistosomiasis, showed an important BMD deficit, specially among the females which has had a significant improvement after medical and surgical treatment.

Immunology of helminth infections, with special reference to immunopathology

Immune responses resulting in immunity to infection or disease, share the same basic humoral and cellular mechanisms. While immunity to helminth infection has evolved to mediate rapid elimination of the parasite, the strategies evolved by the parasites themselves aim to delay this rejection process and ensure the survival and distribution of their progeny. Ineffective or incomplete immunity results in persistence of parasites or their products within the host tissues, inappropriate or chronic stimulation by parasite antigens, hyper-reactivity and tissue damage or immunopathology. A long standing classification by Gell and Coombs identifies four major types of hypersensitivity responses accounting for most of the immunopathogenesis, three of which are mediated by antibody and one, delayed type hypersensitivity (DTH), by T cells. This paper aims to give a short review of these four classical hypersensitivity reactions with particular reference to infections of large animals with helminth parasites. In addition, in view of the functionally different helper T cell subsets now identified, the existing DTH response is redefined as DTH Type 1 (Th-1 mediated) and two new classes of T cell-dependent DTH responses are proposed; DTH Type II, associated with the Th-2 type cytokines IL-4 and IL-5 and eosinophilic granuloma formation, and DTH Type III, associated with IL-4 and TGF-beta and fibrosis. Finally, some implications of immunopathology on parasite control strategies are discussed.

Immunoglobulin-A and the pathogenesis of schistosomal glomerulopathy

Several observations suggest that the evolution of schistosomal glomerulopathy into clinically overt and progressive disease may involve pathogenetic mechanisms other than simple glomerular deposition of parasitic antigens. In a previous study, IgA was suggested to be a mediator of late glomerular lesions in this disease. This issue is further addressed in this work. The study includes 32 patients with hepatosplenic schistosomiasis, of whom 16 had overt glomerular involvement, along with four control groups: (a) 15 healthy volunteers; (b) 15 patients with simple intestinal mansoniasis; (c) 17 patients with non-schistosomal chronic liver disease; and (d) 21 subjects with primary nephrotic syndrome not associated with schistosomiasis. Routine assessment was done for all subjects including confirmatory tests for schistosomal infection, liver and renal function tests, hepatitis viral markers and abdominal ultrasonography. The total serum concentrations of IgG, IgM, IgA were measured, as well as their respective circulating immune complexes, rheumatoid factors, anti-gliadin- and anti-DNA-antibodies. Liver and renal biopsies were obtained from the relevant groups and studied by light microscopy. Renal biopsies were also examined by immunofluorescence. Patients with simple intestinal schistosomiasis had a significant increase in IgM antigliadin antibodies. Those complicated with hepatosplenic involvement also had a significant increase in the mean IgG anti-gliadin antibodies, IgG rheumatoid factor and IgM anti-DNA activity. Cases further complicated by overt glomerular disease showed a distinct IgA predominance, mainly expressed in the serum anti-gliadin antibody pool and anti-DNA activity. This profile was essentially similar to that observed in control cirrhotics. There was a significant increase in the frequency of IgA glomerular deposits in renal biopsies obtained from patients with overt schistosomal glomerulopathy, in contrast to control nephrotics. The deposits were mainly mesangial, but were also encountered in subendothelial, subepithelial and peritubular locations. Their frequency was significantly higher with more advanced lesions as seen by light microscopy. The relevance of these data is discussed, leading to the following conclusions: (a) serum IgA-anti-gliadin and -anti-DNA antibodies, and glomerular IgA deposits are markers of significant renal involvement in patients with hepatosplenic schistosomiasis. (b) IgA may be involved in the pathogenesis of advanced glomerular pathology when superimposed on parasite-induced lesions. (c) There is a significant increase in serum auto-reactivity in hepatosplenic schistosomiasis, which may also have pathogentic implications. (d) Increased production by the inflammatory bowel lesions, impaired clearance by the fibrotic livers and probable switching of immunoglobulin synthesis are suggested to explain the observed IgA predominance in those who develop renal complications.

Glomerulopathy associated with parasitic infections

Numerous infectious diseases, among them several parasitic infectious, have been shown to be associated with glomerular disease, although the exact pathogenetic mechanisms have not yet been elucidated. In this article, Marie-Louise van Velthuysen reviews the work published on glomerulopathy associated with the most important parasitic infections, ie. malaria, schistosomiasis, leishmaniasis and irypanosomiasis.

T cells and macrophages in Trypanosoma brucei-related glomerulopathy

In a previous study, susceptibility for Trypanosoma brucei-related glomerulopathy in mice was shown to be dependent on non-major histocompatibility complex genes. Glomerular disease in this model could not be explained by the production of autoantibodies alone. In order to analyze which part of the defense system, in addition to the B-cell compartment, is involved in the development of this infection-related glomerular disease, groups of athymic (BALB/c rnu/rnu), splenectomized, or macrophage-depleted BALB/c mice were inoculated with T. brucei parasites. Polyclonal B-cell activation, invariably observed in infected BALB/c mice, was absent in BALB/c rnu/rnu mice. Glomerular disease in athymic mice, however, as defined by albuminuria and deposition of immune complexes, was not different from that seen in euthymic infected BALB/c mice. Splenectomy prior to inoculation of parasites led to a decreased incidence of albuminuria in 40% of the animals, whereas splenectomy 21 days after inoculation reduced albuminuria significantly, suggesting a role for spleen cells in the induction of glomerular disease. After macrophage depletion with liposome-encapsulated dichlorodimethylene-diphosphonate, infected BALB/c mice developed significantly higher albuminuria levels for a period up to 2 weeks after depletion. Therefore, it was concluded that the development of T. brucei-related glomerular disease is independent of thymus-matured T cells, while the involvement of macrophages in the development of proteinuria is inhibitory rather than disease inducing. Spleen cells other than thymus-dependent T cells, B cells, and macrophages should be investigated for their role in the pathogenesis of this glomerulopathy.

Schistosoma mansoni circulating polysaccharide and protein antigens recognized by sheep antisera in patients with different clinical forms of schistosomiasis before and after treatment

Two sheep antisera, one of which raised against polysaccharide (Po) and other against protein (Pt) components of Schistosoma mansoni adult worms, were assessed by ELISA for their ability to detect circulating parasite antigens in patients with different clinical forms of chronic schistosomiasis mansoni. The former antiserum detected parasite antigens in liver granulomata and the latter in renal glomeruli from schistosomiasis patients and mice experimentally infected with S. mansoni. In general, the levels and/or positivity rate of circulating antigens and specific IgG antibodies were significantly higher in patients with hepatointestinal (HI) and hepatosplenic (HS) forms than in mild intestinal (I) forms. An association between Po antigens and clinical features of the disease was observed, as the level of these antigens was low (137 ng/ml) as well as the positivity rate (7.9%) in patients with I forms; values that were intermediate (593 ng/ml and 33.3%) in those with HI forms, and high (1.563 ng/ml and 50.0%) in more severe HS forms. The Pt antigens were detected in the studied clinical forms not differing statistically but, the positivity rate was significantly higher in HS forms comparatively to I forms. The antisera studied revealed distinct circulating antigen profiles, and the prognostic value of Po and Pt antigens was suggested.