Pathology of renal diseases in the tropics

Clinical Characteristics of Acute Kidney Injury Associated with Tropical Acute Febrile Illness

Tropical acute febrile illness (TAFI) is one of the most frequent causes of acute kidney injury (AKI). The prevalence of AKI varies worldwide because there are limited reports available and different definitions are used. This retrospective study aimed to determine the prevalence, clinical characteristics, and outcomes of AKI associated with TAFI among patients. Patients with TAFI were classified into non-AKI and AKI cases based on the Kidney Disease Improving Global Outcomes (KDIGO) criteria. Of 1019 patients with TAFI, 69 cases were classified as having AKI, a prevalence of 6.8%. Signs, symptoms, and laboratory results were significantly abnormal in the AKI group, including high-grade fever, dyspnea, leukocytosis, severe transaminitis, hypoalbuminemia, metabolic acidosis, and proteinuria. 20.3% of AKI cases required dialysis and 18.8% received inotropic drugs. Seven patients died, all of which were in the AKI group. Risk factors for TAFI-associated AKI were being male (adjusted odds ratio (AOR) 3.1; 95% CI 1.3–7.4), respiratory failure (AOR 4.6 95% CI 1.5–14.1), hyperbilirubinemia (AOR 2.4; 95% CI 1.1–4.9), and obesity (AOR 2.9; 95% CI 1.4–6). We recommend clinicians investigate kidney function in patients with TAFI who have these risk factors to detect AKI in its early stages and offer appropriate management.

Intermittent Online Postdilution Hemodiafiltration versus High-Flux Hemodialysis in Non-critical Acute Kidney Injury: A Pilot Randomized Controlled Trial

The preferential use of convective modes of hemodialysis (HD) for targeting hyper-cytokinemia state in sepsis-related acute kidney injury (AKI) has been questioned for its efficacy. Several studies have used predilution hemodiafiltration (HDF) in critically ill AKI patients with mixed results. In this study, we compared intermittent online postdilution HDF with the standard high-flux (HF) intermittent HD in non-critically ill patients with community-acquired (CA) AKI. In this pilot study, stable patients with CA AKI and systemic inflammatory response syndrome were included and given either postdilution online-HDF (OL-HDF) or standard HF HD outside intensive care units. The primary objectives were to assess the feasibility of conducting the study at a larger scale and to detect the differential impact of convective clearance on the rates of independence from dialysis at discharge or after 30 days. Plasma cytokine clearance was assessed as a secondary objective. Eighty consecutive AKI patients were randomized to receive dialysis in one of the treatment arms after fulfilling the eligibility criteria. The baseline parameters of clinical severity, etiology, and indications of dialysis, plus the baseline plasma cytokine profiles, were comparable. Moreover, 83% in the control arm and 71.1% in the intervention arm became independent from dialysis at discharge or at 30 days (P = 0.189). No survival advantage of postdilution OL-HDF was observed (P >0.05). Similar plasma cytokine clearance levels were noted in both arms. The current study confirms the feasibility; however, it does not support the preferential use of postdilution OL-HDF over HF-HD in non-critical patients.

Brazilian Dengue Virus Type 2-Associated Renal Involvement in a Murine Model: Outcomes after Infection by Two Lineages of the Asian/American Genotype

Dengue virus type 2 (DENV-2) is, traditionally, the most studied serotype due to its association with explosive outbreaks and severe cases. In Brazil, almost 20 years after the first introduction in the 1990s, a new lineage (Lineage II) of the DENV-2 Asian/American genotype emerged and caused an epidemic with severe cases and hospitalizations. Severe dengue includes multiple organ failure, and renal involvement can be potentially related to increased mortality. In order to better understand the role of DENV infection in renal injury, here we aimed to investigate the outcomes of infection with two distinct lineages of DENV-2 Asian/American genotype in the kidney of a murine model. BALB/c mice were infected with Lineages I and II and tissues were submitted to histopathology, immunohistochemistry, histomorphometry and ultrastructural analysis. Blood urea nitrogen (BUN) was detected in blood sample accessed by cardiac puncture. A tendency in kidney weight increase was observed in mice infected with both lineages, but urea levels, on average, were increased only in mice infected with Lineage II. The DENV antigen was detected in the tissue of mice infected with Lineage II and morphological changes were similar to those observed in human dengue cases. Furthermore, the parameters such as organ weight, urea levels and morphometric analysis, showed significant differences between the two lineages in the infected BALB/c, which was demonstrated to be a suitable experimental model for dengue pathophysiology studies in kidneys.

Predictors and Outcomes of Dengue-Associated Acute Kidney Injury

Dengue viral infections present with a wide clinical spectrum ranging from asymptomatic to severe manifestations with organ involvement. The term "expanded dengue syndrome" has been commonly used to illustrate the unusual or atypical manifestations; acute kidney injury (AKI) is one of the atypical manifestations of this syndrome. The use of heterogeneous criteria to determine the presence of AKI in dengue patients due to the vast diversity in populations led to difficulties in assessing the true incidence of dengue-associated AKI. This review presents a variable, but often high, frequency of dengue-associated AKI among vastly diverse populations with various disease severities. Dengue-associated AKI is not an uncommon complication, and its importance has often been neglected during the management of dengue patients. The risk factors and certain clinical and laboratory findings commonly reported among dengue patients with AKI should be considered to support a timely diagnosis and case management. This review highlights the need for clinicians to be aware of dengue-associated AKI to reduce the morbidity and mortality associated with this common and important tropical disease.

Association between renal function and co-infection with Clonorchis sinensis and Helicobacter pylori: a cross-sectional study

Background

Studies have shown that liver fluke infections may be associated with kidney injury and that Helicobacter pylori (Hp) may be involved in the pathogenesis of kidney diseases. However, no studies have reported the relationship between co-infection with Clonorchis sinensis (Cs) and Hp and renal function. The aim of this study was to examine the relationship between co-infection with Cs and Hp and estimated glomerular filtration rate (eGFR) in a general population, and gender-related differences were also investigated.

Methods

In the cross-sectional study, 4122 subjects from the Health Examination Center of Guangdong Provincial Hospital of Integrated Traditional Chinese and Western Medicine from January 2017 to December 2018 were enrolled. All participants underwent stool examination for the diagnosis of Cs infection and ¹³C-urea breath test (UBT) for the diagnosis of Hp infection. Participants were categorized into four groups: (1) co-infection with Cs and Hp group comprising 207 cases (Hp(+) + Cs(+) group), (2) Cs infection group comprising 1392 cases (Hp(−) + Cs(+)group), (3) Hp infection group comprising 275 cases (Hp(+) + Cs(−) group), and (4) non-infection group comprising 2248 cases (Hp(−) + Cs(−) group). Multiple linear regression analysis was performed to evaluate the relationship between co-infection with Cs and Hp and eGFR.

Results

Hp infection without Cs infection was present in 6.67% (275/4122) of subjects, while Cs infection without Hp infection was present in 33.77% (1392/4122) of subjects. Co-infection with Hp and Cs were present in 5.02% (207/4122) of subjects. Median age of the participants was 43 years (IQR 35–51). Most of the participants were male (2955/4122, 71.69%). Median eGFR was 96.61 ml/min/1.73 m² (IQR 85.05–106.24). Co-infection with Cs and Hp was negatively associated with eGFR after full adjusting (β = − 1.89, 95% CI: − 3.33 to − 0.45, p = 0.01). The relationship remained significant in females (β = − 9.37, 95% CI: − 11.60 to − 7.1, p < 0.001), but not in males.

Conclusion

Our findings suggest that co-infection with Cs and Hp may be associated with reduced renal function in females, but not in males.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-020-05616-0.

Characteristics and associated factors of acute kidney injury among adult dengue patients: A retrospective single-center study

Severe dengue cases have been increasingly reported in Thailand, and the under-reporting of acute kidney injury (AKI) in cases of dengue viral infection has become an obstacle in obtaining an accurate description of the true nature and epidemiology of AKI. Because AKI may lead to patient morbidity and mortality, an early diagnosis is important in preventing its onset in dengue patients. This study aimed to determine the prevalence, clinical and laboratory characteristics, and associated factors of AKI among adult dengue patients. This retrospective study reviewed admission data from the medical records of adult dengue patients admitted to the Bangkok Hospital for Tropical Diseases between January 2012 and November 2017 and stratified these patients into AKI and non-AKI groups using the Kidney Disease Improving Global Outcomes criteria (KDIGO). A total of 1,484 patients were included in the study, with 71 categorized into the AKI group. The prevalence of AKI was 4.8%. In the AKI group, the predominant age range was 18–40 years (71.8%), with a female to male ratio of 1:2.7. These patients showed significantly (P < 0.05) higher proportions of altered consciousness, dyspnea, low mean arterial blood pressure, high-grade fever, major bleeding, severe thrombocytopenia, hypoalbuminemia, severe transaminitis, coagulopathy, metabolic acidosis, rhabdomyolysis, proteinuria, hematuria, and pyuria. Our study established that older age, male sex, diabetes mellitus, obesity, severe dengue, and coexisting bacterial infection were significant associated factors for AKI in dengue by multivariate analysis. A total of 10 (14.1%) patients with AKI received dialysis, among which 9 (12.7%) patients from the AKI group died. Our findings suggest that an awareness of AKI, its early diagnosis, and evaluation of clinical and laboratory characteristics of dengue patients will help clinicians to initiate appropriate therapy for dengue-associated AKI.

Successful treatment of thrombotic microangiopathy associated with dengue infection: A case report and literature review

Dengue infection has been associated with multiple renal complications, including glomerulonephritis, acute tubular necrosis, tubulointerstitial nephritis, and thrombotic microangiopathy (TMA), this last one being a rare complication of dengue, with only a few reported cases. TMA associated with dengue can be explained by an alteration in the activity of the enzyme ADAMTS13, leading to thrombotic thrombocytopenic purpura; or it can be secondary to direct or indirect endothelial injury by the virus, which leads to hemolytic uremic syndrome. Here, we present a case of severe TMA, not related to ADAMTS13, which was clearly associated with dengue infection.

Time course of concurrent infection with dengue virus serotypes 2 and 4 detected in urine

Background

In hyperendemic areas, concurrent multiserotype dengue virus (DENV) infections commonly occur in both humans and in mosquito vectors. Previous studies have focused on single blood specimens.

Objectives

To illustrate and characterize the time course of mixed infection with DENV serotypes 2 (DENV2) and 4 (DENV4) in a single case.

Materials and methods

Plasma, saliva, and urine were collected from a patient diagnosed with dengue hemorrhagic fever grade II and secondary DENV infection on days 7, 18, and 31 of his illness. DENV RNA detection was performed using 2 DENV-specific reverse transcriptase-polymerase chain reaction protocols. Cloning and sequencing were performed to quantify the major and minor viral populations in dual-serotype-infected specimen(s). Genotypes of both DENV serotypes were characterized.

Results

DENV genome was detected in plasma and saliva only at the first time point (day 7 of illness), but in urine at both the first and second time points (days 7 and 18 of illness). DENV4 serotype was found in all DENV genome-positive specimens. DENV2 serotype was unexpectedly also detected in the first urine specimen. DENV4 as the major and DENV2 as the minor population. The DENV2 serotype was clustered in genotype Asian I and DENV4 serotype in genotype I.

Conclusion

To our knowledge, this is the first report of concurrent multiserotype DENV infection detected solely in urine. Prospective noninvasive investigations may determine the prevalence of this phenomenon. Clinical and public health implications of this finding need to be explored.

Dengue hemorrhagic fever and the kidney

Dengue virus infection (DVI)/dengue hemorrhagic fever (DHF) is a common febrile illness with a variety of severities. The mortality rate is high in dengue shock syndrome (DSS), caused by circulatory failure due to plasma leakage resulting in multi-organ failure. However, acute kidney injury (AKI) is rarely reported. In areas of endemic DVI, the prevalence of AKI due to DVI has been reported to be as high as 6.0 % in children with AKI, and 0.9 % in children with DVI who were admitted to a hospital. The mechanism of AKI in DVI is not clear. It may result from (a) direct injury as in other infectious diseases, (b) an indirect mechanism such as via the immune system, since DHF is an immunological disease, or (c) hypotensive DSS, leading in turn to reduced renal blood supply and renal failure. The mortality rates of DF/DHF, DSS and DHF/DSS-related AKI are <1 %, 12-44 %, and >60 %, respectively. Kidney involvement is not actually that rare, but is under-recognized and often only reported when microscopic hematuria, proteinuria, electrolyte imbalance, or even AKI is found. The prevalence of proteinuria and hematuria has been reported as high as 70-80 % in DVI. A correct diagnosis depends on basic investigations of kidney function such as urinalysis, serum creatinine and electrolytes. Although DVI-related renal involvement is treated supportively, it is still important to make an early diagnosis to prevent AKI and its complications, and if AKI does occur, dialysis may be required. Fortunately, in patients who recover, kidney function usually completely recovers as well.

Clinical profile of acute kidney injury in a pediatric intensive care unit from Southern India: A prospective observational study

Background:

Although the term acute renal failure was replaced by acute kidney injury (AKI) recently, there is a paucity of data on the incidence and profile of AKI in critically ill children from the developing world.

Objectives:

The objective of this study is to determine the incidence, etiology, short term outcome and predictors of fatality in critically ill children admitted to the pediatric intensive care unit (PICU) with AKI, aged 1 month to 13 years.

Materials and Methods:

In this prospective observational study, from June 2010 to March 2011, 215 children admitted to the PICU were screened for AKI, defined according to the AKI Network criteria. The patients with AKI were followed-up until discharge/death. Their clinical and biochemical data were recorded.

Results:

The incidence of AKI among 215 patients screened was 54 (25.1%). The common etiologies were infections, [34 (62.9%)], acute glomerulonephritis (7.6%), snake envenomation (5.7%), hemolytic uremic syndrome (3.8%) and congestive cardiac failures (3.8%). Among infections, pneumonia and septicemia constituted 26.5% each, meningoencephalitis accounted for 23.5%, and dengue, scrub typhus, tuberculosis and malaria constituted 9.3% of children with AKI. 27.8% of patients required dialysis. Overall mortality was 46.3%. On logistic regression analysis, requirement of mechanical ventilation was an independent predictor of fatality in AKI.

Conclusions:

Besides the high incidence of AKI in critically ill-children admitted to the PICU (25.1%), the condition was associated with adverse outcomes, including high mortality (46.3%) and need for dialysis (27.8%). Infections dominated the etiological profile. Requirement of mechanical ventilation predicted an adverse outcome in our patient population.

Microproteinuria during Opisthorchis viverrini infection: a biomarker for advanced renal and hepatobiliary pathologies from chronic opisthorchiasis

Approximately 680 million people are at risk of infection with Opisthorchis viverrini (OV) and Clonorchis sinensis, with an estimated 10 million infected with OV in Southeast Asia alone. While opisthorchiasis is associated with hepatobiliary pathologies, such as advanced periductal fibrosis (APF) and cholangiocarcinoma (CCA), animal models of OV infection show that immune-complex glomerulonephritis is an important renal pathology that develops simultaneously with hepatobiliary pathologies. A cardinal sign of immune-complex glomerulonephritis is the urinary excretion of immunoglobulin G (IgG) (microproteinuria). In community-based studies in OV endemic areas along the Chi River in northeastern Thailand, we observed that over half of the participants had urine IgG against a crude OV antigen extract (OV antigen). We also observed that elevated levels of urine IgG to OV antigen were not associated with the intensity of OV infection, but were likely the result of immune-complex glomerulonephritis as seen in animal models of OV infection. Moreover, we observed that urine IgG to OV antigen was excreted at concentrations 21 times higher in individuals with APF and 158 times higher in individuals with CCA than controls. We also observed that elevated urine IgG to OV antigen could identify APF+ and CCA+ individuals from non-cases. Finally, individuals with urine IgG to OV antigen had a greater risk of APF as determined by Odds Ratios (OR = 6.69; 95%CI: 2.87, 15.58) and a greater risk of CCA (OR = 71.13; 95%CI: 15.13, 334.0) than individuals with no detectable level of urine IgG to OV antigen. Herein, we show for the first time the extensive burden of renal pathology in OV endemic areas and that a urine biomarker could serve to estimate risk for both renal and hepatobiliary pathologies during OV infection, i.e., serve as a “syndromic biomarker” of the advanced pathologies from opisthorchiasis.

Approximately 680 million people risk infection with food-borne trematodes, including Opisthorchis viverrini (OV). Animal models show that significant kidney pathology results from OV infection as detected by antibodies in urine (microproteinuria). However, kidney pathology in humans infected with OV is often overlooked because it develops alongside more severe pathologies such as bile duct fibrosis and bile duct cancer. In Northeastern Thailand, the researchers observed that OV infected individuals had elevated levels of urine IgG against OV antigen that was not associated with the level of OV infection. The researchers observed that urine IgG to OV antigen was associated with bile duct fibrosis and bile duct cancer. Moreover, individuals with urine IgG to OV antigen also had elevated risk of bile duct fibrosis and bile duct cancer than individuals with no urine IgG to OV antigen. For the first time, OV infection has been shown to result in significant kidney disease in humans, which is also strongly associated with bile duct pathology. A urine-based assay that could indicate both renal and bile duct pathology from OV infection would be of profound benefit in Southeast Asia, especially in the resource-limited settings of the Mekong Basin region countries of Thailand, Laos and Cambodia.

Minimal change nephrotic syndrome in a patient with strongyloidiasis

Strongyloidiasis, a chronic infection caused by the intestinal parasite Strongyloides stercoralis, is prevalent in the Nansei Islands of Japan. Here, we report our findings on a case of strongyloidiasis complicated with steroid-resistant minimal change nephrotic syndrome in a 69-year-old male resident of Fukuoka Prefecture who had lived in Yakushima, one of the Nansei Islands, until age 15. In October 2006, he developed proteinuria and edema, and was diagnosed with minimal change nephrotic syndrome on the basis of the renal biopsy findings. Following treatment with prednisolone, the level of proteinuria decreased to 0.29 g/day by day 35. However, 5 days later (day 40), the patient developed persistent watery diarrhea and vomiting, leading to dehydration and malnutrition. Pneumonia and bacterial meningitis subsequently developed (day 146); filarial (infectious-type) and rhabditiform (noninfectious-type) S. stercoralis larvae were detected for the first time in the patient's sputum, gastric juice, feces, and urine. Although treatment with ivermectin was started immediately and the parasitosis responded to the treatment, the patient died of sepsis. Consequently, although strongyloidiasis is a rare infection except in endemic regions, it is essential to consider the possibility of this disease and begin treatment early for patients who have lived in endemic areas and who complain of unexplained diarrhea during steroid-induced or other immunosuppression.

A quantitative ultrastructural study of renal pathology in fatal Plasmodium falciparum malaria

OBJECTIVE

To use electron microscopy to examine the role of parasitized red blood cell (PRBC) sequestration in the pathogenesis of acute renal failure in severe falciparum malaria.

METHODS

Ultrastructural pathological examination of renal tissues from Southeast Asian adults (n = 63) who died from severe falciparum malaria. Qualitative and quantitative determination of the major pathological features of disease, including PRBC and leukocyte sequestration. Clinico-pathological correlation with the pre-mortem clinical picture and peripheral parasite count.

RESULTS

There was a high incidence of malaria-associated renal failure in this population (> 40%) and a correlation between this incidence, severe malarial anaemia and shock. Pathological features included PRBC sequestration in glomerular and tubulo-interstitial vessels, acute tubular damage and mild glomerular hypercellularity resulting from the accumulation of host monocytes within glomerular capillaries. No evidence for an immune complex mediated glomerulonephritis was found. There was a correlation between parasite sequestration in the kidney and pre-mortem renal failure, although overall levels of sequestration were relatively low. Levels of sequestration (Knob+ PRBC) were significantly higher in malaria-associated renal failure than in fatal cases without renal failure (P = 0.005).

CONCLUSION

Malaria-associated renal failure is a common and serious complication of severe Plasmodium falciparum malaria in this population, associated with acute tubular injury rather than glomerulonephritis, and linked to localization of host monocytes in the kidney as well as sequestration of PRBCs.

Malaria-induced renal damage: facts and myths

Malaria infections repeatedly have been reported to induce nephrotic syndrome and acute renal failure. Questions have been raised whether the association of a nephrotic syndrome with quartan malaria was only coincidental, and whether the acute renal failure was a specific or unspecific consequence of Plasmodium falciparum infection. This review attempts to answer questions about "chronic quartan malaria nephropathy" and "acute falciparum malaria nephropathy". The literature review was performed on all publications on kidney involvement in human and experimental malarial infections accessible in PubMed or available at the library of the London School of Hygiene and Tropical Medicine. The association of a nephrotic syndrome with quartan malaria was mostly described before 1975 in children and rarely in adult patients living in areas endemic for Plasmodium malariae. The pooled data on malaria-induced acute renal failure included children and adults acquiring falciparum malaria in endemic areas either as natives or as travellers from non-tropical countries. Non-immunes (not living in endemic areas) had a higher risk of developing acute renal failure than semi-immunes (living in endemic areas). Children with cerebral malaria had a higher rate and more severe course of acute renal failure than children with mild malaria. Today, there is no evidence of a dominant role of steroid-resistant and chronic "malarial glomerulopathies" in children with a nephrotic syndrome in Africa. Acute renal failure was a frequent and serious complication of falciparum malaria in non-immune adults. However, recently it has been reported more often in semi-immune African children with associated morbidity and mortality.

Acute renal dysfunction in salmonella gastroenteritis

GOALS

To determine the incidence of renal function deterioration in adult patients with Salmonella infection.

BACKGROUND

Renal impairment has been described during severe Salmonella infection and is mainly due to shock, dehydration, or rhabdomyolysis. However, it is unclear whether less severe Salmonella infection also has an impact on kidney function.

STUDY

We retrospectively reviewed over a 2-year period the data of all hospitalized adult patients with microbiologically proven gastrointestinal infection. Different biologic parameters were compared between patients infected with Salmonella and patients with other gastrointestinal infections.

RESULTS

One hundred and seven patients with positive stool cultures were identified; 44 of them had proven Salmonella infection. Renal dysfunction, defined as an increase in serum creatinine above 1.5 mg/dL in men and above 1.3 mg/dL in women, was observed in 16 (36%) patients infected by Salmonella but only in 3 (5%) comparators (P<0.0001). Hydration status and creatine kinase levels were not different in patients affected by Salmonella as compared with other pathogens. Kidney function recovered in all but 1 patient.

CONCLUSIONS

Salmonella gastroenteritis in adults is frequently accompanied by renal dysfunction that is caused by mechanisms other than dehydration or rhabdomyolysis.

Nephrotoxicity associated with exposure to plant toxins, with particular reference to Africa

Acute renal failure is a frequent cause of morbidity and mortality in the hospitalized population worldwide. In Africa, apart from hemodynamic causes and infections, herbal remedies contribute to both morbidity and mortality, although these causes often go unrecognized. This paper reviews reports of herbal remedies that have been shown to result in nephrotoxicity. The indications for use of the remedies, signs and symptoms in poisoned patients, and the methods used to detect toxic compounds in plant specimens or in biological fluids are covered.

Pathobiology of opisthorchiasis: an update

Opisthorchis viverrini infection is associated with several hepatobiliary diseases including cholangitis, obstructive jaundice, hepatomegaly, cholecystitis and cholelithiasis. Pathological consequences of O. viverrini infection occur mainly in the liver, extrahepatic bile ducts, gall bladder and kidney. These pathologies have been described in both humans and experimental animals. Moreover, both experimental and epidemiological evidence strongly implicate the liver fluke infection in the etiology of cholangiocarcinoma--the bile duct cancer. This review summarizes the pathology of opisthorchiasis from literature mainly published between 1970 and the present time and, particularly, emphasizes on current concept in pathogenesis of the disease. The theme is to highlight the new era of pathogenetic study of opisthorchiasis especially on host-parasite interaction and host immune/inflammatory responses leading to tissue damage.