The kidney in leptospirosis

Exudative glomerulonephritis associated with acute leptospirosis in dogs

In the past 20 years in Switzerland, dogs with suspect acute leptospirosis frequently showed severe glomerular changes that had not been previously reported. These features were characterized by abundant extravasated erythrocytes and fewer neutrophils accompanied by marked fibrin exudation into the urinary space that was interpreted as an exudative glomerulonephritis (GN). This retrospective study describes this significant glomerular pathological change and investigates the association with leptospirosis. Tissues from 50 dogs with exudative GN, retrieved from 2 pathology archives in Switzerland were reviewed using hematoxylin and eosin, periodic acid-Schiff, phosphotungstic acid-hematoxylin, and Warthin and Starry stains. Clinical and postmortem data were collected for each case. Immunohistochemistry (IHC) and/or polymerase chain reactions were used as confirmatory tests for leptospirosis. While all 50 cases had clinical and pathological features supporting a diagnosis of leptospirosis, 37 cases were confirmed for the disease. Using a LipL32 antibody in addition to the OMV2177 antibody raised against the lipopolysaccharide of Leptospira interrogans serovar Copenhageni increased the detection rate of Leptospira by IHC in exudative GN from 24% to 62%. Signalment, seasonality, clinical signs, blood results, and pathological changes in dogs with exudative GN were similar to those reported for dogs without GN and confirmed infection by Leptospira spp.. Exudative GN was common among Swiss dogs with leptospirosis where it caused acute severe disease. Leptospirosis should be considered as a cause of this new pathologic feature by the pathologist. The pathogenesis remains unclear, but involvement of a geographic-specific serovar with unique virulence factors is suspected and warrants further investigation.

Weil's Disease in an HIV-Infected Patient: A Case Report and Literature Review

Weil's disease, an icterohemorrhagic infection, is the most severe and fatal form of leptospirosis and is characterized by jaundice, renal dysfunction, and hemorrhagic predisposition. Weil's disease with HIV infection has rarely been reported. A 68-year-old male with HIV infection presented to our hospital with fever and dyspnea that progressed to severe hemoptysis and systemic multiple organ failure, necessitating a tracheal intubation ventilator. A diagnosis of Weil's disease was made after Leptospira interrogans was identified via metagenomic next-generation sequencing (mNGS) in bronchoalveolar lavage fluid (BALF). After immediately receiving supportive therapy and targeted antimicrobial agents, the patient achieved complete recovery upon discharge. The co-infection of HIV infection and leptospirosis resulting in systemic multi-organ failure is rare, but awareness should be raised of the differential diagnosis. mNGS can help identify pathogens and facilitate the use of targeted and efficacious antimicrobial therapy in unusual clinical environments.

Clinical characteristics and outcomes of patients with leptospirosis complicated with acute pancreatitis: a systematic review

OBJECTIVES

Acute pancreatitis (AP) is a severe complication of leptospirosis. This review focuses on the current evidence of AP in patients with leptospirosis.

METHODS

Data on clinical characteristics, biochemical parameters, diagnosis, complications, critical care, fluid management, operative management, and outcomes were analyzed. This study was registered in PROSPERO (CRD42022360802).

RESULTS

We included 35 individual case reports and 4 case series involving 79 patients. Sex was reported for 48 (60.7%) patients; 38 (48.1%) were male and 10 (12.6%) were female. The patients' mean age was 45.13 (15-83 years). Acute kidney injury, thrombocytopenia, hypotension, and liver injury were the most common complications reported. Complete recovery was reported for 36 (45.5%) patients. Biochemical and radiological recovery was reported for 10 (12.6%) and 9 (11.3%) patients, respectively. Death was reported in 18 (22.7%) patients.

CONCLUSION

A high degree of clinical suspicion and different modalities of investigations are essential in the diagnosis of AP in leptospirosis. AP can be easily missed in leptospirosis because both conditions share similar clinical presentations and complications. Because of the high prevalence of acute kidney injury, judicious fluid management and close monitoring are mandatory.

Importance of KIM-1 and MCP-1 in Determining the Leptospirosis-Associated AKI: A Sri Lankan Study

BACKGROUND

Acute kidney injury (AKI) is one of most prevalent and serious complications of leptospirosis, a prevalent zoonotic disease in tropical countries. Prompt diagnosis of the leptospirosis-associated AKI is a challenge as there are no proper diagnostic tools that can identify patients in the early stage. Kidney injury molecule-1 (KIM-1) and monocyte chemoattractant protein-1 (MCP-1) are widely used novel AKI biomarkers that are studied in various disease conditions with AKI, but not in leptospirosis. Thus, this study is aimed at seeking the importance of KIM-1 and MCP-1 in determining the leptospirosis-associated AKI.

METHODS

Leptospirosis-suspected patients who were admitted to medical wards of two selected hospitals in the Western province of Sri Lanka were recruited. Leptospirosis was confirmed by three diagnostic tests: PCR, MAT, and culture, and the status of AKI was determined by Kidney Disease Improving Global Outcomes (KDIGO) criteria.

RESULTS

Of 170 leptospirosis-suspected patients, 79 were leptospirosis confirmed, and among them, 24.05% of patients were diagnosed to have AKI according to KDIGO criteria. Median serum KIM-1 (p < 0.0001), urine KIM-1 (0.0053), serum MCP-1 (0.0080), and urine MCP-1 (0.0019) levels in those developing AKI were significantly higher than in patients not developing AKI. The biomarker levels associated with leptospirosis AKI had AUC-ROC of 0.8565, 0.7292, 0.7024, and 0.7282 for serum KIM-1, urine KIM-1, serum MCP-1, and urine MCP-1, respectively.

CONCLUSION

This study revealed serum KIM-1 as a promising marker for leptospirosis-associated AKI among the tested biomarkers. Thus, further validation is recommended with a larger study group.

Histopathology of the kidney and seroprevalence of leptospirosis in wild rats in Baghdad Province, Iraq

Background and Aim: Leptospirosis, caused by pathogenic leptospires, is a globally emerging infectious disease affecting both humans and animals, which act as reservoirs, with large outbreaks worldwide. The role of rats in dispersing leptospirosis was never investigated in Iraq. Because of the seriousness of the disease and the scarce data regarding this disease in Iraq, this study determines the incidence of leptospirosis in rats and its renal histopathological profile. Materials and Methods: Of 211 captured rats, 82 apparently healthy rats were included in this study. After euthanatizing, 3-5-ml blood was collected by cardiac puncture. Approximately 0.5 cm3 of the kidney was collected for routine histopathology and stained using hematoxylin and eosin (H&E) and Warthin–Starry (WS) stains. Blood smears were prepared and stained with the WS stain. Results: All rats (100%) with different age groups were immunoglobulin G (IgG)-positive, and 90.24% of them had the IgG against leptospiral antigens in kidney tissues. The juvenile age group had higher IgG levels than other age groups. Considering sex, no significant differences in the overall results were observed. Serum concentrations of blood urea nitrogen and creatinine showed significant increments in the sub-adult and adult IgG- positive groups compared with the IgG-negative groups. No significant alterations were observed in the juvenile group. Using WS stains, 13 and 1 blood smears and 0 and 8 kidney tissues were positive for leptospires in the sub-adult and adult groups, respectively. Microscopical findings of the renal cortex and medulla in the sub-adult IgG-positive group showed hemorrhage, glomerular deterioration, tubular cell degeneration and necrosis with cast formation, periarterial edema, and focal hemorrhage with congestion of peritubular arteries. The adult IgG-positive group revealed deterioration similar to that in the sub-adult group and tended to be chronic. No leptospires were observed using H&E staining. Conclusion: IgG-positive carrier rats refer to previously exposed or infected rats. Understanding the risk of transmitting the disease to human and animals through a carrier rat's urine is highly predicted and possible mitigation of zoonotic transmission.

Acute kidney injury due to Leptospira interrogans in 4 foals and use of renal replacement therapy with intermittent hemodiafiltration in 1 foal

Four 2‐month‐old foals were presented to an equine hospital with acute kidney injury caused by Leptospira interrogans infection. Clinical signs were nonspecific and included lethargy, fever, and unwillingness to nurse. The most important hematologic and clinicopathologic findings were azotemia, anemia, thrombocytopenia, hyponatremia, and hypochloremia. The diagnosis was based on urinary real‐time PCR, serology using a microscopic agglutination test, or both. The most important serovars involved were L. interrogans serogroup australis serovar Bratislava and Australis. Treatment consisted of IV fluid therapy and antimicrobial treatment. Renal replacement therapy with hemodiafiltration was performed in 1 of the foals. All foals survived to discharge. This report highlights the importance of early diagnosis and treatment in foals with acute kidney injury caused by L. interrogans infection.

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.

Leptospirosis: Report from the task force on tropical diseases by the World Federation of Societies of Intensive and Critical Care Medicine

Leptospirosis is a zoonosis caused by a gram negative aerobic spirochete of the genus Leptospira. It is acquired by contact with urine or reproductive fluids from infected animals, or by inoculation from contaminated water or soil. The disease has a global distribution, mainly in tropical and subtropical regions that have a humid, rainy climate and is also common in travelers returning from these regions. Clinical suspicion is critical for the diagnosis and it should be included in the differential diagnosis of any patient with a febrile hepatorenal syndrome in, or returning from endemic regions. The leptospiremic phase occurs early and thereafter there is an immunologic phase in which the most severe form, Weil's disease, occurs. In the latter, multiple organ dysfunction predominates. The appropriate diagnostic test depends on the stage of the disease and consists of direct and indirect detection methods and cultures. Severely ill patients need to be monitored in an ICU with appropriate anti-bacterial agents and early, aggressive and effective organ support. Antibiotic therapy consists of penicillins, macrolides or third generation cephalosporins.

Lp25 membrane protein from pathogenic Leptospira spp. is associated with rhabdomyolysis and oliguric acute kidney injury in a guinea pig model of leptospirosis

Acute kidney injury (AKI) from leptospirosis is frequently nonoliguric with hypo- or normokalemia. Higher serum potassium levels are observed in non-survivor patients and may have been caused by more severe AKI, metabolic disarrangement, or rhabdomyolysis. An association between the creatine phosphokinase (CPK) level and maximum serum creatinine level has been observed in these patients, which suggests that rhabdomyolysis contributes to severe AKI and hyperkalemia. LipL32 and Lp25 are conserved proteins in pathogenic strains of Leptospira spp., but these proteins have no known function. This study evaluated the effect of these proteins on renal function in guinea pigs. Lp25 is an outer membrane protein that appears responsible for the development of oliguric AKI associated with hyperkalemia induced by rhabdomyolysis (e.g., elevated CPK, uric acid and serum phosphate). This study is the first characterization of a leptospiral outer membrane protein that is associated with severe manifestations of leptospirosis. Therapeutic methods to attenuate this protein and inhibit rhabdomyolysis-induced AKI could protect animals and patients from severe forms of this disease and decrease mortality.

Acute Kidney Injury Recognition in Low- and Middle-Income Countries

Acute kidney injury (AKI) is increasingly common around the world. Because of the low availability of effective therapies and resource limitations, early preventive and therapeutic measures are essential to decrease morbidity, mortality, and cost. Timely recognition and diagnosis of AKI requires a heightened degree of suspicion in the appropriate clinical and environmental context. In low- and middle-income countries (LMICs), early detection is impaired by limited resources and low awareness. In this article, we report the consensus recommendations of the 18th Acute Dialysis Quality Initiative meeting in Hyderabad, India, on how to improve recognition of AKI. We expect these recommendations will lead to an earlier and more accurate diagnosis of AKI, and improved research to promote a better understanding of the epidemiology, etiology, and histopathology of AKI in LMICs.

Acute kidney injury due to tropical infectious diseases and animal venoms: a tale of 2 continents

South and Southeast Asia and Latin American together comprise 46 countries and are home to approximately 40% of the world population. The sociopolitical and economic heterogeneity, tropical climate, and malady transitions characteristic of the region strongly influence disease behavior and health care delivery. Acute kidney injury epidemiology mirrors these inequalities. In addition to hospital-acquired acute kidney injury in tertiary care centers, these countries face a large preventable burden of community-acquired acute kidney injury secondary to tropical infectious diseases or animal venoms, affecting previously healthy young individuals. This article reviews the epidemiology, clinical picture, prevention, risk factors, and pathophysiology of acute kidney injury associated with tropical diseases (malaria, dengue, leptospirosis, scrub typhus, and yellow fever) and animal venom (snakes, bees, caterpillars, spiders, and scorpions) in tropical regions of Asia and Latin America, and discusses the potential future challenges due to emerging issues.

Leptospira seropositivity as a risk factor for Mesoamerican Nephropathy

BACKGROUND

Leptospirosis is postulated as a possible cause of Mesoamerican Nephropathy (MeN) in Central American workers.

OBJECTIVES

Investigate job-specific Leptospira seroprevalence and its association with kidney disease biomarkers.

METHODS

In 282 sugarcane workers, 47 sugarcane applicants and 160 workers in other industries, we measured anti-leptospiral antibodies, serum creatinine, and urinary injury biomarkers, including neutrophil gelatinase-associated lipocalin (NGAL), interleukin-18 (IL-18), and N-acetyl-D-glucosaminidase (NAG).

RESULTS

Leptospira seroprevalence differed among job categories and was highest among sugarcane cutters (59%). Seropositive sugarcane workers had higher NGAL concentrations (relative mean: 1.28; 95% CI: 0.94-1.75) compared to those who were seronegative, with similar findings among field and non-field workers.

CONCLUSIONS

Leptospira seroprevalence varied by job category. There was some indication that seropositivity was associated with elevated biomarker levels, but results were inconsistent. Additional studies may help establish whether Leptospira infection plays any role in MeN among Central American workers.

Sustained Tubulointerstitial Inflammation in Kidney with Severe Leptospirosis

Leptospirosis is frequently associated with acute kidney injury. Some survivors are known to progress to chronic kidney disease due to sustained tubulointerstitial inflammation. We present a case of severe leptospirosis with acute renal failure. Although antibiotic therapy resolved the infection, moderate renal dysfunction remained. A renal biopsy demonstrated marked inflammatory infiltration in the tubules and interstitium. Many of the inflammatory cells were CD68-positive monocytes/macrophages, predominantly M1 phenotype. An intermediate dose of oral corticosteroids normalized the patient's serum creatinine levels. We suggest that corticosteroid therapy may be a therapeutic option for some patients with sustained tubulointerstitial nephritis who survive severe leptospirosis.

Pediatric Fulminant Leptospirosis Complicated by Pericardial Tamponade, Macrophage Activation Syndrome and Sclerosing Cholangitis

BACKGROUND

Leptospirosis is a zoonotic infectious disease caused by pathogenic spirochetes of the genus Leptospira. Although it is usually asymptomatic and self-limited, severe potentially fatal illness accompanied by multi-organ failure may occur.

CASE REPORT

Here we report an unusual case of severe leptospirosis successfully treated with continuous venovenous hemofiltration (CVVHF) and therapeutic plasma exchange (TPE). The patient presented with pericardial tamponade, renal failure and macrophage activation syndrome, and later suffered prolonged jaundice and sclerosing cholangitis during hospitalization in the pediatric intensive care unit (PICU). To the best of our knowledge, sclerosing cholangitis due to leptospirosis has not been reported in the literature.

CONCLUSION

Leptospirosis should be kept in mind in the differential diagnosis of sepsis and septic shock with fever, thrombocytopenia, jaundice and renal failure. TPE and CVVHF should start early after the diagnosis of leptospirosis with multiorgan failure.

A Rare Presentation of Leptospirosis

Leptospirosis has a wide spectrum of clinical manifestations. Acute renal failure, an important complication, generally involves interstitial and tubular damage. We describe the case of a 42-year-old man who was admitted with fever, back pain and periorbital oedema. He had hypertension, thrombocytopenia, acute renal failure, hypoalbuminaemia, hypertriglyceridaemia and proteinuria >4.00 g/l. The renal biopsy showed mesangioproliferative glomerulonephritis. Due to the epidemiological context and clinical picture, ceftriaxone was started with rapid clinical improvement. Blood PCR for leptospira came back positive. The presentation of leptospirosis as nephrotic syndrome is rare and this diagnosis should be considered before performing a renal biopsy.

LEARNING POINTS

Leptospirosis is a zoonosis with a wide spectrum of clinical manifestations including acute renal failure, which is an important complication.Leptospirosis should be considered in a patient with nephrotic syndrome and acute renal failure if the epidemiological context is favourable.Leptospirosis is one of the causes of nephrotic syndrome where a renal biopsy is not indicated.

Infectious Diseases and the Kidney in Children

The kidney is involved in a wide range of bacterial, viral, fungal, and parasitic diseases. In most systemic infections, renal involvement is a minor component of the illness, but in some, renal failure may be the presenting feature and the major problem in management. Although individual infectious processes may have a predilection to involve the renal vasculature, glomeruli, interstitium, or collecting systems, a purely anatomic approach to the classification of infectious diseases affecting the kidney is rarely helpful because most infections may involve several different aspects of renal function. In this chapter, a microbiological classification of the organisms affecting the kidney is adopted. Although they are important causes of renal dysfunction in infectious diseases, urinary tract infections and hemolytic uremic syndrome (HUS) are not discussed in detail because they are considered separately in chapters XX and XX, respectively.

Successful treatment of severe hypokalemia in a dog with acute kidney injury caused by leptospirosis

OBJECTIVE

To report the case management of a patient with severe hypokalemia resulting in cardiopulmonary arrest caused by infection with leptospirosis.

CASE SUMMARY

A 3-year-old intact female Dachshund presented for polyuria, polydipsia, and refractory hypokalemia, which progressed to flaccid paralysis and cardiorespiratory arrest. Following successful resuscitation, the dog was apneic and managed with mechanical ventilation while volume status and electrolytes were corrected. The dog showed rapid improvement allowing for weaning from the ventilator within the first day. The dog was identified as having leptospirosis causing severe kaliuresis (fractional excretion of potassium 31%). Following discharge from hospital, the dog was managed with doxycycline, oral potassium supplementation, and spironolactone and made a full clinical recovery.

NEW OR UNIQUE INFORMATION PROVIDED

This report identifies an unusually severe presentation of leptospirosis in a dog from a region where the disease is not considered common, which was successfully treated despite cardiopulmonary arrest on initial presentation.

Low serum total nitrite and nitrate levels in severe leptospirosis

Background

The relationship between inducible nitric oxide synthatase activity and disease severity in leptospirosis is unclear. Nitric oxide is converted to nitrites and nitrates, thus nitrite and nitrate levels (NO^x) in serum are considered surrogate markers for nitric oxide. NO_x are excreted through the kidneys, and elimination is diminished in renal impairment. We assessed the correlation of NO_x with disease severity in patients with leptospirosis, compared with healthy controls and non-leptospirosis fever patients.

Methods

All patients admitted over a two-month period to the National Hospital, Colombo, Sri Lanka with a clinical picture suggestive of leptospirosis were included. Leptospirosis was confirmed by the microscopic agglutination test (titre≥400). Severe leptospirosis was defined by the presence of two or more of the following criteria: jaundice (bilirubin> 51.3 μmol/l), oliguria (urine output < 400 ml/day), serum creatinine> 133 μmol/l or blood urea > 25.5 mmol/l, or the presence of organ dysfunction. Non-leptospirosis fever patients and healthy volunteers were used as control groups. NO_x levels were measured using a modified Griess reaction.

Results

Forty patients were confirmed as having leptospirosis and 26 of them had severe disease. NO_x levels were significantly higher in confirmed leptospirosis patients compared to healthy controls, MAT equivocal patients and non-leptospirosis fever patients (p<0.001). NO_x concentrations were also significantly higher in patients with severe compared to mild leptospirosis (p<0.001). Once NO_x levels were corrected for renal function, by using the ratio NO_x/creatinine, NO_x levels were actually significantly lower in patients with severe disease compared to other patients, and values were similar to those of healthy controls.

Conclusions

We postulate that high NOx levels may be protective against severe leptospirosis, and that finding low NOx levels (when corrected for renal function) in patients with leptospirosis may predict the development of severe disease and organ dysfunction.

Severe leptospirosis with multiple organ failure successfully treated by plasma exchange and high-volume hemofiltration

Background. Leptospirosis is a spirochetal zoonosis with complex clinical features including renal and liver failure. Case report. We report the case of a Swiss fisherman presenting with leptospirosis. After initial improvement, refractory septic shock and severe liver and kidney failure developed. The expected mortality was estimated at 90% with clinical scores. The patient underwent plasma exchanges and high-volume hemofiltration (HVHF) with complete recovery of hepatic and kidney functions. Discussion. Plasma exchanges and HVHF may confer survival benefit on patients with severe leptospirosis, refractory septic shock, and multiple-organ failure.

RIFLE and Acute Kidney Injury Network classifications predict mortality in leptospirosis-associated acute kidney injury

AIM

Acute kidney injury (AKI) is a common complication in leptospirosis. The aim of this study is to investigate the association between RIFLE and AKIN classifications with mortality in leptospirosis-associated AKI.

METHODS

A retrospective study was conducted in patients with leptospirosis admitted to tertiary hospitals in Brazil. The association between RIFLE and AKIN classifications with mortality was investigated. Univariate and multivariate analysis was performed to investigate risk factors for death.

RESULTS

A total of 287 patients were included, with an average age of 37 ± 16 years, and 80.8% were male. Overall mortality was 13%. There was a significant association between these classifications and death. Among non-survivors, 86% were in the class 'failure' and AKIN 3. Increased mortality was observed according to the worse classifications: 'risk' (R; 2%), 'injury' (I; 8%) and 'failure' (F; 23%), as well as in AKIN 1 (2%), AKIN 2 (8%) and AKIN 3 (23%) (P < 0.0001). The worst classifications were significantly associated with death: RIFLE F (odds ratio = 11.6, P = 0.018) and AKIN 3 (odds ratio = 12.8, P = 0.013). Receiver-operator curve for patients with AKI showed high areas under the curve (0.71, 95% confidence interval = 0.67-0.74) for both RIFLE and AKIN classifications in determining the sensitivity for mortality.

CONCLUSION

There is a significant association between RIFLE and AKIN classifications with mortality in patients with leptospirosis. Initiation of dialysis in patients with RIFLE F and AKIN 3 should always be considered.

Acute kidney injury in human leptospirosis: an immunohistochemical study with pathophysiological correlation

Tubulointerstitial nephritis is a common clinicopathological finding in leptospirosis. Clinically, nonoliguric acute kidney injury (AKI), hypokalemia, sodium, and magnesium wasting frequently occur in leptospirosis. The exact mechanisms of renal involvement remain largely unclear. Immunohistochemistry to detect expression of the endogenous sodium/hydrogen exchanger isoform 3 (NHE 3), aquaporin 1 and 2, alpha-Na(+)K(+)ATPase, and sodium-potassium-chloride cotransporter in its NKCC2 isoform was performed on kidneys removed during autopsy of human leptospirosis cases and kidneys removed during autopsy of human non-leptospirosis cases with and without evidence of acute tubular necrosis (ATN). A decrease in NHE 3, aquaporin 1, and alpha-Na(+)K(+)ATPase expression occurred in proximal convoluted tubule cells. Expression of aquaporin 1 was preserved along the descending thin limb of the loop of Henle in the outer medulla. alpha-Na(+)K(+)ATpase expression was essentially preserved in the distal tubules, i.e., the thick ascending limb of the loop of Henle, macula densa, and distal convoluted tubule. Aquaporin 2 expression in the collecting tubules was enhanced compared to those of non-leptospirotic kidneys. NKCC2 cotransport isoform was expressed in the thick ascending limb of the loop of Henle and was essentially preserved in leptospirotic kidneys. Primary injury of the proximal convoluted tubules is regarded as the hallmark of the kidney in leptospirosis. Sodium and water transport are particularly affected with increased distal potassium excretion, hypokalemia, and polyuria. Enhanced expression of aquaporin 2 in medullary collecting tubules is probably an attempt to retain water during the nonoliguric phase of renal failure.