Leptospiral nephropathy

A Comparative Study of Community-acquired Acute Kidney Injury and Hospital-acquired Acute Kidney Injury from a Tertiary Care Hospital in North India

BACKGROUND

In this observational study, clinical characteristics, etiologies, and outcomes of patients admitted to the hospital with community-acquired acute kidney injury (CAAKI) have been compared in contrast to those who hospital-acquired Acute Kidney Injury (HAAKI).

METHODS

This was a prospective study of adults aged 18 years or above diagnosed with acute kidney injury (AKI) over a period of 17 months at a tertiary care hospital.

RESULTS

230 patients had AKI with the mean age of the study population being 45.33 ± 12.68 years. 178 (77.4%) patients were enrolled from medical unit, 25 (10.7%) from surgical unit, and 27 (11.7%) from obstetrical unit. The observed incidence of AKI was 15/1000 admissions. About 58.2% had CAAKI and 96 (43.7%) had HAAKI. Out of 230 patients, 170 (73.9%) patients were male and 60 (26.1%) were female. Sepsis was the most common (52.1%) etiology of AKI among the medical cases. Urosepsis, scrub typhus, and pneumonia were the most common causes of AKI. Sixty percent of AKI was Kidney Disease Improving Global Outcomes Stage 1 or 2 and 40% was in Stage 3. Oliguria was seen in 56.5%, hyperkalemia in 34.7%, fluid overload in 6.1%, and metabolic acidosis in 22.6%. The majority of patients had multiple organ involvement (52.1%) at the time of enrollment. About 116 (50.4%) had lung injury requiring mechanical ventilation and 95 (41.3%) were on inotropes. Mortality occurred in 19.5%. Anemia, the use of vasopressor drugs, and the need for intensive care support were independent predictive factors for mortality.

CONCLUSION

AKI was common in hospitalized patients and leads to significant inhospital mortality. AKI is largely a CAAKI, and the lesser extent is due to HAAKI. Many causes are potentially preventable. Early fluid resuscitation, effective antibiotics, appropriate antidotes, and timely referral of established AKI patients to centers with dialysis facilities can improve AKI outcomes.

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.

Thai-Lepto-on-admission probability (THAI-LEPTO) score as an early tool for initial diagnosis of leptospirosis: Result from Thai-Lepto AKI study group

Background

Leptospirosis is one of the most important zoonosis in the tropics. Currently, specific laboratory diagnostic test for leptospirosis such as polymerase chain reaction (PCR) or direct culture cannot be applied at the primary care setting especially in the resource- limited countries. Therefore, clinical presentation and laboratory examination are still the primary diagnostic tools for leptospirosis.

Objectives

To detect clinical factors for predicting leptospirosis in suspected cases, and to create a clinical prediction score (THAI-LEPTO) that is practical and easy to use in general practice while awaiting laboratory results.

Materials and methods

We performed a prospective multicenter study with a development and a validation cohort of patients presenting with clinical suspicion of leptospirosis as per the WHO clinical criteria. The development cohort was conducted at 11 centers in 8 provinces around Thailand. The validation cohort was conducted at 4 centers in 1 province from the Northeastern part of Thailand. Leptospirosis confirmed cases were defined if any one of the tests were positive: microscopic agglutination test, direct culture, or PCR technique. Multivariable logistic regression was used to identify predictors of leptospirosis. The clinical prediction score was derived from the regression coefficients (original) or from the odds ratio values (simplified). We used receiver operating characteristic (ROC) curve analysis to evaluate the diagnostic ability of our score and to find the optimal cutoff values of the score. We used a validation cohort to evaluate the accuracy of our methods.

Results

In the development cohort, we enrolled 221 leptospirosis suspected cases and analyzed 211. Among those, 105 (50%) were leptospirosis confirmed cases. In logistic regression adjusted for age, gender, day of fever, and one clinical factor at a time, leptospirosis group had more hypotension OR = 2.76 (95% CI 1.07–7.10), jaundice OR = 3.40 (95%CI 1.48–8.44), muscle pain OR = 2.12 (95%CI 1.06–4.26), acute kidney injury (AKI) OR = 2.90 (95%CI 1.31–6.15), low hemoglobin OR = 3.48 (95%CI 1.72–7.04), and hypokalemia with hyponatremia OR = 3.56 (95%CI 1.17–10.84) than non-leptospirosis group. The abovementioned factors along with neutrophilia and pulmonary opacity were used in the development of the score. The simplified score with 7 variables was the summation of the odds ratio values as follows: hypotension 3, jaundice 2, muscle pain 2, AKI 1.5, low hemoglobin 3, hypokalemia with hyponatremia 3, and neutrophilia 1. The score showed the highest discriminatory power with area under the curve (AUC) 0.82 (95%CI 0.67–0.97) on fever day 3–4. In the validation cohort we enrolled 96 leptospirosis suspected cases and analyzed 92. Of those, 69 (75%) were leptospirosis confirmed cases. The performance of the simplified score with 7 variables at a cutoff of 4 was AUC 0.78 (95%CI 0.68–0.89); sensitivity 73.5; specificity 73.7; positive predictive value 87.8; negative predictive value 58.3.

Conclusions

THAI-LEPTO score is a newly developed diagnostic tool for early presumptive diagnosis of leptospirosis in patients presenting with severe clinical suspicion of the disease. The score can easily be applied at the point of care while awaiting confirmatory laboratory results. Each predictor used has been supported by evidence of clinical and pathophysiological correlation.

Leptospirosis is an important zoonosis in the tropics. However, there is still a major barrier of early diagnosis of leptospirosis due to a lack of specific and sensitive testing. Moreover, in resource-limited countries with small budgets, a simple and cheap diagnostic test is essential for the diagnosis of leptospirosis. The THAI-LEPTO score has been developed and validated based on the relevant clinical history and related laboratory test. This score will help the physician in early diagnosis and prompt treatment leptospirosis as a point of care test. Finally, we aim that this scoring system can be one of the key parts of diagnostic algorithm and improve leptospirosis patients’ outcome.

Tropical Diseases Nephropathy - An Underemphasized Comorbidity

The tropical areas are a home to a number of diseases because of the hot & humid climate, and lack of health care facilities. Tropical Nephropathies are a major health problem and a matter of great concern. The main causes of kidney injury in tropics are due to bacterial, viral or parasitic infections like malaria, dengue, leptospirosis, scrub typhus, acute gastroenteritis, tuberculosis, leprosy and toxic envenomations like snake bite. Renal injury associated with tropical infections has a wide spectrum of presentations ranging from acute kidney injury to chronic kidney disease. Renal involvement in infectious diseases by one or other mechanism is a definite cause of increased morbidity and mortality. Proper understanding of these diseases, early diagnosis, patient education and improved health care facilities will lead to a better outcome and improved survival. This article reviews the various tropical infections causing kidney injury including pathophysiology and line of management.

Long term outcome of acute kidney injury due to leptospirosis? A longitudinal study in Sri Lanka

BACKGROUND

Leptospirosis is an important zoonotic disease of variable severity and is a common cause of acute kidney injury (AKI) in tropics. However the knowledge on long term renal outcome in leptospirosis is scarce. This study aims to assess the long-term renal outcome of AKI caused by leptospirosis.

FINDINGS

Hospital records of patients who had developed AKI following leptospirosis (Serologically confirmed) presented to two Teaching Hospitals in Kandy district over 3 years from 2007 were studied. A total of 44 patients were included and they had been followed up at least for one year in out patient clinics with regular assessment including renal status. Renal histology was studied in two patients. The primary outcome measure was normalization of renal function at one year. Of the 44 patients, 31 were in the risk and injury stage (Group 1), and the rest of them were in the failure stage (Group 2) under RIFLE criteria. Of group 2 patients, 11 had abnormal renal functions on discharge. Their mean serum creatinine and GFR values on discharge were 392 mmol/l and 20 ml/min/1.73 m2. Other two patients had full renal recovery whilst in the hospital. Nine in the group 2 required renal replacement therapy by means of peritoneal dialysis, intermittent haemodialysis or haemofiltration. Seventeen out of the total had persistently abnormal renal functions on discharge. Of them 13 recovered their renal functions to normal. Four patients (9%) who belonged to group 2, had persistently abnormal renal functions after first year compatible with stage 3 chronic kidney disease (CKD). Renal histology of two patients showed tubulointerstitial lymphocyte infiltrate, tubular atrophy and interstitial fibrosis.

CONCLUSION

The long term renal outcome of AKI following leptospirosis is satisfactory as only 9% of patients had abnormal renal functions compatible with early stage of CKD. Even among them, advanced CKD or dialysis dependency had not been observed.

Leptospirosis in vellore: a clinical and serological study

Leptospirosis is a severe spirochetal zoonosis in the world. It is considered an occupational disease of persons engaged in agriculture, sewage works, forestry, and animal slaughtering. A study was conducted with an objective of assessing the seroprevalence of leptospirosis in and around Vellore district, Tamil Nadu. The study was based on the signs and symptoms of the patients reporting fever in Vellore Municipal Clinic (Urban Malarial Scheme). Blood samples were collected from 129 patients. Animal studies were conducted from 24 rodents captured form the market place of the Vellore municipality. In the ZET (Zonal Entomological Team, Vellore) Laboratory the sera were examined by macroscopic slide agglutination test (MSAT). In the MAST, totally 10 positive leptospiral cases from human beings and 10 positive leptospiral cases from rats (Rattus rattus and Rattus norvegicus) were found out. Then both positive cases of leptospiral vials were labeled, sealed, and sent to the Leptospirosis Research Laboratory, Madhavaram, Chennai, for further serovars examination. Among the various serovars identified autumnalis was more prevalent. Our findings showed that the age groups between 15 and 55 years showed more susceptibility. Particularly the adults were more infected. The majority of seropositive individuals in the cases had only subclinical infection. Rodents were abundant and contributed to enzootic and endemic prevalence of leptospirosis.

Leptospirosis and renal failure: a case series

Leptospirosis is a ubiquitous and potentially fatal zoonosis with protean manifestations. Human infection commonly occurs through contact with contaminated water or soil. In developed countries, leisure or household activities are increasingly associated with the disease. Within few months, we encountered five unrelated and autochthonous cases of severe leptospirosis, three of them requiring interim dialysis. In this case series, we present their clinical course. Furthermore, we provide an overview on the spectrum of organ involvement, with an emphasis on kidney injury, and comment on pitfalls in establishing the diagnosis. The considerable variance in presentation-with admissions both to internal and neurological units-emphasises the high index of suspicion required to arrive at the right diagnosis, particularly in countries of perceived low risk such as Austria.

Community-acquired acute kidney injury in tropical countries

Community-acquired acute kidney injury (AKI) in developing tropical countries is markedly different from AKI in developed countries with a temperate climate, which exemplifies the influence that environment can have on the epidemiology of human diseases. The aetiology and presentation of AKI reflect the ethnicity, socioeconomic factors, climatic and ecological characteristics in tropical countries. Tropical zones are characterized by high year-round temperatures and the absence of frost, which supports the propagation of infections that can cause AKI, including malaria, leptospirosis, HIV and diarrhoeal diseases. Other major causes of AKI in tropical countries are envenomation; ingestion of toxic herbs or chemicals; poisoning; and obstetric complications. These factors are associated with low levels of income, poor access to treatment, and social or cultural practices (such as the use of traditional herbal medicines and treatments) that contribute to poor outcomes of patients with AKI. Most causes of AKI in developing tropical countries are preventable, but strategies to improve the outcomes and reduce the burden of tropical AKI require both improvements in basic public health, achieved through effective interventions, and increased access to effective medical care (especially for patients with established AKI).

Leptospirosis masquerading as infectious enteritis

Leptospirosis is a zoonosis caused by a ubiquitous spirochete of the genus Leptospira and is endemic to the tropics. Prompt diagnosis and treatment are important in reducing the morbidity and mortality that can be associated with this illness. We report the case of a 30-year-old Israeli traveler who had returned from Thailand and developed fever, chills, vomiting and diarrhea. An unexpectedly high value of creatinine expanded the diagnostic possibilities beyond travelers' diarrhea. Leptospirosis was confirmed serologically and the traveler eventually recovered. Leptospirosis should be considered in the differential diagnosis of travelers returning with fever and gastrointestinal complaints.

Early identification of leptospirosis as an ignored cause of multiple organ dysfunction syndrome

Leptospirosis is the most common zoonosis in the world but remains underreported, owing to protean manifestations and ignorance about the disease among health care providers in Taiwan. From September 2000 to March 2006, surveillance of 455 patients with multiple organ dysfunction syndrome with unclear cause or clinical suspicion of leptospirosis was performed. Diagnosis was further confirmed by microscopic agglutination test or isolation of Leptospira. Cases were classified as excluded based on confirmed etiology other than leptospirosis or negative paired serologic test. Forty-two patients were confirmed as having leptospirosis, which accounted for 9.2% of total patients with multiple organ dysfunction syndrome. Forty-nine excluded cases were identified for a case-control analysis for clinical distinction. The most common presentations of leptospirosis were fever (97.6%), acute kidney injury (85.7%), and jaundice (61.9%). The leptospirosis group showed lower urine specific gravity (cutoff value, 1.0145) and enlarged kidney size (cutoff value, 11.05 cm) as compared with the excluded cases by multivariate logistics regression. Delayed antibiotic administration prolongs the duration of hospitalization (R2 = 0.486, P < 0.01). No mortality has been found in the leptospirosis group after initiation in 2003 of rapid immunoglobulin M serology assay that showed considerably high sensitivity and specificity. Leptospirosis accounts for a salient cause of multiple organ dysfunctions in Taiwan. Early awareness of leptospirosis by distinct presentations, followed by prompt antibiotics therapy, can dramatically save the patients. The easily performed rapid immunoglobulin M serology assay is suitable as a rapid screening test for the diagnosis of leptospirosis.

Acute kidney injury in the tropics

Acute kidney injury (AKI) is one of the most challenging problems faced by clinicians in the tropics owing to its fast-changing burden. AKI in the tropics is strikingly different from that in the developed world in terms of etiology and presentation. In addition, there is a stark contrast between well-developed and poor areas in the tropics. The true epidemiological picture of AKI in the tropics is not well understood due to the late presentation of patients to tertiary centers. Infections remain the major culprit in most cases of AKI, with high mortality rates in the tropics. Human immunodeficiency virus-related AKI, related to nephrotoxicity due to antiretroviral therapy, is on the rise. Acute tubular necrosis and thrombotic microangiopathy are the most common mechanisms of AKI. A notable problem in the tropics is the scarcity of resources in health centers to support patients who require critical care due to AKI. This article reviews the unique and contrasting nature of AKI in the tropics and describes its management in each situation.

Infecção por leptospiras em ovinos e caracterização da resposta inflamatória renal

As Leptospiroses são zoonoses graves de distribuição mundial que afetam o homem e outros animais. A infecção em animais, geralmente, é inaparente, ou os sintomas quando presentes são similares a outras infecções. Neste estudo foram colhidos soros de 119 ovinos e seus respectivos rins durante abate em feiras livres no município de Teresina-Piauí. Pela técnica de soroaglutinação microscópica (SAM) obtiveram-se 34 amostras sorológicas positivas para um ou mais sorovares de Leptospira spp., com taxa de ocorrência de 28,6% de anticorpos anti-leptospiras, sendo 23 casos de infecção para um único sorovar e 11 com coaglutinações para dois ou mais sorovares. Dentre os sorovares patogênicos, o de maior ocorrência foi o Autumnalis (29,4%). A análise histopatológica de 36 fragmentos de rins revelou alterações túbulo intersticiais em 33 (91,7%) animais soro-reagentes. Lesões tubulares foram observadas em 20 (55,5%) animais soro-reagentes. A presença de leptospiras, pela técnica de Warthin Starry, foi observada em 8 (22,20%) amostras positivas. Pela técnica de imunoperixidase, de 20 casos analisados, foi verificada a presença de leptospira em 12 (60%) de 20 amostras positivas. Nos animais soro-reagentes, o infiltrado inflamatório foi significantemente mais evidente na região córtico-medular e cortical do que na região medular (p=0,000), mas não houve diferença entre animais soro-reagentes e soro não-reagentes. Cilindros hialinos nos túbulos proximais estavam presentes em quantidade significantemente maior nos animais soro-reagentes comparados aos não-reagentes (p=0,0001). Em glomérulos, foi observada lesão discreta. Os resultados deste estudo mostram que ovinos soro-reagentes para leptospiras apresentam lesões renais túbulo intersticiais, com presença de leptospiras nos túbulos, o que confere a esses animais a condição de disseminadores da infecção.

Two patients who developed leptospirosis-associated acute renal failure within the same season

In the autumn two patients with general malaise were consecutively admitted to the department of internal medicine of our hospital in the northern region of Nagasaki Prefecture. Since both patients were engaged in rice farm work and showed conjunctival suffusion and pain of the gastrocnemius muscle, leptospirosis was suspected. The first patient required temporary hemodialysis for renal dysfunction, whereas liver dysfunction developed in the second patient. The disease was remitted by antimicrobial agents. A diagnosis of leptospirosis was made serologically in both patients. Leptospirosis should be considered as a differential diagnosis when a patient engaged in farm work in the autumn has typical symptoms, and an early initiation of treatment after onset is important.

Leptospiral Acute Renal Failure: Effects of Dopamine and Furosemide

From unpublished experience of clinicians in the rural tropics, the combination of furosemide and dopamine is beneficial in the management of mild acute renal failure in tropical disease. We studied two groups of patients with leptospirosis and mild acute renal failure whose serum creatinine ranged from 2.4 to 5 mg/dL and fractional excretion of sodium varied from 1.21 to 2.08%. Group 1, consisting of 9 patients with the serum creatinine ranging from 2.4 to 5 mg/dL, served as the control. They received only penicillin G sodium and supportive treatment. Group 2, consisting of 8 patients with the serum creatinine ranging from 2.8 to 5 mg/dL, received, in addition to penicillin, dopamine (renal dose) and furosemide along with fluid and electrolyte replacement. The control group ran the usual clinical course of acute renal failure, and 3 patients required dialysis. There was profuse diuresis, and the recovery of renal function was faster in group 2 patients. Dopamine and furosemide are therefore useful in mild acute renal failure in leptospirosis. It is felt that this combination could be beneficial in the management of mild acute ischemic renal failure due to a clean single insult.

Leptospiral nephropathy

Leptospirosis is recognized as a globally re-emerging zoonosis. Interstitial nephritis is the principal feature of the disease. Leptospirosis-induced acute kidney injury typically is nonoliguric and includes hypokalemia. Tubular function alterations precede a decrease in the glomerular filtration rate, which could explain the high frequency of hypokalemia. Studies in human beings and animals have shown increased urinary fractional excretion of potassium and sodium, as well as an increased potassium/sodium ratio, suggesting increased distal potassium secretion caused by increased distal sodium delivery consequent to functional impairment of proximal sodium reabsorption. Confirming these findings, Western blot studies have shown lower renal expression of the sodium/hydrogen exchanger isoform 3 and of aquaporin 2, together with higher renal expression of the Na-K-2Cl cotransporter NKCC2, in infected animals. The severe form (Weil's disease) manifests as diffuse alveolar hemorrhage, pulmonary edema, acute respiratory distress syndrome, or a combination of these features, accompanied by acute kidney injury and can be highly lethal. Antibiotic treatment is efficient in the early and late/severe phases. For critically ill leptospirosis patients, the following are recommended: daily hemodialysis, low daily net fluid intake (because of the risk for pulmonary hemorrhage), and lung-protective strategies (low tidal volumes and high positive end-expiratory pressures after recruitment maneuvers).

Community-acquired acute kidney injury in Asia

Asia, the largest continent in the world, is heterogeneous in the ethnic, socioeconomic, and developmental status of its populations. A vast majority of it is poor with no adequate access to modern health care, making an accurate estimation of the nature and extent of acute kidney injury (AKI) difficult. Community-acquired AKI in otherwise healthy individuals is common, and the population developing AKI is younger compared with its counterparts in Europe or North America. The etiologic spectrum varies in different geographic regions of Asia depending on environmental, cultural, and socioeconomic factors. Some of the etiologic factors include AKI in relation to infectious diseases, intravascular hemolysis caused by glucose 6-phosphate dehydrogenase deficiency, poisonings caused by industrial chemicals or copper sulphate, animal venoms, natural medicines, heat stroke, and after complications of pregnancy. Preventive opportunities are missed because of failure to recognize the risk factors and early signs of AKI. Patients often present late for treatment, leading to multi-organ involvement and increased mortality. The exact etiologic diagnosis cannot be established in many instances because of a lack of appropriate laboratory support. Modern methods of renal replacement therapy are not universally available; and intermittent peritoneal dialysis is still widely practiced in many areas.

Altered fluid, electrolyte and mineral status in tropical disease, with an emphasis on malaria and leptospirosis

Fluid, electrolyte and mineral perturbations are prevalent features of tropical disease. Hemodynamic alterations, fever, nitrogen wasting, and changes in membrane transport and acid-base balance contribute to these perturbations. Models of malaria and leptospirosis have been used to show that common hemodynamic changes in tropical disease include decreased systemic vascular resistance, increased cardiac output and increased renal vascular resistance. Blood volume is initially increased, but it decreases as disease progresses. Response to fluid loading is decreased. Diabetes insipidus is occasionally observed in malaria. Hyponatremia occurs frequently in tropical diseases, as a result of increased levels of antidiuretic hormone (vasopressin), entry of sodium into cells, sodium loss and resetting of osmoreceptors. Natriuresis and kaliuresis are observed in patients with leptospirosis. Large amounts of sodium and potassium are lost in stool as a result of diarrhea. Hypernatremia is uncommon, whereas hypokalemia caused by hyperventilation is often observed (more frequently in patients with leptospirosis and kaliuresis). During severe tropical infective episodes, hyperkalemia results from intravascular hemolysis or rhabdomyolysis, and occasionally from decreased activity of Na+,K+-ATPase. Hypocalcemia, hypomagnesemia and hypophosphatemia are common features of both malaria and leptospirosis. Loss of magnesium in the urine is uniquely associated with leptospiral nephropathy. Hypozincemia and hypocupremia can also develop during tropical infection, and might interfere with a patient's immune response. These electrolyte and mineral perturbations are transient and quickly resolve when the disease is controlled.

Early diagnosis of leptospirosis by immunoglobulin M immunoblot testing

There is an urgent need for the development of serodiagnostic approaches with improved sensitivity for patients with acute leptospirosis. Immunoblots were performed on 188 sera collected from 74 patients with laboratory-confirmed early leptospiral infection to detect immunoglobulin M (IgM) antibodies to antigens pooled from 10 leptospiral strains prevalent in Thailand. Sera from patients with other febrile diseases served as controls. IgM reactivity to seven distinct antigens, with apparent molecular masses of 14 to 18, 19 to 23, 24 to 30, 32, 35/36, 37, and 41/42 kDa, was observed. The low-molecular-mass 14- to 18-kDa band was the most frequently detected antigen, being recognized in sera from 82.4% of patients during the first 3 days after the onset of symptoms. We evaluated the accuracy of the IgM immunoblot (IgM-IB) test by using reactivity to the 14- to 18-kDa band and/or at least two bands among the 19- to 23-, 24- to 30-, 32-, 35/36-, 37-, and 41/42-kDa antigens as the diagnostic criterion. The sensitivities of the IgM-IB test and the microscopic agglutination test (MAT) were 88.2% and 2.0%, respectively, with sera from patients 1 to 3 days after the onset of symptoms. In contrast, the IgM-IB test was positive with only 2/48 (4.2%) sera from patients with other febrile illnesses. The high sensitivity and specificity of the IgM-IB test for acute leptospirosis would provide greatly improved diagnostic accuracy for identification of patients who would benefit from early antibiotic intervention. In addition, the antigens identified by the IgM-IB test may serve as components of a rapid, accurate, point-of-care diagnostic test for early leptospirosis.

Weil's disease in a patient with chronic viral hepatitis and history of alcohol abuse

Clinical and laboratory diagnosis of severe leptospirosis (Weil's disease) may be difficult when other pathological processes that may cause similar clinical syndromes or affect immune response to infections coexist. In addition, the optimal management of the disease remains to be defined. We report on a case of Weil's disease, in which concurrent chronic hepatitis B virus infection and alcohol abuse caused diagnostic and therapeutic difficulties.

Immunogenicity of the recombinant leptospiral putative outer membrane proteins as vaccine candidates

Leptospiral putative outer membrane proteins (OMPs) are likely to be essential components of more effective vaccines. Recently completed genomic sequences of Leptospira allowed us to target putative OMPs for the development of recombinant vaccines. We focused on 12 putative OMPs that had no homology with other organisms listed in the NCBI database except MceI and MceII of Leptospira, which are approximately 25% homologous to MceI of Mycobacterium tuberculosis. All putative OMPs were cloned, expressed and purified as glutathione-S-transferase (GST) fusion proteins. Primary screening for immunoprotective potential was performed in hamsters challenged with an LD50 inoculum of low passage serovar Pomona. Out of these 12 OMPs three fusion proteins viz. rLp1454, rLp1118 and rMceII were found to be protective in a hamster model of leptospirosis. The protective efficacy was evaluated on the basis of survival, histopathological lesions in vital organs and antibody responses against each antigen. All the recombinant proteins were able to enhance the survival and reduce the histopathological lesions. In contrast, control animals immunized with rGST demonstrated low survival and had significant lesions. Further, these three proteins were evaluated for synergistic protective efficacy as compared to LigA, which has already been established as a protective antigen. Our results indicate that rLp1454, rLp1118, and rMceII showed protection individually and synergistically against serovar Pomona infection, which may help us to develop a multicomponent vaccine for leptospirosis.

Leptospirosis renal disease: understanding the initiation by Toll-like receptors

Leptospirosis is a prevalent infectious disease affecting both humans and animals worldwide. This infection is associated with occupational or recreational exposure to animals as well as contact with leptospires, particularly in flood-prone areas. Multiple organ dysfunctions may be associated with acute severe leptospirosis. A triad presentation of fever, jaundice, and acute renal failure in patients with acute multiple organ dysfunction should alert physicians to possible leptospirosis. Penicillin is effective and can rescue multiple organ failure if administered early. Renal involvement is common in leptospirosis characterized by tubulo-interstitial nephritis, and tubular dysfunction. Leptospira outer membrane proteins (OMPs) may elicit tubular injury and inflammation through Toll-like receptors (TLRs)-dependent pathway followed by activation of nuclear transcription factor kappa B and mitogen-activated protein kinases and a differential induction of chemokines and cytokines relevant to tubular inflammation. Leptospira OMP may also induce activation of the transforming growth factor-beta/Smad-associated fibrosis pathway leading to accumulation of extracellular matrix. Thus, leptospirosis renal disease is a model for understanding the pathogenesis and initiation of pathogen-induced tubulo-interstitial nephritis and fibrosis. In particular, TLRs may be important mediators.

Acute Renal Failure Due to Leptospirosis in a Renal Transplant Recipient: A Brief Review of the Literature

We present the case of a 43-year-old renal transplant patient who presented with fever, malaise, pruritus, headache, and severe jaundice of 3-week duration following work in a rice field. He was found to have acute renal failure and severe hyperbilirubinemia with a positive serum leptospira antibody titer, making the diagnosis of Weil's disease. The patient responded to reduction in immunosuppressive medications and intravenous penicillin therapy with no need for dialysis. This is the second case of leptospirosis in a kidney transplant patient reported in the English literature.

Acute renal failure: a common manifestation of leptospirosis

Leptospirosis is an infectious disease caused by pathogenic leptospires and may vary in degree from an asymptomatic infection to severe and fatal illness. Sixteen patients (all males; aged 40+/-17 years) with leptospirosis were admitted to Sişli Etfal Training and Research Hospital between July 1998 and August 2003 and were retrospectively reviewed. Age, gender, occupation, clinical presentation, laboratory features, seasonal distribution of the disease, diagnostical approach, and prognostic factors were evaluated. Eleven patients were cured with no complication; four patients died of hepatic and/or renal failure. Eight patients presented with acute renal failure; seven of them needed dialytic support. One patient developed chronic renal failure and had to undergo regular hemodialysis. All deceased patients (aged 61+/-7 years) were anuric at admission and their serum bilirubin changed between 39-44 mg/dL (mean 41.3+/-2.2 mg/dL). Cured patients ranged in age from 14-62 years (34+/-14 years) and their serum bilirubin levels ranged from 9-35 mg/dL (23.1+/-11.4 mg/dL). Crystalline penicillin G 12 million U/day was administered to all patients. Six patients also received hepatic coma treatment. This study emphasizes that leptospirosis presenting with renal failure is a severe disease, and mortality is frequently related to delays in diagnosis due to lack of clinical understanding. The association of acute renal failure and jaundice should lead the clinician to suspect leptospirosis. We concluded that old age, oliguria/anuria, high serum bilirubin levels (>36 mg/dL), and high serum potassium levels might be risk factors that increase mortality in leptospirosis.

Haemodynamics in leptospirosis: Effects of plasmapheresis and continuous venovenous haemofiltration

BACKGROUND

Haemodynamics in leptospirosis may differ from that of sepsis because of frequently obeserved myocarditis and severe cholestatic jaundice. A haemodynamic study was therefore made in 10 patients with severe leptospirosis.

METHODS AND RESULTS

All patients had pulmonary complications with a chest X-ray showing either pulmonary oedema or infiltration. Renal failure was present in nine patients. Three patterns of haemodynamics were revealed. The first pattern was observed in six patients who showed increased cardiac index, decreased systemic vascular resistance, normal pulmonary capillary wedge pressure, normal pulmonary vascular resistance and hypotension. The pattern resembled that of sepsis. The second pattern shown in two patients with haemoptysis consisted of a normal cardiac index, normal systemic vascular resistance, normal blood pressure, normal pulmonary capillary wedge pressure and increased pulmonary vascular resistance. The third pattern was observed in two patients with severe jaundice who had hypotension, a relatively low cardiac index, increased systemic vascular resistance and normal pulmonary capillary wedge pressure, and pulmonary vascular resistance. Plasmapheresis performed in two patients and continuous venovenous haemofiltration performed in two patients improved systemic haemodynamics and normalized blood pressure with a resolution of lung signs.

The management of leptospirosis

How to quickly identify patients who should be treated for leptospirosis is a challenge. The interest of polymerase chain reaction (PCR) assays is currently being evaluated and rapid tests which can be used outside of the specialised laboratory, have recently been developed. Leptospires are sensitive to many antibiotics and few clinical studies have been made to compare different treatment options. Doxycycline is standard therapy in early leptospirosis treatment and chemoprophylaxis. Intravenous penicillin has been considered the drug of choice in late and severe disease, although it is now challenged by ceftriaxone, which use is easier. Ciprofloxacin may be combined with standard therapy in uveitis. Adjunctive therapies proposed in the management of severe forms of leptospirosis and Jarisch-Herxheimer reactions, are reviewed.