Acute Interstitial Nephritis Following Snake Envenomation: A Single-Center Experience

The kidney histopathological spectrum of patients with kidney injury following snakebite envenomation in India: scoping review of five decades

INTRODUCTION

Snakebite is a public health problem leading to about 58,000 deaths every year in India. Kidney injury subsequent to snakebite envenomation is common with a reported prevalence of up to 32%. The current study aims to elucidate the spectrum of kidney histopathology in acute kidney injury (AKI) cases associated with snake bites.

METHODS

We searched seven electronic database studies to identify studies describing the histopathological findings in the kidney with snakebite envenomation. Two reviewers independently conducted titles and abstract screening as well as full-text evaluation for the final inclusion decision. Data were extracted as per the standardized form. We conducted narrative synthesis. Studies done exclusively on autopsy findings, in vitro studies, and case reports were excluded.

RESULTS

We retrieved 1464 studies and finally included 28 studies which met the eligibility criteria in the analysis. Most studies were single-centre and the majority were cross-sectional. Overall we included a total of 534 renal biopsies. Russell's viper bite was the most common cause related to AKI. Acute tubular necrosis was the most common finding followed by acute interstitial nephritis, acute cortical necrosis (ACN), and thrombotic microangiopathy (TMA). Vasculitis changes in vessels were rarely reported. Lesions such as ACN and TMA were associated with poor outcomes.

CONCLUSION

This analysis supports the notion that renal biopsies are important to guide prognosis and increase our knowledge about post-snake bite AKI pathophysiology.

Snake bite associated with acute kidney injury

Acute kidney injury (AKI) is a well-known life-threatening systemic effect of snake envenomation which commonly happens secondary to snake bites from families of Viperidae and Elapidae. Enzymatic toxins in snake venom result in injuries to all kidney cell types including glomerular, tubulo-interstitial and kidney vasculature. Pathogenesis of kidney injury due to snake envenomation includes ischaemia secondary to decreased kidney blood flow caused by systemic bleeding and vascular leakage, proteolytic degradation of the glomerular basement membrane by snake venom metalloproteinases (SVMPs), deposition of microthrombi in the kidney microvasculature (thrombotic microangiopathy), direct cytotoxic action of venom, systemic myotoxicity (rhabdomyolysis) and accumulation of large amounts of myoglobin in kidney tubules. Clinical features of AKI include fatigue, loss of appetite, headache, nausea, vomiting, oliguria and anuria. Monitoring of blood pressure, fluid balance, serum creatinine, blood urea nitrogen and serum electrolytes is useful in managing AKI induced by snake envenomation. Early initiation of anti-snake venom and early diagnosis of AKI are always desirable. Biomarkers which will help in early prediction of AKI are being explored, and current studies suggest that urinary clusterin, urinary neutrophil gelatinase-associated lipocalin, and serum cystatin C may play an important clinical role in the future. Apart from fluid and electrolyte management, kidney support including early and prompt initiation of kidney replacement therapy when indicated forms the bedrock in managing snake bite-associated AKI. Long-term follow-up is important because of chances of progression towards CKD.

Clinical assessment and pathophysiology of Bothrops venom-related acute kidney injury: a scoping review

Bothrops are one of the most common medically important snakes found in Latin America. Its venom is predominantly hemotoxic and proteolytic, which means that local lesion (edema and redness) and hemorrhagic symptoms are recurrent in envenoming by this snake. Although hemorrhage is usually the major cause of death, snakebite-related acute kidney injury is another potentially fatal clinical complication that may lead to chronic kidney disease. The present review highlights the main studies on Bothrops venom-related acute kidney injury, including observational, cross-sectional, case-control and cohort human studies available up to December 2019. The following descriptors were used according to Medical Subject Headings (MeSH): on Medline/Pubmed and Google Scholar "acute kidney injury" or "kidney disease" and "Bothrops"; on Lilacs and SciELO "kidney disease" or "acute kidney injury" and "Bothrops". Newcastle-Ottawa quality assessment scale was used to appraise the quality of the cross-sectional and cohort studies included. The selection of more severe patients who looked for health care units and tertiary centers is a risk of bias. Due to the methodological heterogeneity of the studies, a critical analysis of the results was performed based on the hypothesis that the design of the included studies influences the incidence of acute kidney injury. Fifteen human studies (total participants 4624) were included according to stablished criteria. The coagulation abnormalities (hemorrhagic symptoms, abnormal fibrinogen and activated partial thromboplastin time) were associated with acute kidney injury in the most recent studies reported. The findings observed in this review provide up-to-date evidence about the acute kidney injury pathogenesis following Bothrops syndrome. Studies pointed out that coagulation abnormalities comprise the major pathway for acute kidney injury development. This review may improve patient management by primary healthcare providers, allowing earlier diagnosis and treatment of Bothrops venom-related acute kidney injury.

Clinicopathological spectrum of snake bite-induced acute kidney injury from India

AIM

To study the clinico-pathological spectrum of snake bite-induced acute kidney injury (AKI).

METHODS

A retrospective study of patients admitted at Indira Gandhi Medical College Hospital, Shimla with snake bite-induced AKI from July 2003 to June 2016. Medical records were evaluated for patient’s information on demographic, clinical characteristics, complications and outcome. Outcomes of duration of hospital stay, requirement for intensive care unit support, treatment with dialysis, survival and mortality were analyzed. The survival and non survival groups were compared to see the difference in the demographic factors, clinical characteristics, laboratory results, and complications. In patients subjected to kidney biopsy, the findings of histopathological examination of the kidney biopsies were also analyzed.

RESULTS

One hundred and twenty-one patients were diagnosed with snake bite-induced AKI. Mean age was 42.2 ± 15.1 years and majority (58%) were women. Clinical details were available in 88 patients. The mean duration of arrival at hospital was 3.4 ± 3.7 d with a range of 1 to 30 d. Eighty percent had oliguria and 55% had history of having passed red or brown colored urine. Coagulation defect was seen in 89% patients. The hematological and biochemical laboratory abnormalities were: Anemia (80.7%), leukocytosis (75%), thrombocytopenia (47.7%), hyperkalemia (25%), severe metabolic acidosis (39.8%), hepatic dysfunction (40.9%), hemolysis (85.2%) and rhabdomyolysis (68.2%). Main complications were: Gastrointestinal bleed (12.5%), seizure/encephalopathy (10.2%), hypertension, pneumonia/acute respiratory distress syndrome (ARDS) and disseminated intravascular coagulation (9.1% each), hypotension and multi organ failure (MOF) (4.5% each). Eighty-two percent patients required renal replacement therapy. One hundred and ten (90.9%) patient survived and 11 (9.1%) patients died. As compared to the survival group, the white blood cell count (P = 0.023) and bilirubin levels (P = 0.006) were significant higher and albumin levels were significantly lower (0.005) in patients who died. The proportion of patients with pneumonia/ARDS (P = 0.001), seizure/encephalopathy (P = 0.005), MOF (P = 0.05) and need for intensive care unit support (0.001) was significantly higher and duration of hospital stay was significantly shorter (P = 0.012) in patients who died. Kidney biopsy was done in total of 22 patients. Predominant lesion on kidney biopsy was acute tubular necrosis (ATN) in 20 (91%) cases. In 11 cases had severe ATN and in other nine (41%) cases kidney biopsy showed features of ATN associated with mild to moderate acute interstitial nephritis (AIN). One patient only had moderate AIN and one had patchy renal cortical necrosis (RCN).

CONCLUSION

AKI due to snake bite is severe and a high proportion requires renal replacement therapy. On renal histology ATN and AIN are common, RCN is rare.