Sirolimus-induced isometric tubular vacuolization: a new sirolimus histopathologic manifestation

Histological Changes in Renal, Hepatic and Cardiac Tissues of Wistar Rats after 6 Weeks Treatment with Bipyridine Gold (III) Complex with Dithiocarbamate Ligands

Bipyridine gold (III) dithiocarbamate compounds are Gold-III complexes with promising cytotoxic properties. In this study, the subacute toxicity of a Gold (III) complex with dithiocarbamate ligand was evaluated. In the acute toxicity component, an initial LD₅₀ (38.46 mg/kg) was calculated by the administration of 50, 100, 200, 400, and 800 mg/kg of the compound to five groups of rats, respectively (n = 4 each). The sixth group was the control. The sub-acute toxicity component comprised the control group A (n = 6) and the study groups B (n = 10) and C (n = 4), which were administered 1 mL distilled water, 1/10 LD₅₀ (3.8 mg/kg), and 1/5 LD₅₀ (7.6 mg/kg), respectively, daily for 6 weeks. The alive animals were then sacrificed. Autopsy; preservation of renal, hepatic and cardiac tissue in buffered formalin; histopathological processing; microscopic evaluation; and comparison with the controls were sequentially conducted. In the subacute toxicity study at dosages of 3.8 mg/kg and 7.6 mg/kg, the renal tubules remained unaffected with no necrosis or vacuolization. Mild to moderate renal interstitial, hepatic capsular, lobular and portal inflammation along with mild focal hepatic vacuolization were present. At 3.8 mg/kg, the cardiac muscle fibers were unremarkable in 80% (n = 8) of the specimens, with mild focal hyalinization in 20% (n = 2) of the specimens. The same was observed in 50% (n = 2) of the specimens at 7.6 mg/kg. Variable congestion was evident in all of the groups. In the subacute toxicity study, the absence of renal tubular necrosis or vacuolization, the presence of mild inflammatory hepatic and renal alterations, and predominantly unremarkable cardiac muscle fibers suggest that Bipyridine gold (III)-dithiocarbamate is safe in animal studies and is a potential candidate for clinical trials.

Acute kidney injury pathology and pathophysiology: a retrospective review

Acute kidney injury (AKI) is the clinical term used for decline or loss of renal function. It is associated with chronic kidney disease (CKD) and high morbidity and mortality. However, not all causes of AKI lead to severe consequences and some are reversible. The underlying pathology can be a guide for treatment and assessment of prognosis. The Kidney Disease: Improving Global Outcomes guidelines recommend that the cause of AKI should be identified if possible. Renal biopsy can distinguish specific AKI entities and assist in patient management. This review aims to show the pathology of AKI, including glomerular and tubular diseases.

The Basics of Renal Allograft Pathology

Renal allograft biopsy provides critical information in the management of renal transplant patients, and must be analyzed in close collaboration with the clinical team. The histologic correlates of acute T-cell mediated rejection are interstitial inflammation, tubulitis, and endothelialitis; polyomavirus nephropathy is a potential mimic. Evidence of antibody-mediated rejection includes C4d deposition; morphologic acute tissue injury; and donor specific antibodies. Acute tubular injury/necrosis is a reversible cause of impaired graft function, especially in the immediate post-transplant period. Drug toxicity, recurrent disease, chronic injury, and other entities affecting both native and transplant kidneys must also be evaluated.

Oxaliplatin-induced renal tubular vacuolization

OBJECTIVE

Chemotherapy with oxaliplatin is used for a wide range of malignancies. Unlike other platinum derivatives, oxaliplatin has less nephrotoxicity. However, in recent years, there have been multiple reports of different forms of renal toxicity related to this agent.

CASE SUMMARY

A 40-year-old woman with colon adenocarcinoma developed jaundice, hematuria, and oliguria after the 36th cycle of oxaliplatin chemotherapy. Laboratory data revealed severe anemia, thrombocytopenia, increased creatinine, indirect hyperbilirubinemia, and high lactate dehydrogenase. A negative direct antiglobulin test and presence of <1% schistocytes in the peripheral blood smear stood against the diagnosis of immune-mediated hemolytic anemia or hemolytic uremic syndrome/thrombotic thrombocytopenic purpura. Renal biopsy was consistent with interstitial nephritis with tubular vacuolization in favor of drug-induced renal injury. Based on the Naranjo Probability Scale, the likelihood of oxaliplatin-induced renal injury in this case was probable.

DISCUSSION

To our knowledge, this is the first case report of renal tubular vacuolization with symptoms mimicking thrombotic microangiopathy in a patient on long-term chemotherapy with oxaliplatin.

CONCLUSIONS

Oxaliplatin can induce various forms of nephrotoxicity such as renal tubular vacuolization, acute tubular necrosis, renal tubular acidosis, and acute kidney injury secondary to hematological toxicity. Monitoring for renal function abnormalities and hemolysis should be considered during oxaliplatin-based chemotherapy.