Acute interstitial nephritis associated with intermittent rifampin use

Mechanisms of Immunotoxicity: Stressors and Evaluators

The immune system defends the body against certain tumor cells and against foreign agents such as fungi, parasites, bacteria, and viruses. One of its main roles is to distinguish endogenous components from non-self-components. An unproperly functioning immune system is prone to primary immune deficiencies caused by either primary immune deficiencies such as genetic defects or secondary immune deficiencies such as physical, chemical, and in some instances, psychological stressors. In the manuscript, we will provide a brief overview of the immune system and immunotoxicology. We will also describe the biochemical mechanisms of immunotoxicants and how to evaluate immunotoxicity.

Acute Tubulo-Interstitial Nephritis Requiring Dialysis Associated with Intermittent Rifampicin Use: Case Report

Rifampicin is one of the most effective antibiotics used for the treatment of tuberculosis and severe staphylococcal infections. Intermittent administration of high doses of rifampicin has been associated with frequent adverse reactions, including hepatotoxicity and nephrotoxicity, sometimes resulting in acute renal failure. We describe a case of rifampicin-associated acute renal failure, with biopsy findings of tubulointerstitial nephritis; inflammatory cells were characterized by immunohistochemistry which showed immunoreactivity for CD3 and CD5 (T lymphocytes) and for CD68 (macrophages). The patient presented with a very rapid systemic reaction to the offending drug and rapid deterioration of renal function, which required dialysis treatment. The response to rifampicin discontinuation was excellent: no further therapy was required, as renal function began to improve within several days and returned to normal values (serum creatinine 1.17 mg/dl) seven months after the onset of symptoms.

When prescribing rifampicin the physician should investigate previous use of the drug, because re-exposure is a critical factor in predicting the possibility of drug-induced acute renal failure.

Early Detection of Acute Drug-Induced Liver Injury in Mice by Noninvasive Near-Infrared Fluorescence Imaging

Hepatocellular and cholestatic forms of drug-induced liver injury (DILI) are major reasons for late-stage termination of small-molecule drug discovery research projects. Biochemical serum markers are limited in their ability to sensitively and specifically detect both of these common DILI forms in preclinical models, and tissue-specific approaches to assessing this are labor intensive, requiring extensive animal dosing, tissue preparation, and pathology assessment. In vivo fluorescent imaging offers noninvasive detection of biologic changes detected directly in the livers of living animals. Three different near-infrared fluorescent imaging probes, specific for cell death (Annexin-Vivo 750), matrix metalloproteases (MMPSense 750 FAST), and transferrin receptor (Transferrin-Vivo 750) were used to measure the effects of single bolus intraperitoneal doses of four different chemical agents known to induce liver injury. Hepatocellular injury–inducing agents, thioacetamide and acetaminophen, showed optimal injury detection with probe injection at 18–24 hours, the liver cholestasis-inducing drug rifampicin required early probe injection (2 hours), and chlorpromazine, which induces mixed hepatocellular/cholestatic injury, showed injury with both early and late injection. Different patterns of liver responses were seen among these different imaging probes, and no one probe detected injury by all four compounds. By using a cocktail of these three near-infrared fluorescent imaging probes, all labeled with 750-nm fluorophores, each of the four different DILI agents induced comparable tissue injury within the liver region, as assessed by epifluorescence imaging. A strategy of probe cocktail injection in separate cohorts at 2 hours and at 20–24 hours allowed the effective detection of drugs with either early- or late-onset injury.

The combined fixed-dose antituberculous drugs alter some reproductive functions with oxidative stress involvement in wistar rats

The reproductive toxicity of combined fixed-dose first-line antituberculosis (CFDAT) regimen was assessed in rats. Thirty-two (32) Wistar rats weighing 168.1 ± 8.0 g were divided into four groups of eight rats per group. Two groups of male and female rats were administered oral distilled water (1.6 ml) and CFDAT drugs containing rifampicin, isoniazid, pyrazinamide and ethambutol (RIPE, 92.5 mg/m2 per body surface area) respectively for forty-five days. Serum follicle stimulating hormone, luteinizing and testosterone were reduced significantly (p < 0.05) in the treated male rats. Similarly, sperm count levels were decreased by 27.3% when compared with control. RIPE elevated serum oestrogen (p < 0.05), progesterone (p < 0.05) as well as prolactin (p > 0.05) levels in the treated females. In addition, RIPE reduced (p < 0.05) total proteins levels and increased (p < 0.05, 53%) catalase levels in male but not female animals. Superoxide dismutase, glutathione-S-transferase, glutathione peroxidase, reduced glutathione levels as well as lipid peroxidation were unaltered in all rats respectively. Histopathological studies revealed congested peritesticular vessels and no changes in the ovary when compared with control. Overall, our results demonstrate reproductive toxicity potentials of RIPE in the rat, thus, suggesting that these reproductive parameters be monitored during antituberculous chemotherapy.

Modulatory activity of antioxidants against the toxicity of Rifampicin in vivo

The World Health Organization (WHO) has shown concern about the burden of tuberculosis in the developing countries. Even though rifampicin is an effective drug in the management of tuberculosis, it has been documented to have some toxic effects in humans. Therefore, this study intends to investigate the modulatory effect of vitamins C and E on the hepatotoxicity, sperm quality and brain toxicity of Rifampicin. Forty Wistar albino rats were used, 10 animals per group. Group 1 animals received 0.3 mL of distilled water, the Group 2 animals received the therapeutic dose of rifampicin, Group 3 animals received therapeutic doses of rifampicin plus vitamin E, while Group 4 received therapeutic doses of rifampicin and vitamin C. The administration was performed orally during three months; the animals were sacrificed by cervical dislocation at the end of that period. Blood samples were collected and liver function and lipid profile was analyzed using fully automated clinical chemistry device. The liver, brain and reproductive organs underwent histopathological examination. Sperm samples were collected from the epididymis to achieve count and motility and morphological analysis. Results showed rifampicin alone to raise (p < 0.05) liver function enzymes (Aspartate amino transferase [AST], Serum alanine amino transferase [ALT] and Total Bilirubin) when compared with controls. While the vitamin E treated group showed remarkable protection, the vitamin C treated group showed questionable protection against the rifampicin induced liver damage. Sperm count results showed an important (p < 0.05) increase in the sperm quality in vitamin E and C treated groups. However, the vitamin E plus Rifampicin treated group showed increased lipid peroxidation. The histopathological findings revealed structural damages by rifampicin in liver, brain and epididymis while some remarkable architectural integrity was observed in the antioxidant-treated groups. It can be concluded that vitamin E or C improved sperm quality and protected against the brain damage caused by rifampicin. Moreover, vitamin E demonstrated remarkable hepatoprotection against rifampicin induced damage while vitamin C shows a questionable hepatoprotection.

Tubulointerstitial nephritis associated with minimal self reexposure to rifampin

We report the case of a 27-year-old Asian man who self-medicated with two capsules of rifampin 1 year after completing a continuous course of chemotherapy for tuberculosis that included that drug. He developed flank pain and edema and presented with uremia requiring dialysis; despite this, he had a serum potassium of only 3.5 mEq/L. Renal biopsy showed interstitial infiltrate with inflammation of the tubules. Renal function began to improve after a 3-week course of prednisone. This case is remarkable for the severity of the renal failure despite such a minimal self-exposure.

Drug-induced acute interstitial nephritis

Acute interstitial nephritis (AIN) is a form of inflammatory renal disease affecting predominantly the tubules and the interstitium. Drugs, particularly beta-lactam antibiotics and non-steroidal anti-inflammatory drugs, are currently the most common causes. The pathogenesis of drug-induced AIN is complex but there is good clinical evidence for an immune-mediated reaction. Clinical findings may be variable depending on the drug involved and the individual response. Most patients recover from the acute renal failure; however, in older patients or in patients with pre-existing renal insufficiency the recovery of renal function may be incomplete.

Nabumetone-associated interstitial nephritis

An 84-year-old woman was admitted to the hospital for progressive edema and decreased urine output. She had been taking nabumetone for 6 months, but had discontinued the agent 2 weeks before admission due to progressive edema. On admission she had 2-3+ pitting edema. Her serum electrolytes were sodium 122 mEq/L, potassium 5.9 mEq/L, chloride 93 mEq/L, and carbon dioxide 19 mEq/L. A urinalysis was significant for protein 3061 mg/dl, ketones 15 mg/dl, blood 2+, leukocytes 26-50/high-power field, and a protein:creatinine ratio 24.9. The serum creatinine and blood urea nitrogen concentrations were 2.7 mg/dl and 70 mg/dl, respectively. Throughout hospitalization the patient underwent aggressive diuresis. She developed congestive heart failure, and hemodialysis was initiated. A renal biopsy specimen on hospital day 9 showed tubular damage with minimal glomerular changes consistent with a diagnosis of nonsteroidal agent-induced nephropathy. On day 13, a 24-hour urine collection had a protein excretion of 3151 mg. Although the patient recovered from her renal failure (creatinine clearance 43 ml/min), the nephrotic syndrome persisted (13 g protein/day). The patient developed infectious complications and died on hospital day 32.