Latrodectism in Italy: First report of successful treatment of L. tredecimguttatus envenomation using L. mactans antivenom from North America

INTRODUCTION

Latrodectism is a rare, but potentially severe, clinical syndrome caused by spider of the genus Latrodectus. L. tredecimguttatus is widespread in Italy and its bite cause the injection of α-latrotoxin that cause depletion of acetylcholine at motor nerve endings and release of catecholamines at adrenergic nerve endings. We describe the first clinical case of L. tredecimguttatus poisoning successfully treated with L. mactans antivenom from North America.

CASE REPORT

A healthy 60-year-old patient was admitted to the emergency department after unknown insect sting or arachnid/snake bite. In the early morning, the patient was working in the countryside when he felt a sting-like pain in the medial area of the right lower leg, associated with an intense burning sensation. An hour later he developed agitation, hoarseness, sweating, abdominal distress and intense pain in his right leg. In the emergency room vital signs showed a hypertensive crisis, tachycardia and peripheral oxygen desaturation. ECG was normal and ABE showed mixed acid-base disorder. Blood tests showed leukocytosis with neutrophilia, high levels of myoglobin, with normal coagulation and normal plasmatic cholinesterase. Neck, thorax and abdomen CT scan, with and without contrast medium, was negative. Four hours after admission hypertension worsened with board like rigid abdomen and onset of fasciculations, tremors, miosis and intense regional sweating. The definitive diagnosis of poisoning by L tredecimguttatus was based on the clinical picture. Within short time the antidote was provided by the Poison Centre and administered. A marked improvement of the symptomatology was noted after 30 minutes, and 1 hour later all symptoms were under control. The patient was discharged after 2 days.

CONCLUSIONS

The clinical presentation of a patient suffering from latrodectism places the clinician in front of a challenging differential diagnosis. Following the suspicion, the first-line doctor is invited to discuss the case with a toxicologist, in order to confirm or exclude the diagnosis and implement all therapeutic measures. In our clinical case, the absence of organic lesions, laboratory tests not suggestive for other causes, and the presence of typical clinical feature suggested the diagnosis of L tredecimguttatus poisoning. This hypothesis was then supported by the close temporal relation between antivenom administration and symptoms improvement. With this case, we report the first use of L mactans antivenom from North America to treat L.tredecimguttatus poisoning and we confirm its effectiveness in counteracting latrodectism caused by this spider.

Simvastatin increases AQP2 urinary excretion in hypercholesterolemic patients: A pleiotropic effect of interest for patients with impaired AQP2 trafficking

We previously reported that statins improve the symptoms of X-linked nephrogenic diabetes insipidus (X-NDI) in animal models. The aim of this study was to verify whether the pleiotropic effect of statins on AQP2 trafficking and kidney-concentrating ability, observed in rodents, was attainable in humans at therapeutic doses. We enrolled 24 naïve hypercholesterolemic patients and measured urine excretion of AQP2 (uAQP2) at baseline and during 12 weeks of treatment with simvastatin 20 mg/day. Simvastatin induced a rapid and significant increase of uAQP2, reduced the 24-hour diuresis, and increased urine osmolality. These effects were also maintained in patients chronically treated with statins for at least 1 year. This study strongly suggests that statins may effectively enhance the efficacy of current pharmacological treatment of patients with urine-concentrating defects caused by defective AQP2 plasma membrane trafficking, like X-NDI.

Concomitant, sequential, and hybrid therapy for H. pylori eradication: a pilot study

BACKGROUND AND OBJECTIVE

Since the efficacy of the standard triple therapies for Helicobacter pylori eradication has decreased, novel antibiotic regimens have been introduced, including concomitant, sequential, and hybrid therapies. We aimed to compare the cure rates achieved by these new therapy regimens.

METHODS

This was a multicenter, open-label, pilot study enrolling consecutive non-ulcer dyspepsia patients with H. pylori infection never previously treated for the infection. Patients were randomized to receive one of the following treatments: (a) concomitant therapy: omeprazole 20mg, amoxicillin 1g, clarithromycin 500 mg, and tinidazole 500 mg for 5 days; (b) sequential therapy: omeprazole 20mg and amoxicillin 1g for 5 days followed by omeprazole 20mg, clarithromycin 500 mg, and tinidazole 500 mg for 5 days; (c) hybrid therapy: omeprazole 20mg, and amoxicillin 1g for 7 days followed by omeprazole 20mg, amoxicillin 1g, clarithromycin 500 mg, and tinidazole 500 mg, for 7 days. All drugs were administered twice daily. Bacterial eradication was checked 6 weeks after treatment by using a (13)C-urea breath test. A 10-day, second-line therapy with omeprazole 20mg, levofloxacin 250 mg, and amoxicillin 1g, all given twice daily, was offered to the eradication failure patients.

RESULTS

Overall, 270 patients were enrolled, but 13 patients early interrupted treatment due to side effects. At intention-to-treat (ITT) and per-protocol analysis (PP), the eradication rates were 85.5% and 91.6% with the concomitant regimen, 91.1% and 92.1% with the sequential therapy, and 80% and 85.7% with the hybrid regimen. Differences were not statistically significant. H. pylori infection was cured in 10 (55.6%) patients with the second-line regimen.

CONCLUSION

In our study, both concomitant and sequential therapy, but not hybrid therapy, reached high eradication rates. The success rate of second-line levofloxacin-based triple therapy is decreasing.

Breath tests with novel 13C-substrates for clinical studies of liver mitochondrial function in health and disease

Mitochondrial dysfunction determines the onset and progression of chronic deleterious conditions including liver diseases. The in vivo assessment of mitochondrial function, by providing more insight into the pathogenesis of liver diseases, would be a helpful tool to study specific functions and to develop diagnostic, prognostic and therapeutic strategies. The application of breath tests in the clinical setting to evaluate mitochondrial fitness may elegantly and noninvasively overcome the difficulties due to previous complex techniques and may provide clinically relevant information, i.e the effects of drugs presenting mitochondrial liabilities. Substrates meeting this requirement include alpha-ketoisocaproic acid and methionine, both decarboxylated by mitochondria. Long and medium chain fatty acids that are metabolized through the Krebs cycle and benzoic acid, which undergoes glycine conjugation, may also reflect the mitochondrial performance. This review focuses on the utility of breath tests to assess mitochondrial function in humans, thus contributing to unravel potential mechanisms associated with the dysfunction of this organelle network in the pathophysiology of liver diseases.

Dynamic 4D MR angiography versus multislice CT angiography in the evaluation of vascular hepatic involvement in hereditary haemorrhagic telangiectasia

PURPOSE

Hereditary haemorrhagic telangiectasia (HHT), or Rendu-Osler-Weber disease, is a rare autosomal dominant disorder characterised by mucocutaneous or visceral vascular abnormalities that may be widely distributed throughout the cardiovascular system. The purpose of this study was to compare multislice computed tomography angiography (MSCTA) and 4D dynamic contrast-enhanced magnetic resonance angiography (D-MRA) for evaluating vascular hepatic involvement in patients with HHT.

MATERIALS AND METHODS

Fifty-two consecutive HHT patients underwent MSCTA and D-MRA examinations for systematic analysis of vascular visceral involvement. The images from the two techniques were reviewed independently by two expert radiologists to identify the following vascular abnormalities: telangiectases or large vascular masses; perfusion disorders [transient hepatic attenuation differences (THADs)]; hepatic arteriovenous malformations (HAVMs). Data, as well as diameters of the common hepatic artery and portal vein, were compared with Cohen's kappa statistic, Student's t test and receiver operating characteristic (ROC) curve analysis, as appropriate.

RESULTS

Both MSCTA and D-MRA detected one or more of the following hepatic vascular abnormalities in 36/52 cases (telangiectases in 29/52, THADs in 23/52 and HAVMs in 25/52[CE1]). A good concordance was found between the two techniques when determining the type of hepatic shunt (κ=0.9). No statistically significant differences were found when comparing mean common hepatic artery and portal vein diameters (p=0.09 and 0.22, respectively) and their accuracy in predicting HAVMs.

CONCLUSIONS

D-MRA has the same diagnostic accuracy as MSCTA and has the advantage of being less invasive due to the absence of ionising radiation.