Shiga-Toxin E. coli Hemolytic Uremic Syndrome: Review of Management and Long-term Outcome

Purpose of Review

We review the pathophysiology of Shiga-Toxin Enteropathogenic–Hemolytic Uremic Syndrome (STEC-HUS), strategies to ameliorate or prevent evolution of STEC-HUS, management and the improved recognition of long-term adverse outcomes.

Recent Findings

Following on from the preclinical evidence of a role for the complement system in STEC-HUS, the use of complement blocking agents has been the major focus of most recent clinical research. Novel therapies to prevent or lessen HUS have yet to enter the clinical arena. The long-term outcomes of STEC-HUS, similarly to other causes of AKI, are not as benign as previously thought.

Summary

Optimizing supportive care in STEC-HUS is the only current recommended treatment. The administration of early isotonic fluids may reduce the severity and duration of STEC-HUS. The role of complement blockade in the management of STEC-HUS remains unclear. The long-term sequelae from STEC-HUS are significant and patients with apparent full renal recovery remain at risk.

Use of belatacept to maintain adequate early immunosuppression in calcineurin-mediated microangiopathic hemolysis post-renal transplant

We report a 17-yr-old boy who developed a microangiopathic hemolytic anemia presumed secondary to tacrolimus shortly following a living-related donor renal transplant. This was initially managed by plasmapheresis. Reinstitution of calcineurin inhibition using cyclosporine led to recurrence of hemolysis, so an alternative agent was needed. He was commenced on monthly intravenous belatacept, with no further recurrence of the hemolysis, and subsequent stable graft function. Modulation via CTLA-4 offers an alternative immunosuppressive tactic if current regimens produce graft threatening adverse effects. The method of administration and frequency of dosage of belatacept also lends itself well to the high-risk period of adolescence and transition. We propose that belatacept may therefore also have utility in difficult cases complicated by poor concordance, common in the adolescent age group.

Enhanced carbon pump inferred from relaxation of nutrient limitation in the glacial ocean

The modern Eastern Equatorial Pacific (EEP) Ocean is a large oceanic source of carbon to the atmosphere. Primary productivity over large areas of the EEP is limited by silicic acid and iron availability, and because of this constraint the organic carbon export to the deep ocean is unable to compensate for the outgassing of carbon dioxide that occurs through upwelling of deep waters. It has been suggested that the delivery of dust-borne iron to the glacial ocean could have increased primary productivity and enhanced deep-sea carbon export in this region, lowering atmospheric carbon dioxide concentrations during glacial periods. Such a role for the EEP is supported by higher organic carbon burial rates documented in underlying glacial sediments, but lower opal accumulation rates cast doubts on the importance of the EEP as an oceanic region for significant glacial carbon dioxide drawdown. Here we present a new silicon isotope record that suggests the paradoxical decline in opal accumulation rate in the glacial EEP results from a decrease in the silicon to carbon uptake ratio of diatoms under conditions of increased iron availability from enhanced dust input. Consequently, our study supports the idea of an invigorated biological pump in this region during the last glacial period that could have contributed to glacial carbon dioxide drawdown. Additionally, using evidence from silicon and nitrogen isotope changes, we infer that, in contrast to the modern situation, the biological productivity in this region is not constrained by the availability of iron, silicon and nitrogen during the glacial period. We hypothesize that an invigorated biological carbon dioxide pump constrained perhaps only by phosphorus limitation was a more common occurrence in low-latitude areas of the glacial ocean.

Reversible chronic pulmonary fibrosis associated with MMF in a pediatric patient: a case report

We describe a case of chronic mineralizing pulmonary elastosis in a seven-yr-old boy following DD renal transplantation for Wilms tumour. Fourteen months post-transplantation he developed respiratory symptoms with lung biopsy demonstrating chronic mineralizing pulmonary elastosis thought to be secondary to immunosuppression with MMF. Symptomatic resolution occurred following MMF cessation.

A comparison of self-reported satisfaction between adolescents treated in a "teenage" unit with those treated in adult or paediatric units

BACKGROUND

Despite recommendations that adolescents should have in-patient management amongst their peers, there is little literature to support this. The study aim was to evaluate and contrast patient satisfaction for teenage cancer patients treated in two settings. The first is a split site unit (a paediatric ward and adult cancer centre in different locations within one city) and the second, a dedicated adolescent unit for patients aged 13-20.

PROCEDURE

Eligible patients aged 13-20 years received treatment from September 1997 to June 2000 and totalled sixty-five adolescents. The patients were identified at both centres from departmental databases. Postal questionnaires (the Youth Satisfaction Questionnaire) were sent to those eligible.

RESULTS

Patients receiving treatment in the teenage cancer unit (TCU) were not significantly more satisfied overall than those receiving treatment in adult or paediatric units. However, significant differences were noted in: recreational and relaxation facilities (P < 0.005, P < 0.0002), studying space (P < 0.004), ward noise (P < 0.02), and company of the same age (P < 0.0001). The Grade Point Average (a score of all specific items) was higher in favour of the TCU (P < 0.03). Patients at both centres were dissatisfied with hospital food and menus offered.

CONCLUSIONS

Adolescents with cancer are satisfied with the overall care they receive independent of whether it is a TCU or a split site unit. Teenagers are significantly more satisfied with environmental aspects of care in the TCU. More research is required to establish the correct provision for teenagers with cancer. This is the first study that contrasts satisfaction between different centres and thus adding to an understanding of the needs of teenagers with cancer.

Secular variation of iron isotopes in north atlantic deep water

A high-precision iron isotope time series for a ferromanganese crust demonstrates that the iron isotope composition in North Atlantic Deep Water has changed substantially over the past 6 million years and that iron isotope variations in the crust are closely correlated to those of lead isotopes. The close correlation between the two isotope series indicates that the observed iron isotope variations predominantly reflect those of iron input from terrigenous sources and provides no evidence for biologically induced mass fractionation within North Atlantic Deep Water.