One-pot thiol-amine bioconjugation to maleimides: simultaneous stabilisation and dual functionalisation

Maleimide chemistry is widely used in the site-selective modification of proteins. However, hydrolysis of the resultant thiosuccinimides is required to provide robust stability to the bioconjugates. Herein, we present an alternative approach that affords simultaneous stabilisation and dual functionalisation in a one pot fashion. By consecutive conjugation of a thiol and an amine to dibromomaleimides, we show that aminothiomaleimides can be generated extremely efficiently. Furthermore, the amine serves to deactivate the electrophilicity of the maleimide, precluding further reactivity and hence generating stable conjugates. We have applied this conjugation strategy to peptides and proteins to generate stabilised trifunctional conjugates. We propose that this stabilisation-dual modification strategy could have widespread use in the generation of diverse conjugates.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Optimised approach to albumin-drug conjugates using monobromomaleimide-C-2 linkers

Conjugation of therapeutics to human serum albumin (HSA) using bromomaleimides represents a promising platform for half-life extension. We show here that the Cys-34 crevice substantially reduces the rate of serum stabilising maleimide hydrolysis in these conjugates, necessitating reagent optimisation. This improved reagent design is applied to the construction of an HSA-paclitaxel conjugate, preventing drug loss during maleimide hydrolysis.

Management of refractory lupus nephritis: challenges and solutions

Refractory lupus nephritis, broadly defined as failure to attain clinical remission after appropriate induction immunosuppressive therapy, is associated with an increased risk of progression to end-stage kidney disease and mortality. This is a challenging issue in clinical practice, as modern induction therapy despite proven efficacy can still be associated with treatment failure. Moreover, newer therapies have failed in recent years to displace or even match existing protocols for effective induction of remission. Refractory disease is generally assessed on the basis of clinical parameters, which may be unreliable, and renal biopsy, which is often not performed in a standard or timely fashion. Persisting histological inflammation in 30%–50% of patients who have attained clinical remission highlights the disparity between clinical and immunological response to therapy. The lack of an international consensus regarding what constitutes refractory lupus nephritis compounds clinician indecision regarding optimal management for these patients. Moreover, non-adherence to prescribed therapy versus primary treatment failure can be challenging to discriminate, and the time point at which non-response becomes treatment failure is unclear. In this review, we assess the key published evidence for the treatment of refractory lupus nephritis and provide practical recommendations based around the use of adjunctive therapies. These agents include rituximab and calcineurin inhibitors, with evidence consisting largely of observational or uncontrolled studies, as well as some of the biologic therapies currently under investigation through prospective clinical trials. The poor prognosis of refractory lupus nephritis demands regular review of patient response and the flexibility to switch or augment therapy.

A new class of recombinant human albumin with multiple surface thiols exhibits stable conjugation and enhanced FcRn binding and blood circulation

Human serum albumin is an endogenous ligand transport protein whose long circulatory half-life is facilitated by engagement with the human cellular recycling neonatal Fc receptor (hFcRn). The single free thiol located at Cys-34 in domain I of albumin has been exploited for monoconjugation of drugs. In this work, we increased the drug-to-albumin ratio potential by engineering recombinant human albumin (rHSA) variants with varying hFcRn affinity to contain three free, conjugation-competent cysteines. Structural analysis was used to identify positions for cysteine introduction to maximize rHSA stability and formation of the conjugated product without affecting hFcRn binding. The thiol rHSA variants exhibited up to 95% monomeric stability over 24 months and retained hFcRn engagement compared with a WT unconjugated control demonstrated by Biolayer Interferometry. The additional cysteines were further introduced into a panel of rHSA variants engineered with different affinities for hFcRn. After conjugation with three Alexa Fluor 680 (AF680) fluorophores, hFcRn binding was similar to that of the original triple-thiol nonconjugated rHSA variants (0.88 and 0.25 μm for WT albumin with or without 3xAF680 respectively, and 0.04 and 0.02 μm for a high hFcRn-binding variant with or without 3xAF680, respectively). We also observed a 1.3-fold increase in the blood circulatory half-life of a high hFcRn-binding triple-thiol variant conjugated with AF680 (t _½ = 22.4 h) compared with its WT counterpart (t _½ = 17.3 h) in mice. Potential high drug-to-albumin ratios combined with high hFcRn engagement are attractive features of this new class of albumins that offer a paradigm shift for albumin-based drug delivery.

Critical care usage after major gastrointestinal and liver surgery: a prospective, multicentre observational study

BACKGROUND

Patient selection for critical care admission must balance patient safety with optimal resource allocation. This study aimed to determine the relationship between critical care admission, and postoperative mortality after abdominal surgery.

METHODS

This prespecified secondary analysis of a multicentre, prospective, observational study included consecutive patients enrolled in the DISCOVER study from UK and Republic of Ireland undergoing major gastrointestinal and liver surgery between October and December 2014. The primary outcome was 30-day mortality. Multivariate logistic regression was used to explore associations between critical care admission (planned and unplanned) and mortality, and inter-centre variation in critical care admission after emergency laparotomy.

RESULTS

Of 4529 patients included, 37.8% (n=1713) underwent planned critical care admissions from theatre. Some 3.1% (n=86/2816) admitted to ward-level care subsequently underwent unplanned critical care admission. Overall 30-day mortality was 2.9% (n=133/4519), and the risk-adjusted association between 30-day mortality and critical care admission was higher in unplanned [odds ratio (OR): 8.65, 95% confidence interval (CI): 3.51-19.97) than planned admissions (OR: 2.32, 95% CI: 1.43-3.85). Some 26.7% of patients (n=1210/4529) underwent emergency laparotomies. After adjustment, 49.3% (95% CI: 46.8-51.9%, P<0.001) were predicted to have planned critical care admissions, with 7% (n=10/145) of centres outside the 95% CI.

CONCLUSIONS

After risk adjustment, no 30-day survival benefit was identified for either planned or unplanned postoperative admissions to critical care within this cohort. This likely represents appropriate admission of the highest-risk patients. Planned admissions in selected, intermediate-risk patients may present a strategy to mitigate the risk of unplanned admission. Substantial inter-centre variation exists in planned critical care admissions after emergency laparotomies.

Giri-nya-la-nha (talk together) to explore acceptability of targeted smoking cessation resources with Australian Aboriginal women

OBJECTIVES

To engage with health providers and Aboriginal women to understand what educational resources they want and need to support quit smoking attempts during pregnancy in order to develop a comprehensive evidence-based intervention.

STUDY DESIGN

Resources were developed in partnership with Aboriginal people, communities and academics with the aim to be inclusive of diverse communities. We then recruited Aboriginal women of various ages for yarning circles (focus groups) held in three Australian states to explore the acceptability of the resources and seeking further guidance as to the needs of Aboriginal women to support smoking cessation during pregnancy.

METHODS

Yarning circles were recorded and transcribed, and data were analysed independently by two researchers. Responses were coded using predetermined themes and further general inductive analysis for emergent themes.

RESULTS

Twenty-four Aboriginal women reflected on the resources they included: one pregnant woman, 15 mothers and eight elders. Predetermined themes of attraction, comprehension, cultural acceptability, graphics and layout, persuasion and self-efficacy were explored. Women suggested the following: resources need to be visually attractive and interactive to enhance self-efficacy; additional scientific content on health consequences of smoking and combining with non-pharmacological approaches to quitting.

CONCLUSION

Indigenous peoples prefer culturally targeted messages. However, developing effective Aboriginal health promotion requires more than a 'culturally appropriate' adaptation of mainstream resources. Consideration needs to be given to the diversity of Aboriginal communities when developing effective, evidence-based interventions. Aboriginal women are calling for innovative and interactive resources that enhance self-efficacy; the use of videos to explain medical and informational brochure content is well received. Requests for non-pharmacological cessation options were reported in New South Wales and Queensland and should be further explored.

Chemoselective Installation of Amine Bonds on Proteins through Aza-Michael Ligation

Chemical modification of proteins is essential for a variety of important diagnostic and therapeutic applications. Many strategies developed to date lack chemo- and regioselectivity as well as result in non-native linkages that may suffer from instability in vivo and adversely affect the protein's structure and function. We describe here the reaction of N-nucleophiles with the amino acid dehydroalanine (Dha) in a protein context. When Dha is chemically installed in proteins, the addition of a wide-range N-nucleophiles enables the rapid formation of amine linkages (secondary and tertiary) in a chemoselective manner under mild, biocompatible conditions. These new linkages are stable at a wide range of pH values (pH 2.8 to 12.8), under reducing conditions (biological thiols such as glutathione) and in human plasma. This method is demonstrated for three proteins and is shown to be fully compatible with disulfide bridges, as evidenced by the selective modification of recombinant albumin that displays 17 structurally relevant disulfides. The practicability and utility of our approach is further demonstrated by the construction of a chemically modified C2A domain of Synaptotagmin-I protein that retains its ability to preferentially bind to apoptotic cells at a level comparable to the native protein. Importantly, the method was useful for building a homogeneous antibody-drug conjugate with a precise drug-to-antibody ratio of 2. The kinase inhibitor crizotinib was directly conjugated to Dha through its piperidine motif, and its antibody-mediated intracellular delivery results in 10-fold improvement of its cancer cell-killing efficacy. The simplicity and exquisite site-selectivity of the aza-Michael ligation described herein allows the construction of stable secondary and tertiary amine-linked protein conjugates without affecting the structure and function of biologically relevant proteins.

Single-dose rituximab in refractory lupus nephritis

BACKGROUND

Off-label use of rituximab in lupus nephritis is reported to be beneficial. While the optimal dose is unknown, the regimen of four intravenous doses of 375 mg/m(2) is commonly employed, despite expense and potential side-effects.

AIM

To investigate the response to single-dose rituximab, added to standard corticosteroids plus additional immunosuppressive agent, in refractory lupus nephritis.

METHODS

Consecutive consenting patients with refractory lupus nephritis despite steroids plus either cyclophosphamide, mycophenolate or azathioprine were enrolled in this ethics-approved, open-label, prospective study. After baseline assessment, patients received one intravenous infusion of 375 mg/m(2) rituximab. Clinical, biochemical and serological (DsDNA, complement) responses to this dose were analysed. Complete renal response (CR) was defined as normalisation of creatinine, albumin, proteinuria and urinary RBCs and partial response (PR) as ≥50% improvement in at least one parameter, without deterioration in others. B-cell depletion was defined as peripheral CD19 lymphocyte count ≤0.05 × 10(9) /L.

RESULTS

Fourteen patients were enrolled in the study. All were B-cell-depleted until 8 months post-dose. Eleven patients (79%) responded (2CR, 9PR) at a median time of 5 months, with a 6-month probability of renal response of 43%. Five patients (45%) relapsed at a median time of 17 months. DsDNA titres decreased in 69%. Side-effects were minimal.

CONCLUSIONS

Single-dose rituximab is effective in relapsed/refractory lupus nephritis. Longevity of B-cell depletion with single-dose rituximab is similar to that of four doses with potentially fewer side-effects.

ITER-like antenna capacitors voltage probes: Circuit/electromagnetic calculations and calibrations

The analyses illustrated in this manuscript have been performed in order to provide the required data for the amplitude-and-phase calibration of the D-dot voltage probes used in the ITER-like antenna at the Joint European Torus tokamak. Their equivalent electrical circuit has been extracted and analyzed, and it has been compared to the one of voltage probes installed in simple transmission lines. A radio-frequency calibration technique has been formulated and exact mathematical relations have been derived. This technique mixes in an elegant fashion data extracted from measurements and numerical calculations to retrieve the calibration factors. The latter have been compared to previous calibration data with excellent agreement proving the robustness of the proposed radio-frequency calibration technique. In particular, it has been stressed that it is crucial to take into account environmental parasitic effects. A low-frequency calibration technique has been in addition formulated and analyzed in depth. The equivalence between the radio-frequency and low-frequency techniques has been rigorously demonstrated. The radio-frequency calibration technique is preferable in the case of the ITER-like antenna due to uncertainties on the characteristics of the cables connected at the inputs of the voltage probes. A method to extract the effect of a mismatched data acquisition system has been derived for both calibration techniques. Finally it has been outlined that in the case of the ITER-like antenna voltage probes can be in addition used to monitor the currents at the inputs of the antenna.

Retinal disease in the C3 glomerulopathies and the risk of impaired vision

BACKGROUND

Dense deposit disease and atypical hemolytic uremic syndrome are often caused by Complement Factor H (CFH) mutations. This study describes the retinal abnormalities in dense deposit disease and, for the first time, atypical haemolytic uremic syndrome. It also reviews our understanding of drusen pathogenesis and their relevance for glomerular disease.

METHODS

Six individuals with dense deposit disease and one with atypical haemolytic uremic syndrome were studied from 2 to 40 years after presentation. Five had renal transplants. All four who had genetic testing had CFH mutations. Individuals underwent ophthalmological review and retinal photography, and in some cases, optical coherence tomography, and further tests of retinal function.

RESULTS

All subjects with dense deposit disease had impaired night vision and retinal drusen or whitish-yellow deposits. Retinal atrophy, pigmentation, and hemorrhage were common. In late disease, peripheral vision was restricted, central vision was distorted, and there were scotoma from sub-retinal choroidal neovascular membranes and atypical serous retinopathy. Drusen were present but less prominent in the young person with atypical uremic syndrome due to a heterozygous CFH mutation.

CONCLUSIONS

Drusen are common in forms of C3 glomerulopathy caused by compound heterozygous or heterozygous CFH mutations. They are useful diagnostically but also impair vision. Drusen have an identical composition to glomerular deposits. They are also identical to the drusen of age-related macular degeneration, and may respond to the same treatments. Individuals with a C3 glomerulopathy should be assessed ophthalmologically at diagnosis, and monitored regularly for vision-threatening complications.

Finding the fifth intercostal space for chest drain insertion: guidelines and ultrasound

OBJECTIVES

International guidelines exist for chest drain insertion and recommend identifying the fifth intercostal space or above, around the midaxillary line. In a recent study, applying these guidelines in cadavers risked insertion in the 6th intercostal space or below in 80% of cases. However, there are limitations of cadaveric studies and this investigation uses ultrasound to determine the intercostal space identified when applying these guidelines in healthy adult volunteers.

METHODS

On each side of the chest wall in 31 volunteers, the position for drain insertion was identified using the European Trauma Course method, Advanced Trauma Life Support (ATLS) method, British Thoracic Society's 'safe triangle' and the 'traditional' method of palpation. Ultrasound imaging was used to determine the relationship of the skin marks with the underlying intercostal spaces.

RESULTS

Five methods were assessed on 60 sides. In contrast to the cadaveric study, 94% of skin marks lay over a safe intercostal space. However, the range of intercostal spaces found spanned the second to the seventh space. In 44% of women, the inferior boundary of the 'safe triangle' and the ATLS guidelines located the sixth intercostal space or below.

CONCLUSIONS

Current guidelines often identify a safe site for chest drain insertion, although the same site is not reproducibly found. In addition, women appear to be at risk of subdiaphragmatic drain insertion when the nipple is used to identify the fifth intercostal space. Real-time ultrasonography can be used to confirm the intercostal space during this procedure, although a safe guideline is still needed for circumstances in which ultrasound is not possible.

A platform for efficient, thiol-stable conjugation to albumin's native single accessible cysteine

Herein we report the use of bromomaleimides for the construction of stable albumin conjugates via conjugation to its native, single accessible, cysteine followed by hydrolysis. Advantages over the classical maleimide approach are highlighted in terms of quantitative hydrolysis and absence of undesirable retro-Michael deconjugation.

Adoptive T cell immunotherapy for treatment of ganciclovir-resistant cytomegalovirus disease in a renal transplant recipient

Cytomegalovirus (CMV) is a significant cause of morbidity, mortality and graft loss in solid organ transplantation (SOT). Treatment options for ganciclovir-resistant CMV are limited. We describe a case of ganciclovir-resistant CMV disease in a renal transplant recipient manifested by thrombotic microangiopathy-associated glomerulopathy. Adoptive T cell immunotherapy using CMV-specific T cells from a donor bank was used as salvage therapy. This report is a proof-of-concept of the clinical and logistical feasibility of this therapy in SOT recipients.

A Phase 2 study of migalastat hydrochloride in females with Fabry disease: selection of population, safety and pharmacodynamic effects

BACKGROUND

Fabry disease (FD) is a genetic disorder resulting from deficiency of the lysosomal enzyme α-galactosidase A (α-Gal A) which leads to globotriaosylceramide (GL-3) accumulation in multiple tissues. We report on the safety and pharmacodynamics of migalastat hydrochloride, an investigational pharmacological chaperone given orally every other day (QOD) to females with FD.

METHODS

This was an open-label, uncontrolled, Phase 2 study of 12 weeks with extension to 48 weeks in nine females with FD. Doses of 50mg, 150 mg and 250 mg were given QOD. At multiple time points, α-Gal A activity and GL-3 levels were quantified in blood cells, kidney and skin. GL-3 levels were also evaluated through skin and renal histology. Each individual GLA mutation was retrospectively categorized as being amenable or not to migalastat HCl based on an in vitro α-Gal A transfection assay developed in human embryonic kidney (HEK)-293 cells.

RESULTS

Migalastat HCl was generally well tolerated. Patients with amenable mutations seem to demonstrate greater pharmacodynamic response to migalastat HCl compared to patients with non-amenable mutations. The greatest declines in urine GL-3 were observed in the three patients with amenable GLA mutations that were treated with 150 or 250 mg migalastat HCl QOD. Additionally, these three patients all demonstrated decreases in GL-3 inclusions in kidney peri-tubular capillaries.

CONCLUSIONS

Migalastat HCl is a candidate oral pharmacological chaperone that provides a potential novel genotype-specific treatment for FD. Treatment resulted in GL-3 substrate decrease in female patients with amenable GLA mutations. Phase 3 studies are ongoing.

Ethnicity and lupus nephritis: an Australian single centre study

BACKGROUND

The clinical impression of Australian physicians is that systemic lupus erythematosus (SLE) is more prevalent and more severe in Asian patients than in their Caucasian counterparts. The presence and severity of lupus nephritis is a major determinant of prognosis in SLE, and largely determines disease impact.

AIM

To analyse the relationships between ethnicity and the prevalence and severity of lupus nephritis (LN) in patients attending a tertiary referral centre (The Royal Melbourne Hospital (RMH)).

METHODS

The ethnicity of all known patients with biopsy-proven LN was determined according to three definitions of ethnicity - ancestry, country of origin and primary language spoken. The prevalence of Asian ethnicity in the LN cohort was analysed across severity class, and was compared with the prevalences of Asian ethnicity in the general population within the hospital's geographic area, and with that in the relevant RMH cohorts of inpatients and outpatients, over the same time period.

RESULTS

Within this single tertiary centre, Asian patients were disproportionately represented in both the systemic lupus erythematosus (SLE) and the LN patient groups, although the distribution of histological severity of LN was not significantly different from Caucasian patients.

CONCLUSION

This study supports the common clinical impression that SLE is more common and more severe in the Asian-Australian population. Asian patients with SLE were more commonly diagnosed with LN. However, the spectrum of histological severity of LN was similar in Asian and Caucasian patients.

Severe infusion reactions to fabry enzyme replacement therapy: rechallenge after tracheostomy

A 34-year-old male patient with Fabry disease (OMIM 301500) commenced enzyme replacement therapy (ERT) with Agalsidase alfa, with positive clinical response. Infusion reactions, initially mild and easily managed, commenced during his 13th infusion, and continued over the next 3 years. Severity of reactions subsequently increased despite very slow infusion, extended prophylactic medication and attempted desensitisation, requiring regular intensive care unit (ICU) admissions. Facial oedema and flushing, throat tightness, headache and joint pain typically occurred 4-36 h after completion of most infusions, responding rapidly to subcutaneous adrenaline. Low titre specific IgG seroconversion was noted at 12 months, with subsequent reversion to negative after 5 years, despite persistence of infusion reactions. Specific IgE and skin testing was negative. Trial of ERT product switch to Agalsidase-beta resulted in no improvement in reactions. At 5 years, ERT was ceased in the face of recurrent ICU readmissions. In the face of progressive clinical deterioration, he underwent tracheostomy to allow recommencement of ERT. Two years later, he has clinically improved on regular attenuated dose Agalsidase-beta, administered by slow infusion in a local hospital setting.

Thrombotic thrombocytopenic purpura is associated with a high relapse rate after plasma exchange: a single-centre experience

BACKGROUND

Thrombotic thrombocytopenic purpura (TTP) is a rare condition characterized by microangiopathic haemolytic anaemia, thrombocytopenia, renal and/or neurological dysfunction secondary to microvascular or macrovascular thrombosis. Despite advances in treatment, TTP remains a serious condition with significant morbidity and mortality.

METHODS

We undertook an audit of patients with TTP over 14 years to assess remission, relapse, survival and factors predictive of outcome using current therapy based on plasma exchange with fresh-frozen plasma.

RESULTS

Forty patients were identified between January 1992 and December 2005. Thirty-one (82%) achieved complete response (CR) to therapy using plasma exchange with fresh-frozen plasma (median 11 exchanges) and steroids. Twelve (37%) relapsed a median of 14 days following cessation of therapy, with multiple relapses occurring in two patients. TTP-related death occurred in four patients during their initial presentation and in two during subsequent relapse. Four patients were only partially responsive to first-line therapy. The absence of neurological features at presentation was the only factor predicting a sustained CR to first-line therapy (P = 0.027, log-rank analysis). The mean duration of inpatient treatment was 18 days (range 4-38 days) with 30% of patients requiring intensive care admission. Thirty-four per cent of patients acquired central venous line infection, with a median of two episodes of line sepsis per patient.

CONCLUSION

Our results indicate the need for better treatments to reduce the high early relapse rate and significant mortality associated with current therapy.

Neurology of Fabry disease

BACKGROUND

Fabry disease has diverse neurological manifestations, many of which influence morbidity and quality of life.

AIMS

The aim of the study was to document the clinical and subclinical neurological manifestations in a cohort of Australian patients with Fabry disease, using multiple clinical tools and a multidisciplinary approach.

METHODS

Participants completed focused questionnaires and underwent clinical neurological examination, Neurocognitive testing using Mini Mental State Examination and Neuropsychiatry Unit Cognitive Screen, Quantitative Sensory Testing (QST), autonomic assessment using RR interval variation, intracranial magnetic resonance imaging (MRI) and audiology. In subsets of patients who had previously undergone QST and/or prospective serial quality-of-life assessments over the previous 5 years, results before and after enzyme replacement therapy were compared.

RESULTS

Twenty hemizygotes and two heterozygotes were recruited. The age (mean +/- standard deviation (SD)) of male participants was 40.4 +/- 11.9 years (range 20-62 years); the women were aged between 20 and 56 years. Increasing age was strongly associated with increasing neurological disability. Clinical peripheral neuropathy predominantly affected thermal sensation in all patients, with variable involvement of pinprick and light touch. QST confirmed these findings. Clinical cerebellar tests were commonly abnormal: this has not been previously reported in the absence of symptomatic cerebrovascular disease. There was hearing loss was in 90% of patients and no patient older than 44 years had normal hearing. MRI lesion prevalence increased with age. Despite neurological complications being common, formal cognitive testing was basically normal. QST thresholds for pain showed a significant change after enzyme replacement therapy.

CONCLUSIONS

Neurological complications in Fabry disease are common, complex and may be devastating. All patients studied had neurological involvement, with protean and diverse manifestations.

Anti-CD20 antibody in thrombotic thrombocytopenic purpura refractory to plasma exchange

Thrombotic thrombocytopenic purpura is a rare condition characterized by microangiopathic haemolytic anaemia, thrombocytopenia, altered neurology, renal impairment and fever. While plasma exchange has reduced mortality from more than 90% to between 10 and 30%, a proportion of cases fail to respond. Rituximab may be efficacious in the management of refractory cases of thrombotic thrombocytopenic purpura. We present two cases in which rituximab was used with successful outcomes. Treatment resulted in resolution of severe clinical and haematological abnormalities in both patients. There has been no relapse after 16 months follow up. Our experience supports the use of rituximab in difficult cases of TTP. Ongoing evaluation of its use is in progress at our institution.

Fabry disease: baseline medical characteristics of a cohort of 1765 males and females in the Fabry Registry

The Fabry Registry is a global observational research platform established to define outcome data on the natural and treated course of this rare disorder. Participating physicians submit structured longitudinal data to a centralized, confidential database. This report describes the baseline demographic and clinical characteristics of the first 1765 patients (54% males (16% aged < 20 years) and 46% females (13% < 20 years)) enrolled in the Fabry Registry. The median ages at symptom onset and diagnosis were 9 and 23 years (males) and 13 and 32 years (females), respectively, indicating diagnostic delays in both sexes. Frequent presenting symptoms in males included neurological pain (62%), skin signs (31%), gastroenterological symptoms (19%), renal signs (unspecified) (17%), and ophthalmological signs (11%). First symptoms in females included neurological pain (41%), gastroenterological symptoms (13%), ophthalmological (12%), and skin signs (12%). For those patients reporting renal progression, the median age at occurrence was 38 years for both sexes, but onset of cerebrovascular and cardiovascular events was later in females (median 43 and 47 years, respectively) than in males (38 and 41 years, respectively). This paper demonstrates that in spite of the considerable burden of disease in both sexes that begins to manifest in childhood or adolescence, the recognition of the underlying diagnosis is delayed by 14 years in males and 19 years in females. The Fabry Registry provides data that can increase awareness of common symptoms in all age groups, as well as insight into treated and untreated disease course, leading to improved recognition and earlier treatment, and possibly to improved outcomes for affected individuals.

Intermittent claudication – atypical presentation, diagnosis and treatment

A unique case of a man with Fabry's disease and associated small vessel vasculopathy manifesting as recurrent episodes of intermittent claudication is described. The case highlights the concept that microvascular involvement due to local accumulation of glycosphingolipid in the smooth muscle fibres of vessel walls may be responsible for claudicant symptoms in such patients rather than the more classical macrovascular insufficiency.

Sirolimus: a single center experience in combination with calcineurin inhibitors

A retrospective survey was performed to establish patient and graft outcome for all 41 patients at our centre receiving sirolimus (SRL) in combination with calcineurin inhibition (CNI) as primary therapy for the 6 years prior to March 2002. Patient mortality [12%; n = 5 (TTP, lymphoma, mucormycosis, and small bowel perforation] was significantly higher at 3 months compared with those not receiving SRL, but not thereafter. 12.8% had delayed graft function and 33% had one or more episodes of rejection in the first 6 months. Mean GFR at 12 months was significantly lower (47.3 mL/min) in the SRL group compared with those not receiving SRL (51.3 mL/min). Twenty-two patients had a 12-month protocol biopsy; CNI toxicity was present in 36%. SRL was associated with significant hyperlipidaemia (serum cholesterol, 5.2 +/- 1.4 at baseline vs 7.3 +/- 1.7 mmol/L at 3 months, P <.001; triglycerides, 2.3 +/- 1.4 at baseline vs 2.7 +/- 1.1 mmol/L at 3 months, P <.05). Mild thrombocytopenia occurred in 23% but was not associated with haemorrhagic events. LDH increased by 62%, remaining elevated out to 2 years post engraftment. Seven patients developed insulin requiring diabetes mellitus, similar to the rate observed in our general transplant population.Thus, in this early experience, SRL in combination with CNI was associated with significant mortality and morbidity including CNI toxicity, presumably a reflection of a heavy burden of immunosuppression. However, 1-year graft survival on SRL was similar to the mean Australia-wide graft survival regardless of immunosuppression. The future use of SRL may center around CNI sparing and avoidance type protocols.

Clinical features of Fabry's disease in Australian patients

BACKGROUND

Anticipating the prospect of specific treatment, we studied a large group of Australians with Fabry's disease.

AIMS

We aimed to: (i) document the clinical features of Fabry's disease in Australian patients, (ii) test the hypothesis that clinical features vary with specific mutation and blood group and (iii) assess small-fibre peripheral nerve function.

METHODS

A questionnaire was forwarded to all Australian patients known to us. Patients were invited to attend for clinical, renal cardiac, ophthalmological and neurological assessment.

RESULTS

Sixty-seven patients (29 men and 38 women) from 18 families participated. Diagnosis in index cases was delayed by > or = 10 years in nearly all families. Common clinical features are: (i) episodic acroparaesthesia (100% of hemizygotes; 53% of heterozygotes), (ii) anhydrosis (93%; 1%), (iii) characteristic rash (93%; 13%), (iv) renal disease (69%; 21%), (v) ischaemic heart disease (28%; 26%), (vi) palpitations (62%; 29%), (vii) mitral valve murmurs (37%; 23%) and (viii) premature cerebrovascular disease (31%; 5%). Ophthalmic findings of cornea verticillata (96%; 76%) and anterior cataract (48%; 14%) were common. Findings were variable within and between families. In women, anhydrosis reliably predicts the presence of significant Fabry's renal disease. Small nerve fibre testing using quantitative sensory testing was clearly abnormal in 95% of male patients, and in those female patients with paraesthesiae.

CONCLUSIONS

Symptoms of anhydrosis, acroparaesthesiae, rash and renal disease suggest diagnosis of Fabry's. Women are commonly symptomatic, and the advent of therapy highlights the practical advantage of earlier diagnosis.

Describing randomisation: patients' and the public's preferences compared with clinicians' practice

Explaining the concept of randomisation in simple terms to patients during the discussion of randomised clinical trials can be a difficult task for many health care professionals. We report the results of a questionnaire-based survey, using seven descriptions of randomisation taken from Corbett's study. We examined the preferences of the general public and patients towards the descriptions and compared the results with the clinicians' choice. Participants in the survey were 341 lay people without cancer, 200 patients with cancer and 200 oncologists from cancer centres throughout the UK. It was difficult to identify 'the best' way to describe the process of randomisation. The two most favoured statements for patients and members of the public included a very explicit statement that mentioned 'a computer', 'chance' and 'not the doctor's or patient's decision' and a succinct statement that played down the role of 'chance'. Clinicians chose neither of these statements as closely resembling their own practice. Patients and members of the public most disliked the statement 'a computer will perform the equivalent of tossing a coin to allocate you to one of two methods of treatment'. This analogy used by 26% of oncologists, was viewed as trivialising and upsetting in the context of determining treatment for life threatening disease.

Impact of acute rejection therapy on infections and malignancies in renal transplant recipients

BACKGROUND

Infections and malignancies are important causes of mortality and morbidity in renal allograft recipients. Their risk increases with increasing immunosuppression.

METHODS

In an attempt to quantitate the increase in the risk of these complications in association with antirejection therapy, we reviewed the records of all renal allograft recipients of our center transplanted during the cyclosporin era. We sub-divided the patients into three groups based on acute rejection episodes during the first 6 months posttransplant, and the treatment for acute rejection: those who did not develop AR--group 1 (n=168); those who had one or more episodes of acute rejection and were treated with high dose corticosteroids --group 2 (n=169); those who in addition to corticosteroids required cytolytics (OKT3) and/or other drugs--group 3 (n=141).

RESULTS

52% patients in group 1, 71% patients in group 2 and 86% patients in group 3 had one or more episodes of infection during the first 6 months posttransplantation. Relative risk for group 2 and 3 were 1.56 (P=0.0002) and 2.98 (P<0.00001), respectively. Infection/patient rates at 6 months were 0.67, 1.23, and 2.79 in groups 1, 2, and 3 respectively. Groups 1 and 2 had a similar number of cases with squamous and basal cell carcinoma, however, there were few cases with these malignancies in group 3. No case of lymphoma was seen in group 1; there were four cases in group 2 and nine in group 3. There was no significant difference in patient survival in group 1 and 2, however, patients in group 3 had a reduced patient survival (1 vs. 3 P<0.001, 2 vs. 3 P=0.067). Graft survival was best in group 1 and worst in group 3 (1 vs. 2 P<0.05; 1 vs. 3 P<0.00001; 2 vs. 3 P<0.01).

CONCLUSIONS

In renal transplant recipients the risk of infections and lymphoma increases with increasing immunosuppression and hence mortality and morbidity associated with it. When adding a potent immunosuppressive agent to rescue a kidney one needs to consider the serious and at times fatal side effects given the modest beneficial effect on long-term outcome.

Effects of perindopril on renal histomorphometry in diabetic subjects with microalbuminuria: a 3-year placebo-controlled biopsy study

We conducted a 3-year randomized placebo-controlled double-blind study to determine the effects of the angiotensin-converting enzyme (ACE) inhibitor perindopril (PE) on the progress of renal function and histology in subjects with diabetes and microalbuminuria. Forty non-insulin-dependent (NIDDM) and insulin-dependent (IDDM) diabetic subjects, either normotensive or hypertensive, were randomly assigned to receive PE (n = 20) or placebo (n = 20). A percutaneous renal biopsy was performed initially in all patients and repeated in 29 patients after 3 years. The mean glomerular volume, glomerular basement membrane (GBM) thickness, interstitial fibrosis, sclerosed glomeruli, and volume fraction of capillary lumina were measured histomorphometrically. Before treatment, both groups had similar clinical characteristics, blood pressure, glycosylated hemoglobin (Hb), albumin excretion rate, glomerular filtration rate (GFR), serum creatinine, and renal structural damage. Blood pressure was well controlled in both groups. After 3 years' therapy, there was no significant change in renal function and albuminuria in the PE or placebo groups. The increase in GBM thickness in nine paired biopsies was significantly less in PE-treated subjects (P = .0275). Interstitial fibrosis tended to increase less in the PE group, although this did not reach statistical significance. This study indicates that long-term therapy with PE may decrease or delay the progression of structural glomerular damage in microalbuminuric diabetic subjects.