EULAR/PReS endorsed consensus criteria for the classification of childhood vasculitides

BACKGROUND

There has been a lack of appropriate classification criteria for vasculitis in children.

OBJECTIVE

To develop a widely accepted general classification for the vasculitides observed in children and specific and realistic classification criteria for common childhood vasculitides (Henoch-Schönlein purpura (HSP), Kawasaki disease (KD), childhood polyarteritis nodosa (PAN), Wegener's granulomatosis (WG), and Takayasu arteritis (TA)).

METHODS

The project was divided into two phases: (1) the Delphi technique was used to gather opinions from a wide spectrum of paediatric rheumatologists and nephrologists; (2) a consensus conference using nominal group technique was held. Ten international experts, all paediatricians, met for the consensus conference. Agreement of at least 80% of the participants was defined as consensus.

RESULTS

Consensus was reached to base the general working classification for childhood vasculitides on vessel size. The small vessel disease was further subcategorised into "granulomatous" and "non-granulomatous." Final criteria were developed to classify a child as HSP, KD, childhood PAN, WG, or TA, with changes introduced based on paediatric experience. Mandatory criteria were suggested for all diseases except WG.

CONCLUSIONS

It is hoped that the suggested criteria will be widely accepted around the world because of the reliable techniques used and the international and multispecialist composition of the expert group involved.

Epilepsy, ataxia, sensorineural deafness, tubulopathy, and KCNJ10 mutations

BACKGROUND

Five children from two consanguineous families presented with epilepsy beginning in infancy and severe ataxia, moderate sensorineural deafness, and a renal salt-losing tubulopathy with normotensive hypokalemic metabolic alkalosis. We investigated the genetic basis of this autosomal recessive disease, which we call the EAST syndrome (the presence of epilepsy, ataxia, sensorineural deafness, and tubulopathy).

METHODS

Whole-genome linkage analysis was performed in the four affected children in one of the families. Newly identified mutations in a potassium-channel gene were evaluated with the use of a heterologous expression system. Protein expression and function were further investigated in genetically modified mice.

RESULTS

Linkage analysis identified a single significant locus on chromosome 1q23.2 with a lod score of 4.98. This region contained the KCNJ10 gene, which encodes a potassium channel expressed in the brain, inner ear, and kidney. Sequencing of this candidate gene revealed homozygous missense mutations in affected persons in both families. These mutations, when expressed heterologously in xenopus oocytes, caused significant and specific decreases in potassium currents. Mice with Kcnj10 deletions became dehydrated, with definitive evidence of renal salt wasting.

CONCLUSIONS

Mutations in KCNJ10 cause a specific disorder, consisting of epilepsy, ataxia, sensorineural deafness, and tubulopathy. Our findings indicate that KCNJ10 plays a major role in renal salt handling and, hence, possibly also in blood-pressure maintenance and its regulation.

The postnatal management of hydronephrosis diagnosed by prenatal ultrasound

A total of 112 patients (142 kidneys) presented with hydronephrosis consistent with ureteropelvic junction obstruction that had been diagnosed by prenatal ultrasound. The kidneys were classified as having poor, moderate or good function based on isotope imaging at 3 months after birth. Of 9 kidneys that showed poor function 3 recovered sufficient function on pigtail drainage to justify preservation and these patients underwent pyeloplasty. Of 27 kidneys with moderate function 23 also underwent pyeloplasty and 14 of these demonstrated improvement in function postoperatively. Of the 100 kidneys in the good function group that were followed conservatively 23 underwent pyeloplasty during followup primarily because of an observed decrease in function. We propose that there is no indication for immediate pyeloplasty in infants with prenatally diagnosed hydronephrosis who demonstrate good function postnatally.

Long-term outcome of boys with posterior urethral valves

One hundred and fourteen boys with posterior urethral valves were treated between 1966 and 1975. Four died during the first hospital admission, 6 died from renal failure during childhood, 1 died from other causes and 15 were lost to follow-up. Eighty-eight were reviewed 11 to 22 years after diagnosis and the renal outcome of 98 patients is therefore known. Approximately one-third of patients presented under 1 month of age, between 1 month and 1 year, and over 1 year respectively. Bilateral vesicoureteric reflux was observed in one-quarter of the boys, more frequently in those presenting in the first month of life. Half of the patients were treated by primary valve ablation and half underwent temporary upper tract diversion: the outcome was worse for the diverted group. One-third of the boys had a long-term bad outcome for renal function. This outcome was associated with early presentation, bilateral vesicoureteric reflux and day-time urinary incontinence after the age of 5 years. The association of bad outcome with incontinence points to continuing bladder dysfunction as a major determinant of long-term outcome for renal function.

Endothelial dysfunction late after Kawasaki disease

BACKGROUND

Kawasaki disease (KD) is a systemic vasculitis of childhood with widespread vascular endothelial damage in the acute stage. Long-term complications, such as myocardial infarction and death, are recognized, but the extent and nature of late vascular abnormalities that might predispose to these events have not been studied.

METHODS AND RESULTS

We used high-resolution ultrasound to study endothelial function in the brachial artery of 20 patients 5 to 17 years after acute KD (median, 11 years) and compared findings with those in 20 age- and sex-matched control subjects. Vascular responses to reactive hyperemia (with flow increase leading to endothelium-dependent dilation) and to sublingual glyceryl trinitrate (GTN; endothelium-independent dilation) were recorded. The relationship between endothelium-dependent vascular responses and features of the endothelium acute illness was examined. There was no difference in baseline vessel diameter, degree of reactive hyperemia, or response to GTN between patients and control subjects. In contrast, flow-mediated dilation was markedly reduced in KD patients compared with control subjects (3.1% versus 9.4%; P < .001). Late endothelium-dependent responses were not related to features of the acute illness.

CONCLUSIONS

Abnormalities of systemic endothelial function are present many years after resolution of acute KD, even in patients without detectable early coronary artery involvement. Because this may be an important factor in the genesis of late vascular complications, long-term follow-up of all patients with KD is indicated.

Endothelial and platelet microparticles in vasculitis of the young

OBJECTIVE

Microparticles are released from endothelial cells in response to a variety of injurious stimuli and recently have been shown to be increased in a number of diseases associated with endothelial dysfunction. This study examined endothelial microparticle (EMP) and platelet microparticle (PMP) profiles in children with systemic vasculitis to test the hypothesis that EMPs may provide a noninvasive means of examining endothelial activation or injury.

METHODS

The study cohort comprised 39 children with systemic vasculitis at various stages of disease activity, 24 control children with febrile disease, and a control group of 43 healthy subjects. Plasma was ultracentrifuged at 17,000g for 60 minutes, and the microparticle pellets were examined using flow cytometry.

RESULTS

Plasma from patients with active systemic vasculitis contained significantly higher numbers of E-selectin-positive EMPs compared with that from patients in remission, healthy controls, or febrile disease controls (P = 0.000 for each). A similar result was obtained for the numbers of EMPs expressing the marker CD105. There was also a significant increase in PMPs expressing CD42a in the active vasculitis group as compared with the other groups, but this difference was not significant for PMPs expressing P-selectin. The EMP counts correlated with the Birmingham Vasculitis Activity Score and the acute-phase reactant levels in the patients with systemic vasculitis, but there was a poor correlation overall between EMP counts and the acute-phase reactant levels in the febrile disease controls.

CONCLUSION

EMPs may provide a window to the activated endothelium and could provide important pathophysiologic insights into the vascular injury associated with vasculitis of the young.

Autosomal recessive polycystic kidney disease

The clinical features of 55 cases of autosomal recessive polycystic kidney disease (ARPCKD) have been reviewed. Each had evidence of ARPCKD. The outcomes of 87% were known; 24 had died. Twenty-four of 31 were seen between 1980 and 1986; 7 could not be traced. Forty-five percent presented under 1 month; 38% between 1 month and 1 year; and 9 cases over 1 year. Hyponatraemia occurred in 15 out of 19 aged less than 3 months; hypertension occurred in 65%; splenomegaly in 47% of those surviving more than 3 months. Portocaval shunts were done in 5 aged 2-12 years. Thirteen died of renal failure, 6 under 1 year, and 7 between 1 year and 13 years. Life-table survival rates calculated from birth revealed that 86% were alive at 3 months, 79% at 1 year, 51% at 10 years, and 46% at 15 years. Calculations based on patients who survived to 1 year of age showed that 82% were alive at 10 years and 79% at 15 years. These results reveal an improved prognosis for a condition once assumed to be fatal.

Clinical features in 17 paediatric patients with Wegener granulomatosis

The aim of this report was to describe childhood patients with Wegener granulomatosis (WG) from one centre, to analyse the variety of clinical manifestations seen and compare the data with other published paediatric and adult series. The records of 17 patients with WG who were under the care of Great Ormond Street Hospital for Children (GOSH) from 1981 to 1998 were reviewed. We analysed presenting features before admittance to GOSH and the clinical signs observed whilst the children were under the care of the hospital. Of 17 patients, 13 were females and there was a male/female ratio of 1:3.25. Among the patients there were 2 sisters. The age of the patients at disease onset varied from 2 weeks to 14 years. The median/mean age was 6/6.3 years. American College of Rheumatology criteria for diagnosing WG were fulfilled in 11 of 17 patients. The frequency of different system involvement was: respiratory 87%, kidneys 53%, sinuses 35%, joints 53%, eyes 53%, nervous system 12%, skin 53%. cANCA was positive in 10 patients (59%), but pANCA was negative in all measured sera. Kidneys were involved in 2 of 8 patients (25%) with the disease onset from 0 to 5 years and in 7 of 9 patients (78%) with the disease onset from 6 to 14 years ( P<0.05). cANCA was positive in 7 of 9 patients with kidney disease (78%) and in 2 of 8 patients (25%) without kidney involvement ( P<0.05). Colchicine as a supplement to prednisolone and cytotoxic/immunosuppressant drugs was used effectively in 5 patients.

Angioplasty for renovascular hypertension in children: 20-year experience

OBJECTIVE

Our aim was to evaluate the clinical outcomes, safety, and efficacy of percutaneous transluminal angioplasty for renovascular hypertension in children.

METHODS

A retrospective review of data for all children with renovascular hypertension who underwent percutaneous transluminal angioplasty at a single center between 1984 and 2003 was performed. Patients with renal transplants and inflammatory multisystem diseases were excluded.

RESULTS

Thirty-three children, 1.9 to 17.9 years of age (median: 10.3 years), underwent renal angioplasty and/or stenting. Underlying syndromes were present in 10. On angiograms, 16 had bilateral renal artery stenosis, 15 intrarenal disease, 8 aortic stenosis, and 7 cerebrovascular disease. Forty-eight percutaneous transluminal angioplasty procedures were performed, including 15 stenting procedures. There was a high rate of restenosis after stenting (7 of 19 cases, compared with 2 of 27 cases after balloon dilation). Outcomes were cured (ie, blood pressure normal without treatment) for 9 patients, improved blood pressure with same or reduced treatment for 7, blood pressure maintained in >95th percentile because of cerebrovascular disease for 2, no change in blood pressure despite technical success for 10, and technical failure for 5. Blood pressure control improved in 11 of 13 children who had main renal artery disease alone and in 6 of 20 with associated intrarenal disease or stenoses in other vascular beds. There was 1 procedure-related death and 5 minor complications.

CONCLUSIONS

Angioplasty produced clinically worthwhile improvement for approximately 50% of patients. High incidence rates of extrarenal involvement and intrarenal disease and a high restenosis rate after stenting accounted for poor blood pressure control in the rest.

Plasma renin activity and aldosterone concentration in children

Using semi-micro methods, plasma renin activity (PRA) and plasma aldosterone concentration (PA) were measured concurrently in 79 healthy children aged 1 month to 15 years to establish a reference range. PRA and PA varied inversely with age. Eleven children with renal hypertension had higher PRA and PA than age-matched controls. In contrast, PRA was much greater in 38 saline-depleted children. PA was not uniformly increased in this group and was within the normal range in children with adrenal diseases compared with the high values seen in other salt-wasting states. The findings emphasise the need to relate data from patients to age-matched control values before attempting interpretation and suggest that sodium depletion is a more potent stimulator of renin-aldosterone release than renovascular disease or renal scarring in children. Plasma renin-aldosterone profiles were also valuable in discriminating between renal and adrenal causes of salt loss in childhood.

Autosomal recessive polycystic kidney disease: long-term outcome of neonatal survivors

Autosomal recessive polycystic kidney disease causes renal and hepatic dysfunction in childhood. We describe the clinical outcome of 52 children with this diagnosis born between 1950 and 1993. Currently 23 are alive, 24 dead and 5 have been lost to follow-up; 1 has been dialysed and 7 transplanted. Life-table analysis of the patients surviving the 1st month of life revealed an actuarial renal survival of 86% at 1 year and 67% at 15 years. The probability of requiring anti-hypertensive treatment was 39% at 1 year and 60% at 15 years of age. Bleeding from gastro-oesophageal varices occurred in 8 patients at a mean age of 12.5 years, and was preceded by haematological evidence of hypersplenism in 6 of them. The study indicates a relatively good prognosis for patients with this condition who survive the neonatal period and emphasises the importance of early detection and appropriate management of systemic and portal hypertension.

Nitric oxide synthase inhibitors and hypertension in children and adolescents

OBJECTIVE

To establish the role played by the circulating nitric oxide synthase inhibitors N(G)-monomethyl-L-arginine (L-NMMA), asymmetrical dimethyl arginine (ADMA) and symmetric dimethyl arginine (SDMA) and its association with hypertension of children and adolescents.

DESIGN

We measured plasma concentrations of L-NMMA, ADMA and SDMA in 38 hypertensives (median age 7.7 years) and in nine healthy normotensive controls (median age 8.2 years) using high-performance liquid chromatography. In addition, their plasma renin activity was determined. The subjects' glomerular filtration rates were calculated from plasma creatinine and height measurements. To determine the vasoactive potency of the arginine analogues, concentration-response curves were plotted for the responses in isolated endothelium-intact and endothelium-denuded mouse aortic rings that had been pre-contracted by administration of a threshold concentration of phenylephrine.

RESULTS

Plasma ADMA and SDMA concentrations in members of the hypertensive group [0.23 +/- 0.03 and 1.37 +/- 0.06 micromol/l, respectively (means +/- SEM)] were significantly higher than those in members of the control group (ADMA 0.10 +/- 0.01 micromol/l and SDMA 1.18 +/- 0.06 micromol/l). Plasma concentrations of L-NMMA were similar in members of the hypertensive (0.21 +/- 0.01 micromol/l) and control (0.18 +/- 0.02 micromol/l) groups. The glomerular filtration rate of the hypertensive group was below normal [70.4 +/- 5.4 ml/min per 1.73 m2 (mean +/- SEM)] and was significantly associated with elevated plasma concentrations of ADMA (r = -0.77, P < 0.001), SDMA (r = -0.38, P = 0.02) and L-NMMA (r = 0.35, P = 0.03). Higher plasma ADMA concentrations were associated with a lower plasma renin activity (r = -0.36, P = 0.04). The vasoactive potencies of ADMA (concentration for half-maximal effect with the endothelium intact 25.4 +/- 7.1 micromol/l) and L-NMMA (concentration for half-maximal effect with the endothelium intact 8.2 +/- 2.9 micromol/l) was significantly (P < 0.05) greater than that of SDMA. Both ADMA and L-NMMA (at 3 micromol/l concentrations) initiated a significant vasocontractile response from baseline (P = 0.03 and P < 0.001, respectively). These effects were absent after the endothelium had been removed. SDMA had no effect.

CONCLUSIONS

Plasma ADMA and SDMA levels are increased in hypertensive children. By inference from in-vitro data, ADMA appears to attain sufficient concentrations to produce a significant change in vascular tone and hence might play a role in the pathophysiology of childhood hypertension.

Kawasaki disease: an evidence based approach to diagnosis, treatment, and proposals for future research

This article proposes a clinical guideline for the diagnosis and treatment of Kawasaki disease in the UK based on the best available evidence to date, and highlights areas of practice where evidence is anecdotal or based on retrospective data. Future research as proposed by the London Kawasaki Disease Research Group is outlined, and clinicians are invited to prospectively enroll their suspected cases into this collaborative research project.

Clinicopathologic review of twelve children with nephropathy, Wilms tumor, and genital abnormalities (Drash syndrome)

The clinicopathologic and radiologic features of 12 children with complete and incomplete forms of Drash syndrome are reported. Their common denominator was a nephropathy. Four had the full triad, consisting of nephropathy, Wilms tumor, and genital abnormalities; five had nephropathy and genital abnormalities, and three had nephropathy and Wilms tumor. Of the 11 children who had proteinuria, eight had the nephrotic syndrome. Of the 10 whose condition progressed to end-stage renal failure, seven were less than 3 years of age. The histologic features of Wilms tumor were favorable in all seven children, and the tumor was bilateral in three. Of the nine patients who had genital abnormalities, eight had 46,XY karyotype and either ambiguous genitalia (six patients) or normal female phenotype (two). One other patient had a normal 46,XX female karyotype and phenotype but had both müllerian and wolffian structures and a streak ovary. Nine patients had a distinct pelvicaliceal abnormality not previously reported as a feature of this syndrome. Other congenital abnormalities were aniridia, mental retardation, deafness, nystagmus, and cleft palate. This syndrome must be considered in any infant with unexplained nephropathy, particularly in young phenotypic female infants and in those children with ambiguous genitalia or Wilms tumor with an early presentation.

Hemolytic uremic syndrome associated with invasive pneumococcal disease: the United kingdom experience

OBJECTIVE

To describe the presentation, management, and outcome of 43 cases of pneumococcal-associated hemolytic uremic syndrome (P-HUS). An increased incidence of P-HUS has been noted in the United Kingdom between January 1998 and May 2005.

STUDY DESIGN

Cases with microangiopathic hemolytic anemia (Hb <10 g/dL with fragmented RBCs), thrombocytopenia (platelet count < 130 x 10(9)/L), acute renal impairment with oliguria and elevated plasma creatinine for age, confirmed or suspected pneumococcal infection and/or T-activation were included.

RESULTS

The median age at presentation was 13 months (range, 5-39 months). Pneumococcus was identified in 34 of 43 cases; T-activation was identified in 36 of 37 cases. Twelve strains were serotyped: serotypes 3 (n = 2), 6A (n = 2), 12F (n = 1), 14 (n = 1), 19A (n = 6). Empyema was present in 23 of 35 pneumonia cases; 13 cases had confirmed (9) or suspected (4) pneumococcal meningitis; 36 cases required dialysis (median, 10 days; range, 2-240 days). The mortality rate was 11%, comprising 3 cases of meningitis, 1 case of sepsis and 1 case of pulmonary embolism at 8 months follow up while on dialysis. Follow-up data were available for 35 of 38 patients who survived (median follow-up period, 9 months; range, 1-63 months); of these, 10 patients had renal dysfunction, 1 patient was dialysis-dependent, 5 patients had hypertension and 8 patients had at least 1+ proteinuria on urinalysis.

CONCLUSION

P-HUS has increased compared with historic surveys (0/288 in 1985-1988; 8/413 in 1997-2001, 43/315 in 1998-May 2005). Early mortality remains high (8-fold that of VTEC-induced HUS). Ten of 12 strains identified would not be covered by the PCV7 vaccine.

The polymorphonuclear leucocyte count in childhood haemolytic uraemic syndrome

Review of data from 79 children with the haemolytic uraemic syndrome (HUS) showed that the polymorphonuclear leucocyte (PMN) count at presentation in childhood HUS predicts outcome. Logistic regression analysis of several features at presentation identified only the PMN count and the presence of a diarrhoeal prodrome as having a significant effect on the outcome (P less than 0.01 and P less than 0.001 respectively). The geometric mean PMN count was significantly raised in 70 children who had typical HUS following a diarrhoeal prodrome (D+ cases) compared with that of 9 children who had atypical disease without diarrhoea (D- cases) (t-test on log-transformed data, P less than 0.005). Fifty-seven children with D+ HUS who recovered completely had a significantly lower geometric mean PMN count than D+ cases with a bad outcome (P less than 0.001). Four of these patients, who died in the acute stage of the disease, had a significantly higher mean count than the rest of the D+ patients (P less than 0.001). Multiple regression analysis demonstrated that the PMN count in D+ cases was not significantly influenced by haemoglobin concentration, platelet count, length of the prodrome, or the administration of antibiotics in the prodromal period. A high PMN count at presentation in D+ HUS indicates a poor prognosis. The data emphasise the heterogeneity of HUS and suggest that PMN participate in the pathogenesis of the disorder in typical D+ cases but not in atypical D- cases.

Renovascular disease in childhood

Fifty-four children referred for investigation of hypertension had renovascular disease. In eight patients it was associated with neurofibromatosis, in three with idiopathic hypercalcemia of infancy, and in five cases it followed an arteritic illness. Fibromuscular dysplasia was the underlying abnormality in the majority of cases (46%). Twenty-six patients (48%) were first seen with accelerated hypertension; 38 children (70%) had bilateral renal arterial disease, and in 41 (76%), disease of the small intrarenal vessels was found. Renal vein renin ratios indicated unilateral disease in 31 cases; the results correlated with arteriography findings in 32 (62%) of 51 patients. Eleven children also had the middle aortic syndrome, and 9 of 16 patients, investigated by cerebral arteriography because of cranial bruits or focal neurologic signs, had cerebral vascular abnormalities. Twenty patients were treated surgically--10 by reconstructive procedures, 11 by nephrectomy or heminephrectomy, and 6 by transluminal angioplasty. Of these, 9 (45%) are normotensive with no treatment, 10 have a decreased requirement for antihypertensive drugs, and 1 had no improvement. Thirty-four patients were treated medically because of the extent of their disease; two patients have died of hypertensive complications. We conclude that renal vascular disease in children is often widespread, may be associated with intracerebral vascular disease, frequently affects both kidneys, including both intrarenal and extrarenal vessels, and is therefore not always amenable to surgical intervention and cure.

Biologic therapy in primary systemic vasculitis of the young

OBJECTIVES

To describe the biologic treatment regimens and report the efficacy and safety of biologic therapies in a multicentre series of children with primary systemic vasculitis (PSV).

METHODS

This was a retrospective descriptive case series of children with PSV treated with biologic therapy between February 2002 and November 2007. Primary retrospective outcome assessment measures were: daily corticosteroid dose; Birmingham Vasculitis Activity Score (BVAS); and adverse events (including infection rate).

RESULTS

Twenty-five patients median age 8.8 (range 2.4-16) years; 11 male with active PSV (n = 6 with anti-neutrophil cytoplasmic antibody associated vasculitides, n = 11 with polyarteritis nodosa, n = 7 with unclassified vasculitis and n = 1 with Behçet's disease) were treated with biologic agents including infliximab (n = 7), rituximab (n = 6), etanercept (n = 4), adalimumab (n = 1) or multiple biologics sequentially (n = 7). Overall, there was a significant reduction in BVAS from a median of 8.5 (range 5-32) at start of therapy to 4 (range 0-19) at median 32 months follow-up (P = 0.003) accompanied by significant reduction in median daily prednisolone requirement from 1 (range 0.2-2) to 0.25 (range 0-1) mg/kg/day, P = 0.000. For those receiving multiple biologic agents sequentially, a similar clinical improvement was observed with corticosteroid sparing. Infections occurred in 24%, the most severe in those receiving infliximab.

CONCLUSION

Our data provide retrospective evidence of efficacy of these agents, and highlight the associated infectious complications. Further multicentre standardization of treatment protocols and data collection to inform clinical trials of biologic therapy in systemic vasculitis of the young is required.

Interleukin-8 and polymorphoneutrophil leucocyte activation in hemolytic uremic syndrome of childhood

Polymorphoneutrophil leucocytes (PMNLs) are implicated in the pathogenesis of diarrhea-associated hemolytic uremic syndrome (D+ HUS). We investigated mechanisms of PMNL involvement by measuring tumor necrosis factor alpha (TNF alpha) and the novel cytokine, interleukin-8 (IL-8), a potent activator of neutrophils, together with alpha 1- antitrypsin-complexed elastase (alpha 1-AT-E) as a marker of neutrophil degranulation, and anti-neutrophil cytoplasmic antibodies (ANCA). IL-8 was not detected in the 17 normal children, but was significantly elevated in 20 of 25 D+ HUS children (P less than 0.005), and in three of nine children with non-diarrhea-associated (D-) HUS. Sequential data showed that IL-8 peaked transiently in the circulation, reaching a maximum just before a more protracted burst of alpha 1-AT-E. The IL-8 levels correlated significantly with circulating alpha 1-AT-E concentrations (r = 0.50, P less than 0.05). In D+ HUS IL-8 levels also correlated with the PMNL count (r = 0.63, P less than 0.005), and the highest values were seen in those children who died in the acute phase of the disease. TNF alpha was raised in only 1 of 16 D+ HUS children and in no patients were ANCA detected. The data suggest that PMNLs in HUS are recruited by IL-8, that this cytokine plays a key role in the PMNL activation which occurs, and that agents which suppress this recruitment and activation might play a therapeutic role in this disorder.

Management of hypertensive emergencies

Between 1975 and 1985, 454 patients with hypertension were admitted to the Renal Unit of the Hospital for Sick Children. A total of 110 (24%) patients presented with severely raised blood pressures deemed to require emergency management. At presentation 84/110 had symptoms and signs of long standing hypertension with neurological involvement. Between 1975 and 1980 bolus intravenous injections of diazoxide and/or hydralazine were used with the aim of reducing the blood pressure to within the normal range for age in the first 12-24 hours after admission. Of 57 patients treated in this way 13 developed hypotensive complications and four, whose blood pressures returned to normal within 24 hours of admission, suffered irreversible neurological damage. Subsequently, the management changed to the use of intravenous infusions of labetalol (1-3 mg/kg/hour) and/or sodium nitroprusside (0.5-8 micrograms/kg/min) to enable a more gradual controlled reduction of blood pressure over the first 96 hours of admission. Between 1980 and 1985, 53 patients were treated using this regimen. In all cases blood pressure reduction was achieved in a more controlled manner without further neurological impairment or serious irreversible side effects. From our experience, the use of labetalol and sodium nitroprusside by incremental infusion in the critical early phase of management has resulted in improved control of accelerated hypertension without the sudden hypotensive episodes seen when bolus injections are used.

Haemolytic-uraemic syndrome: an analysis of prognostic features

Seventy-two children with the haemolytic-uraemic syndrome were seen between 1969 and 1980 at The Hospital for Sick Children and Guy's Hospital, London. They probably constitute the majority of such cases in south-east England during that period. Boys and girls were affected equally, the mean age at presentation was 3.5 years, and a peak incidence of the disorder in summer months was observed. In 52 (72%) there was a history of diarrhoea at onset. Fifty-seven (78%) were managed by dialysis. Fifty (70%) of the 72 children had a favourable outcome with complete recovery, 3 (4%) died in the acute phase of the illness, 8 (11%) had residual hypertension or chronic renal failure, and 11 (16%) never recovered renal function. The probability of complete recovery of renal function was analysed by logistic regression which indicated that younger age, presentation in the summer months, diarrhoea at onset and, in those patients who were dialysed, a short prodromal illness were associated with a good outcome. Further analysis of the interaction among these variables in the patient group as a whole indicated that diarrhoea favoured a good outcome among boys but not girls.

Tissue resistance to 1,25-dihydroxyvitamin D without a mutation of the vitamin D receptor gene

OBJECTIVE

Hereditary vitamin D resistant rickets (HVDRR) is characterized by severe rickets and is often accompanied by alopecia. Mutations in the gene encoding the vitamin D receptor have been found in this condition. In a patient with the characteristic phenotype we have investigated the functional defect and sequenced the gene to seek a mutation.

DESIGN

Patient and control cell lines prepared from skin fibroblasts and peripheral blood lymphocytes were used to measure binding of 1,25(OH)2D3 and to isolate vitamin D receptor mRNA. VDR cDNA was sequenced and transfected into receptor defective cells.

PATIENT

A child with alopecia diagnosed as having rickets due to resistance to 1,25(OH)2D3.

MEASUREMENTS

Cytosolic binding and nuclear association of 1,25(OH)2D3 were determined in patient and control cells, and functional response to 1,25(OH)2D3 assessed by measurement of 24-hydroxylase activity. VDR mRNA was prepared, reverse transcribed, and cDNA sequenced. VDR cDNA was also transfected into VDR-deficient CV-1 cells and functional response to 1,25(OH)2D3 assessed by co-transfection with a chloramphenicol acetyltransferase (CAT) reporter plasmid.

RESULTS

VDR from the patient were able to bind 1,25(OH)2D3 but showed no nuclear localization resulting in an absence of functional response to 1,25(OH)2D3. Sequencing revealed that the VDR coding region was normal. Expression studies of the patient's VDR showed functionally normal VDR as evidenced by normal transactivation in the presence of 1,25(OH)2D3.

CONCLUSION

These data indicate a new cause of tissue resistance to 1,25(OH)2D3 which occurs in the absence of mutations in the coding region of VDR gene and which is characterized by defective nuclear localization of this receptor.

Plasma renin activity and aldosterone concentration in the human newborn

Twenty-one healthy newborn infants whose mothers had normal pregnancies and deliveries were studied. Plasma renin activity (PRA) and plasma aldosterone concentration (PAldo) were measured by semimicro methods in cord blood and on the 6th day of life. PRA and PAldo were increased in cord blood compared with values previously found in healthy infants between 1 month and 1 year of age. There was a twofold reduction in both values by the 6th day. PRA and PAldo were positively correlated when cord blood and 6th-day values were considered as a whole, but no significant correlations were found between either cord blood PRA or cord blood PAldo and their respective values on the 6th day. The PRA and PAldo findings were not related to birthweight, the infant's sex, weight change, 6th-day urinary sodium, or blood pressure measurements. The type of milk feed did not influence PRA but PAldo was slightly greater in bottle-fed babies on the 6 day. These observations confirmed that the inverse relationship between PRA, PAldo, and age extends into the neonatal period but they suggest that the balance of factors controlling these variables at birth is different to that operating at the age of 6 days.

Behçet's disease in UK children: clinical features and treatment including thalidomide

OBJECTIVE

To study the clinical spectrum of Behçet's disease (BD) in childhood, and to report our experience of using thalidomide.

METHOD

Ten children, diagnosed with BD, were studied retrospectively.

RESULTS

The median (range) age at first presentation was 4 (1.2-12.0) yr, at diagnosis was 11 (3-15) yr and the follow-up period was 4.1 (0.6-6.3) yr. Oral ulcers were present in all patients (100%), genital ulcers were present in six (60%), peri-anal ulcers were present in three (30%), skin manifestations were present in nine (90%), intracranial hypertension was present in two (20%), mild gastrointestinal symptoms were present in five (50%), joint symptoms were present in six (60%), ocular lesions were present in five (50%), but only one child had anterior and posterior uveitis. Therapeutically, a range of drugs was used, including colchicine, that resulted in good responses in five children. Thalidomide (1 mg/kg/week to 1 mg/kg/day) was used in five children who were unresponsive to other immunosuppressive agents. It resulted in complete remission in three children and less frequent milder oral ulcers in two. Neuropathy developed in two children and in one it was irreversible.

CONCLUSION

BD in children is similar to the disease in adults. Thalidomide provided a useful therapeutic option for severe oral and genital ulceration which was unresponsive to other therapies. Awareness of the danger of axonal neuropathy and teratogenesis at all times during thalidomide therapy is crucial. A low dose is probably as effective as higher doses.