Anti-neutrophil cytoplasmic antibodies in childhood systemic lupus erythematosus

The prevalence and antigen specificity of anti-neutrophil cytoplasmic antibodies (ANCA) in sera from 23 children with active systemic lupus erythematosus (SLE) were studied utilizing indirect immunofluorescence and IgG and IgM ELISA using crude neutrophil extract and purified proteinase 3, myeloperoxidase, lactoferrin, cathepsin G and elastase. ANCA were present in 69% of SLE children and consisted of IgM and IgG antibodies of variable specificities, but did not correlate with organ involvement or disease activity. It remains unclear whether they have pathogenic significance or are epiphenomena in the category of polyclonal B-cell activation. However, their presence is entirely compatible with SLE even though they have hitherto been commonly associated with other systemic vasculitides.

Alternative treatment to corticosteroids in steroid sensitive idiopathic nephrotic syndrome

A review was undertaken of the use of alternative immunosuppressive treatment in addition to corticosteroids in a cohort of 429 children with steroid sensitive nephrotic syndrome (SSNS) treated between 1980 and 1994. Two hundred and twenty two children (52%) received at least one course of alternative treatment, 98 (23%) two, and 43 (10%) three. Cyclophosphamide was administered to 196 children (46%); in 181 it was the first course of alternative treatment and in 104 (57%) of those it was also the last ('final course'). Levamisole was given to 56 children (13%) and cyclosporin to 53 (12%). Fifteen children in whom cyclosporin failed were treated with chlorambucil. A few patients received azathioprine or vincristine. Ten children developed secondary steroid resistance, of whom five progressed to chronic renal failure. Acute complications included reversible renal failure, septicaemia, peritonitis, convulsions, and cerebral thrombosis. There were three deaths. It is concluded that half of the referred children with SSNS were deemed to require at least one course of alternative immunosuppressive treatment, and that side effects of the treatment and complications of SSNS are infrequent but occasionally fatal.

Antiendothelial cell antibodies can be cytotoxic to endothelial cells without cytokine pre-stimulation and correlate with ELISA antibody measurement in Kawasaki disease

To confirm the presence of antiendothelial cell antibodies (AECA) and study the clinical value of their measurement in Kawasaki disease (KD), sera from patients with KD were assessed for binding to human umbilical vein endothelial cells (HUVEC) using a cellular based ELISA, and for complement-mediated cytotoxicity using 111In-labelled HUVEC. In the ELISA assay, IgM AECA were detected in 16/22 sera, whereas IgG AECA were only present in one out of 19 sera. There was a significant difference in IgM AECA titres when comparing patients with controls. Eight out of 16 sera showed cytotoxicity against HUVEC, and this was significantly enhanced when HUVEC were pretreated with tumour necrosis factor (TNF). IgM AECA titres measured by ELISA were positively correlated with their cytotoxicity. The findings suggest that IgM class AECA in sera from patients with KD are detectable by ELISA method, and that some of these antibodies, 50% in this study, can mediate complement-dependent cytotoxicity against endothelial cells.

Serum intact parathyroid hormone and ionised calcium concentration in children with renal insufficiency

We report our experience of the use of an immunoradiometric assay for intact parathyroid hormone (i-PTH) and the measurement of plasma ionised calcium concentration (PCa2+) in 73 children with chronic renal insufficiency (CRI); plasma creatinine concentration (PCr) 52-856 mumol/l. There was a poor correlation between i-PTH and PCr (r = 0.10, n = 552) compared with that for C-terminal PTH and PCr (r = 0.60, n = 248), suggesting that the i-PTH assay is independent of renal function in this group of treated children. A clear response of i-PTH to a low total plasma Ca (tPCa) and PCa2+ was observed. There was a significant positive correlation between both tPCa and PCa2+ (r = 0.50, n = 389) and the fraction of Ca2+ (the fraction of tCa which was ionised) and PCa2+ (r = 0.50, n = 389). The finding of a low or normal PCa2+ with a low calculated fraction of Ca2+ was frequently observed, i.e. the measured tPCa was unexpectedly high, suggesting complexing of Ca2+ by accumulated anions in CRI. There was a poor relationship between the plasma albumin concentration and both bound plus complexed Ca (tPCa minus PCa2+) and the fraction of Ca2+ (r = 0.15 and -0.17, respectively). The positive predictive value for a raised i-PTH of a tubular reabsorption of phosphate of less than 80% was 0.87, and of an alkaline phosphatase greater than 800 U/l was 0.37.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term cyclosporin A treatment of minimal-change nephrotic syndrome of childhood

We evaluated the efficacy of long-term cyclosporin A (CyA) treatment in the maintenance of remission in 40 children with steroid-dependent minimal-change nephrotic syndrome (MCNS). CyA was given in an initial dose of 5 mg/kg per day, adjusted to maintain a trough whole blood level of 50-150 ng/ml. All the 40 children received CyA for 1 year. In 18 patients, CyA was continued for a further period of at least a year without interruption; 9 patients had a second course of CyA therapy after an interval of at least 1 month. Of the 40 children 29 (72%) had one or more relapses during treatment with CyA, with 16 (40%) relapsing during the 1st year. During the second period of CyA, 10 (56%) of the 18 children treated continuously relapsed, whereas all the 9 children who had an interrupted course of therapy relapsed. CyA was discontinued at one time in 27 patients, all of whom subsequently relapsed, with a median time to relapse of 26 days. Long-term prednisolone in addition to CyA was required to maintain remission in 16 (40%) of the whole group. The results suggest that the long-term use of CyA is able to maintain remission of MCNS, although 40% of the patients also required low-dose alternate-day steroids; patients appeared to fare worse if the CyA course was interrupted; no patient experienced a long-term remission after CyA was stopped.

Effect of cyclosporin A on glomerular filtration rate in children with minimal change nephrotic syndrome

Cyclosporin A (CyA) is now commonly used in the management of children with steroid-dependent nephrotic syndrome. In order to assess nephrotoxicity related to CyA therapy, we measured glomerular filtration rate (GFR) on 123 occasions in 24 children with minimal change nephrotic syndrome receiving CyA. GFR was estimated from the plasma clearance of 51chromium-EDTA every 3 months during CyA therapy of up to 27 months duration. There was a significant reduction in GFR after 3 months of CyA therapy [118 +/- 33 (SD) to 93 +/- 24 ml/min per 1.73 m2] but no further fall thereafter, although the reduction in GFR was sustained for the duration of CyA therapy. This reduction in GFR appeared to be reversible upon cessation of CyA, but careful monitoring of renal function is necessary in such patients to prevent the development of longer term nephrotoxic sequelae.

Renovascular hypertension

Renovascular disease constitutes approximately 10% of cases of secondary hypertension in childhood. It is associated with neurofibromatosis and a number of other syndromes. Fibromuscular dysplasia is the commonest histopathological finding. Bilateral and intrarenal disease is common and is associated with extrarenal arterial disease in a significant proportion of cases. Utilizing currently available investigative procedures, the nature of the disease can be defined and decisions made regarding appropriate treatment. However, although there is the potential for surgical cure, a substantial number of children still require medical therapy probably due to the high incidence of bilateral and small intrarenal arterial involvement that is not amenable to surgical or angioplasty treatment.

Lymphocyte subpopulations, interleukin-2 and interleukin-2 receptor expression in childhood nephrotic syndrome

Abnormal T lymphocyte function and reduced interleukin-2 (IL-2) production have been implicated in the pathogenesis of the nephrotic syndrome (NS). We investigated: (1) lymphocyte subpopulations and expression of IL-2 receptor (IL-2R) on T cells using two-colour flow cytometry, (2) serum IL-2 and (3) the soluble component of IL-2R (sIL-2R) in serum, using enzyme-linked immunosorbent assay, in 38 children with NS. All children, except those in remission, had marked proteinuria. They were divided into groups according to renal pathology: (1) steroid-sensitive NS (SSNS) not receiving prednisolone therapy, (2) SSNS on prednisolone, (3) focal segmental glomerulosclerosis (FSGS), (4) SSNS in remission and not receiving prednisolone therapy, (5) congenital NS (CNS). Results were compared with 26 age-matched controls. Total T lymphocytes (CD3) were reduced in groups 1 and 2; CD4 count was reduced in groups 1-4; CD8 count increased in groups 2 and 3; CD8 and CD19 (B lymphocytes) were significantly reduced in group 5. Increased IL-2R expression (CD25) on CD4 lymphocytes was noted in groups 1, 2 and 3 implying activation of these cells. In patients with SSNS, increased serum sIL-2R was recorded during relapse (1,273 +/- 497 U/l vs. 913 +/- 401 U/l in remission, P < 0.005) but free serum IL-2 was not detectable at any stage. The specific alterations in lymphocyte subpopulations in SSNS and FSGS would imply an involvement of the immune system distinct from that in CNS.

Chronic rash associated with congenital rubella

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Sodium-lithium countertransport and family history of hypertension in childhood

We have studied the relationship between sodium-lithium countertransport, determined in childhood, and family history of hypertension. Countertransport was measured in healthy children and those with secondary hypertension. There was no significant difference in countertransport between these two groups. In the normal children (n = 52, median age 6.8 years), there was a positive relationship between body mass index and countertransport (rs = 0.34, p < 0.02). A positive relationship between family history of hypertension using a ranked scoring system, and countertransport, not related to age, body mass or blood pressure (n = 34, rs = 0.63, p < 0.001) was also found. There was no significant relationship between intracellular sodium concentration and countertransport. These data confirm that countertransport in normal children is related to body mass index and indicate that a genetic predisposition to primary hypertension marked by sodium-lithium countertransport is identifiable in childhood.

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.

Cystic fibrosis presenting as kwashiorkor with florid skin rash

Two infants with a florid erythematous rash and generalised oedema, hypoalbuminaemia, and anaemia were found to have cystic fibrosis. This rare presentation is associated with false negative sweat tests, delays in diagnosis, and a considerable mortality. It is proposed that this presentation represents a manifestation of kwashiorkor secondary to malabsorption. The recognition that these infants have kwashiorkor provides some insight into the pathogenesis and management of their illness.

Tubular proteinuria in steroid sensitive multi-relapsing nephrotic syndrome

The urinary excretion of N-acetyl-beta-D-glucosaminidase (UNAG) and retinol binding protein (URBP) was studied in 65 children with steroid sensitive multirelapsing nephrotic syndrome (MRNS): 28 on cyclosporin A (CyA) therapy, 22 on prednisolone (P), 15 off-treatment and in 32 normal children to assess renal tubular damage or dysfunction. The urinary protein excretion was expressed in relation to that of creatinine (UNAG/UC in mumol pnp/h/mmol; URBP/UC in microgram/mmol). There was a weak but significantly negative correlation between age and both, UNAG/UC (r = -0.38, p < 0.01) and URBP/UC (r = -0.50, p < 0.05) in normal children, but not in nephrotics. In normals and in patients off steroids an association between these two proteins was found (r = 0.38, p < 0.05; r = 0.56, p < 0.05 respectively). Geometric mean UNAG/UC was significantly higher in nephrotics on CyA therapy (26.5 +/- 4.0), and on P (37.0 +/- 7.9) as well as in those off-treatment (16.3 +/- 3.1) compared to normal children (9.3 +/- 3.4). There was a further increase in those with raised urinary albumin: creatinine ratio (UA/UC) (> 0.1 mg/mg). URBP/UC was not increased in any of the groups of children with MRNS. Raised NAG in urine may therefore indicate active nephrotic syndrome rather than being due to the drug therapy.

Systemic vasculitis

The systemic vasculitides are comparatively rare but important disorders of childhood. Apart from Henoch-Schönlein purpura, which is the commonest example in paediatric practice, Kawasaki disease is most often encountered. Polyarteritis and Wagener's granulomatosis have a lower incidence but are associated with a high morbidity and mortality. Newer investigative procedures and therapeutic approaches have led to more accurate diagnoses and improved outcome but further advances await a better understanding of the vasculitides: polyarteritis; Kawasaki disease; Wagener's granulomatosis; and ANCA in childhood.

Atypical (non-diarrhea-associated) hemolytic-uremic syndrome in childhood

We describe the clinical and laboratory features of 20 children who were seen during the past 20 years with idiopathic nondiarrhea-associated hemolytic-uremic syndrome. There was no seasonal variation in time of onset; a genetic pre-disposition seemed likely in two of the cases. The prodromal illness was nonspecific and by definition did not include diarrhea. Hypertension was a major problem in the majority of the patients. Five died, three during the initial illness; four are in end-stage renal failure, and all but two of the survivors have residual nephropathy. Eleven patients had a "relapsing" course; up to eight additional documented episodes of hemolytic-uremic syndrome occurred in individual patients. Of the nine children treated before 1980, three died shortly after onset, two never recovered function after the initial illness, one had a relapsing course and died later, and one had residual nephropathy. Plasma exchange was introduced for the management of non-diarrhea-associated hemolytic-uremic syndrome in 1980; since then, all of the 11 patients have recovered function after the initial episode, but 10 of them had relapses. It appears that with the introduction of plasma exchange there has been an improved outcome in the initial phase, but the survivors tend to have relapses. Atypical (non-diarrhea-associated) hemolytic-uremic syndrome is a heterogeneous yet distinct subgroup of hemolytic-uremic syndrome that differs from diarrhea-associated hemolytic-uremic syndrome on epidemiologic, clinical, laboratory, histologic, and prognostic grounds.

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.

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.

A measles virus isolate from a child with Kawasaki disease: sequence comparison with contemporaneous isolates from 'classical' cases

We examined the relationship between a measles virus isolate from a child with Kawasaki disease and two contemporaneous wild-type isolates from children with 'classical' measles and the Schwarz vaccine strain. Sequence analysis of 3118 bp from the nucleoprotein, matrix, fusion and haemagglutinin genes of each virus revealed that the isolate from the child with Kawasaki disease was not related to measles vaccine strains and did not contain any of the marked abnormalities previously found in subacute sclerosing panencephalitis isolates, but was more akin to wild-type isolates currently circulating in the U.K. A comparison of our sequences with those obtained from earlier wild-type U.K. isolates suggests significant evolution of measles virus in the U.K. over the last decade.

Mesangiocapillary glomerulonephritis associated with meningococcal meningitis, C3 nephritic factor and persistently low complement C3 and C5

We report two unusual cases in which mesangiocapillary glomerulonephritis occurred in association with meningococcal infection. C3 nephritic factor, an autoantibody to alternate pathway C3 convertase, was present. Low serum complement C3 and C5 levels were also noted. The depressed complement levels, in conjunction with terminal complement complexes at the upper limit of normal, suggest activation of the early and late complement cascade. We suggest that children presenting with meningococcal infection should have a regular urine examination, as well as full complement measurements performed, in view of the association with hypocomplementaemic mesangiocapillary glomerulonephritis. Similarly, prophylactic penicillin should be prescribed for patients with mesangiocapillary glomerulonephritis and persistently low C5 levels to prevent meningococcal complications.

Crescentic glomerulonephritis in children

Data on patients with crescentic glomerulonephritis (greater than 50% glomeruli with crescents), referred to the Hospital for Sick Children during the past 13 years, were reviewed. Thirty patients (13 male, 17 female) aged 3.7-15.7 years (mean 9.5) were evaluated. Initial clinical features included: oedema (24/30), hypertension (19/30), gross haematuria (15/30), oliguria (15/30) and a decreased glomerular filtration rate (GFR less than 30 ml/min per 1.73 m2) (22/30). Henoch-Schönlein purpura was present in 9 patients, microscopic polyarteritis in 3, polyarteritis nodosa in 1, Wegener's granulomatosis in 1, systemic lupus erythematosus in 1, post-streptococcal glomerulonephritis in 2, mesangiocapillary glomerulonephritis in 7, anti-glomerular basement membrane glomerulonephritis in 2, and 4 were idiopathic. In 10 patients 50%-79% of glomeruli were affected by crescentic changes (group 1) and in the remaining 20, 80% or more (group 2). The crescents were cellular, fibrocellular or fibrous, and the degree of sclerosis was assessed. Patients in both groups were treated with plasma exchange, corticosteroids, anticoagulants, cyclophosphamide and azathioprine in different combinations. On follow-up, 3 patients were dead, 1 was lost to follow-up, 12 were on dialysis/transplant programmes, 4 had a GFR of less than 30 and 10 a GFR of more than 30 ml/min per 1.73 m2. In our experience, 50% progressed to end-stage renal failure. The interval between disease onset and start of treatment was a prognostic factor for outcome. Fibrous crescents were associated with a worse outcome than fibrocellular crescents (P less than 0.05). Outcome was not, however, related to the percentage of glomeruli affected (P greater than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Cadaveric renal transplantation in children under 5 years of age

From March 1987 to August 1990 23 cadaveric renal transplants were performed in 19 children under the age of 5 years at the time of transplantation. The mean age of the recipients was 3.3 years (range 1.3-4.7) and the mean weight 13.0 kg (range 9.3-19.2). The mean donor age was 7.8 years (range 1.5-25). All children received triple immunosuppression with prednisolone, cyclosporin A and azathioprine, and 4 who had 2 grafts during this period also received antithymocyte globulin at the time of the second transplant. Patient survival is 100%. Actuarial first cadaveric graft survival was 57% at 1 year and remains unchanged at 3 years. There were 10 graft losses, 4 were associated with renal venous thrombosis without apparent rejection. Two were lost due to acute vascular rejection with associated renal venous thrombosis, and the remaining 4 losses followed cellular or chronic vascular rejection. The mean glomerular filtration rate +/- SD was 51.4 +/- 23.6 ml/min per 1.73 m2 (n = 11) at 1 year and 43.5 +/- 25.3 at 2 years (n = 6). The mean height standard deviation score improved from -2.2 +/- 1.1 at the time of transplantation to -1.3 +/- 1.0 1 year post transplant (n = 11). The immunosuppression was well tolerated with a low incidence of side effects. Cadaveric renal transplantation remains a difficult but rewarding undertaking in children under 5 years of age.

Neutrophil activation in the haemolytic uraemic syndrome: free and complexed elastase in plasma

There is evidence of neutrophil involvement in the pathogenesis of the haemolytic uraemic syndrome (HUS), and neutrophil release products are thought to cause endothelial cell damage. Elastase is the major lysosomal proteinase liberated by activated neutrophils. In this study we measured both free and complexed elastase. No free elastase activity could be detected in the plasma of patients with diarrhoea-associated (D+) HUS using a specific substrate. However, there was a marked increase in alpha 1-antitrypsin (alpha 1-AT) complexed elastase as measured by a newly developed enzyme-linked immunosorbent assay not only in D+ HUS, but also in non-diarrhoea-associated (D-) HUS. This finding is independent of either a high polymorphonuclear leucocyte count or renal failure. This increase in bound elastase together with our sequential data which demonstrate raised alpha 1-AT complexed elastase levels early in the disease process further support the theory that neutrophil activation is one of the key events in the pathophysiology of this disorder.