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.

Association of parvovirus B19 infection with idiopathic collapsing glomerulopathy

BACKGROUND

Collapsing glomerulopathy (CG), a disorder with severe glomerular and tubular involvement, occurs either as an idiopathic lesion or in some patients with human immunodeficiency virus (HIV) infection known as HIV-associated nephropathy (HIVAN). We previously reported a renal transplant recipient with de novo CG and red cell aplasia in association with persistent parvovirus B19 (PVB19) infection. This prompted us to look for an association between PVB19 infection and CG.

METHODS

DNA from archived biopsies of patients with CG was analyzed for PVB19 by polymerase chain reaction (PCR). Results were compared with HIVAN, idiopathic focal segmental glomerulosclerosis (FSGS), and controls. In situ hybridization (ISH) was done to localize PVB19 in renal biopsies. Peripheral blood specimens of patients with CG, HIV infection, healthy controls, and randomly selected hospitalized patients (sick controls) were also analyzed for PVB19.

RESULTS

PVB19 DNA was detected in renal biopsies of 18 out of 23 (78.3%) patients with CG, 3 out of 19 (15.8%) with HIVAN, 6 out of 27 (22.2%) with FSGS, and 7 out of 27 (25.9%) controls (P < 0.01, CG vs. HIVAN, FSGS, and controls). PVB19 was detected in peripheral blood of 7 out of 8 (87.5%) CG patients, 3 out of 22 (13.6%) with HIV infection, 4 out of 133 (3%) healthy controls, and 2 out of 50 (4%) sick controls (P < 0.001, CG vs. HIV infected, healthy, and sick controls). PVB19 was identified in glomerular parietal and visceral epithelial and tubular cells by ISH.

CONCLUSIONS

The significantly higher prevalence of PVB19 DNA in renal biopsies and peripheral blood of CG patients suggests a specific association between PVB19 infection and CG. In susceptible individuals, renal epithelial cell infection with PVB19 may induce CG.

Parvovirus B19 infection-related complications in renal transplant recipients: treatment with intravenous immunoglobulin

BACKGROUND

Chronic red cell aplasia can develop in immunocompromised patients including transplant recipients infected with parvovirus B19 (PV B19). Renal involvement with PV B19 infection is not well-recognized.

METHODS

We diagnosed erythroid hypoplasia associated with PV B19 infection in three renal transplant recipients; one of them developed de novo collapsing glomerulopathy. These patients were treated with intravenous immunoglobulin (IVIG).

RESULTS

In two patients, anemia responded promptly to IVIG therapy. One of them had recurrence of anemia that responded to a second course of IVIG. Despite IVIG treatment, persistent infection with PV B19, recurrent anemia, and de novo collapsing glomerulopathy leading to allograft failure developed in the third patient, who had received the most intense immunosuppression.

CONCLUSIONS

These findings indicate that PV B19 infection in transplant recipients can cause chronic red cell aplasia that generally responds to IVIG therapy. In some patients, particularly those who are heavily immunosuppressed, infection may persist despite treatment. As the cellular receptor for PV B19 is expressed in the kidney, persistent infection may result in development of glomerulopathies in these patients.

Prolonged versus standard prednisolone therapy for initial episode of nephrotic syndrome

We have examined, in a prospective randomized controlled trial, the effect of 8- and 16-week initial steroid treatment on the course of idiopathic nephrotic syndrome (INS). Patients with a first episode of INS were randomized to receive standard 8-week prednisolone (2 mg/kg daily for 4 weeks, then 1.5 mg/kg on alternate days for 4 weeks) or prolonged 16-week prednisolone treatment (2 and 1.5 mg/kg daily each for 4 weeks, then 1.5 and 1 mg/kg on alternate days each for 4 weeks). Relapses were treated with prednisolone, 2 mg/kg daily for 2 weeks, then 1.5 mg/kg on alternate days for 4 weeks. Of 45 patients, 23 received standard therapy and 22 prolonged therapy. The mean duration of follow-up was 29.2 and 27.3 months in the standard and prolonged treatment groups, respectively. The time to first relapse was longer in the prolonged treatment (mean 222.2 days, median 120.0 days) than the standard group (mean 134.3 days, median 96.5 days). The percentage of patients with no relapse at 6 and 12 months after prednisolone withdrawal was 40.9% and 27.3% in the prolonged treatment and 21.7% and 8.7% in the standard groups, respectively. The inability to show statistically significant differences between the two groups was probably related to the small number of patients studied. Prolonged therapy did not affect the subsequent relapse rates and proportion of patients with frequent relapses and steroid dependence. The mean dose of prednisolone received, for the initial episode and relapses during the next year, was higher and associated with significant steroid toxicity in the prolonged treatment group. Our findings suggest that 16-week prednisolone treatment for the initial episode of INS may delay occurrence of the first relapse, but results in significant side effects. Prolongation of initial therapy may be useful in developing countries where frequent infections often induce early relapses.

Lung allograft dysfunction correlates with gamma-interferon gene expression in bronchoalveolar lavage

BACKGROUND

Preceding episodes of acute cellular rejection (ACR) may predispose lung allografts to the subsequent development of irreversible dysfunction or bronchiolitis obliterans syndrome (BOS). Other histologic patterns such as bronchiolitis obliterans with organizing pneumonia (BOOP), organizing pneumonia, lymphocytic bronchiolitis and diffuse alveolar damage (DAD) may also adversely affect allograft function. We have previously reported the predominant expression of Th1 cytokines (IL-2 and interferon gamma) in rejecting and Th2 (IL-10) in a tolerant model of rat lung transplantation. Here we correlate the "Th1/Th2 paradigm" in clinical lung transplantation with histologic findings and assess the effect on serial spirometric function.

METHODS

We examined the mRNA expression of IL-2, interferon gamma, IL-10 and ICAM-1 in 53 bronchoalveolar lavage (BAL) specimens from 23 lung transplant (LT) recipients utilizing qualitative "nested" reverse transcriptase polymerase chain reaction (RT-PCR). We also measured IgG1 and IgG2 levels in 44 BAL specimens by ELISA. The mRNA expression for cytokines, ICAM-1 and the IgG2/IgG1 ratios were correlated with the presence or absence of ACR and alternate "histologic patterns". Serial spirometry were analyzed for the 2-3 month interval before bronchoscopic (FOB) assessment to derive "baseline" forced expiratory volume-one second (FEV1) values. The change in FEV1 coincident with (deltaFEV1 pre) and for the 2-3 month interval subsequent to (deltaFEV1 post) FOB were expressed relative to "baseline" spirometric indexes.

RESULTS

Detection of mRNA for interferon gamma and ICAM-1 correlated significantly with ACR, whereas IL-2 and IL-10 expression did not correlate. IL-10 was virtually "ubiquitous" in most BAL samples irrespective of the presence or absence of ACR. The highest correlation was observed with interferon gamma for acute cellular rejection whereupon the sensitivity was 77.7%, specificity 87.7%, positive predictive value 73.6% and negative predictive value 88.2%, although for ICAM-1 these values were 75%, 65.7%, 50.0% and 85.0%, respectively. Nevertheless, 4 of 5 episodes of respiratory tract infection (bacterial, CMV, Aspergillus spp.) were similarly associated with cytokine mRNA. The ratios of IgG2 to IgG1, a reflection of Th1/Th2 influence, were not statistically different when analyzed for the presence or absence of ACR (0.91+/-0.53 vs. 1.02+/-0.70, respectively; p = NS). By analysis of FEV1 trends, expression of interferon gamma was associated with a greater and persistent decrement (deltaFEV1 pre: -0.265+/-0.78 liters, and post: -0.236+/-0.1161; mean +/- SE) than ACR in the absence of interferon gamma expression (+0.158 +/- +0.065 and +0.236+/-0.007 liters, respectively) (Student-Newman-Keuls, p<.05).

CONCLUSION

Our findings suggest that interferon gamma mRNA expression and ICAM-1 may be valuable in both the diagnosis and prognosis for lung allograft ACR. IL-10, a Th2 cytokine, was locally expressed both in the presence and absence of ACR. Expression of mRNA for interferon y in BAL and, to a lesser extent ICAM-1, were associated with increased lung allograft dysfunction. Whether BAL cytokine "immunosurveillance" would complement or possibly supplant a specific "histologic pattern" and thereby direct different therapies after lung transplantation, may be potentially rewarding areas of further investigation.

Levamisole therapy in corticosteroid-dependent nephrotic syndrome

The effect of prolonged treatment with levamisole was examined in 43 patients (30 boys) with steroid-dependent nephrotic syndrome (SDNS). The mean age at institution of treatment was 4.0 +/- 2.0 years. Fourteen patients had previously received cyclophosphamide with an ensuing remission of 8.5 +/- 10 months. Following induction of remission with prednisolone, levamisole was administered at a dose of 2.5 mg/kg body weight on alternate days. Prednisolone was tapered by 2.5-5 mg every 4 weeks to 0.5 mg/kg on alternate days. The duration of levamisole therapy ranged from 6 to 31 months (mean 17.4 +/- 8.4 months); 15 patients received levamisole for more than 18 months and 10 for more than 24 months. Prednisolone was discontinued in 18 patients after a mean duration of 11.7 +/- 7.1 months, whereas in 21 patients its dose was reduced to 0.2-0.4 mg/kg on alternate days. The mean relapse rate prior to levamisole therapy was 3.0 +/- 1.5 relapses/year, which reduced to 0.9 +/- 0.7 relapses/year during levamisole treatment (P < 0.001). A comparison of the response in 14 patients who had previously received cyclophosphamide with the other 29 patients did not show any significant difference. There were no side effects of levamisole therapy. Our findings suggest that prolonged treatment with levamisole is beneficial and safe in SDNS, with a marked steroid-sparing effect. A significant proportion of these patients can be kept in remission on levamisole alone.

T cell Vbeta repertoires in childhood vasculitides

Superantigens (SAgs) are potent stimulators of T cells bearing specific Vbeta T cell receptors (TCR) and may play a role in the aetiopathogenesis of systemic vasculitis, although this remains contentious. To investigate the possible aetiological role of SAgs, this study examined peripheral blood T cell Vbeta repertoires in children with systemic vasculitis. FACS analysis of 17 different peripheral blood T cell Vbeta families was performed in 20 healthy control children, 27 disease control children with nonvasculitic inflammatory disease, 25 children with primary systemic vasculitis, six patients with Kawasaki disease (KD) and six patients with Henoch-Schönlein purpura (HSP). There was a significantly increased variance of CD4 Vbeta12 and Vbeta17, and CD8 Vbeta1 in the primary systemic vasculitis group compared to control and disease controls. Moreover, 80% of the primary systemic vasculitis children had one or more CD4 Vbeta expansions or deletions, compared with 30% of controls (P < 0.002), and 37% of the disease controls (P < 0.002). In the KD group, the mean percentage of CD4 Vbeta2 T cells was higher than in controls or disease controls. In the HSP group, there was no consistent skewing of the T cell Vbeta repertoire. We have observed changes in the T cell Vbeta repertoire in children with vasculitis over and above those observed in disease controls. While these data provide impetus for further research into this contentious field, they do not resolve unequivocally the question of the role of SAgs in childhood vasculitic syndromes.

Expression of gamma-IFN mRNA in bronchoalveolar lavage fluid correlates with early acute allograft rejection in lung transplant recipients

Various cytokines are upregulated in acute allograft rejection (AR). Local production of Th-1 cytokines is suggested to play a pathogenic role in AR, and Th-2 cytokines in the development of allograft tolerance. The purpose of this study was to correlate the expression of Th-1 [interleukin-2 (IL-2) and gamma-interferon (gamma-IFN)], and Th-2 [interleukin-10 (IL-10)] cytokines in bronchoalveolar lavage (BAL) fluid with AR in lung transplant (LT) recipients. The role of Th-1 dominance expressed as IgG2/IgG1 ratio in BAL in AR was also examined. The mRNA expression for IL-2, gamma-IFN and IL-10 was examined in 64 BAL specimens from 23 LT recipients using reverse transcriptase-polymerase chain reaction (RT-PCR). IgG1 and IgG2 levels were measured in 55 BAL specimens by enzyme-linked immunosorbent assay (ELISA). The expression on mRNA for these cytokines, and the ratio of IgG2/IgG1 was correlated with AR (early AR occurring within 3 months of transplant and late AR occurring after 3 months). Ten patients had 17 episodes of biopsy proven AR. Twelve episodes of AR (6 patients) occurred within the first 3 months of transplantation. In 5 patients, AR was diagnosed 4, 5, 6, 9 and 24 months post-transplantation. Detection of gamma-IFN mRNA correlated significantly with early AR (p < 0.001), whereas it lacked correlation with late AR. Expression of IL-2 and IL-10 mRNA did not correlate with AR. IL-10 was present in most samples irrespective of the presence or absence of AR. The ratio of IgG2/IgG1 was similar in patients with or without AR. Our findings suggest that the detection of gamma-IFN mRNA in BAL by RT-PCR is useful for immune monitoring of early AR in LT recipients. Absence of elevated IgG2/IgG1 ratio, and presence of IL-10 in BAL during AR suggests that Th-1 cytokines may not be the sole mediator of rejection in LT recipients.

Outcome of lupus nephritis in Indian children

We report the clinicopathological features, treatment and outcome of 54 Indian children (14 boys) with biopsy-proven lupus nephritis followed over a 10-year period. The mean age (SD) at onset of disease was 9.6 ± 2.6 (range 2.5–14.4) years. Twenty-six (48.1%) patients had class IV nephritis, 7 (13.0%) had class V, whereas class I, II and III nephritis were present in 3 (5.6%), 10 (18.5%) and 6 (11.1%) patients, respectively. Hypertension, haematuria and nephrotic range proteinuria were present in 30 (55.6%), 31 (57.4%) and 28 (51.8%) patients, respectively. Compared with all the other classes combined, there were more boys among patients with class IV nephritis, and hypertension, haematuria, nephrotic syndrome and decreased glomerular filtration rate at presentation were more common. The mean duration of follow-up was 3.1 ± 2.9 years (median 2.5, range 0.2–10.3 years). Of the 39 patients who were followed-up for at least 1 year, 33 (84.6%) were in complete or partial remission, whereas six (15.4%) had no response to therapy. The incidence of serious infection was 1.5 episodes per 10 patient-years. Nine patients died, of whom four had serious infections or septicaemia, and three developed end-stage renal failure (ESRF). The patient survival rate at 3 years and at last follow-up visit was 88% and 83.3%, respectively, whereas the renal survival rates (without ESRF) were 92% and 94.4% respectively. Cox regression analysis showed no relation of gender, age of onset, presence of hypertension, haematuria and proteinuria, estimated glomerular filtration rate, renal histology and response to therapy to the outcome of death or ESRF. We found lower patient survival rate as compared with data from the developed countries but similar to that seen in developing countries. Serious infections were an important cause of mortality besides renal failure.

Hemolytic uremic syndrome in children in northern India

We observed 73 patients with the hemolytic uremic syndrome (HUS) in 9 years (1980-1988), comprising 34% of patients with acute renal failure treated over the same period. There were 53 boys and 20 girls; 59% were below the age of 2 years and 33% between 2 and 5 years. Acute, usually severe dysentery, responding poorly to various antibiotics, was the prodromal illness in 80%, whereas 12% had watery diarrhea. Most patients had severe renal involvement with anuria in 56% and oliguria in 30%. A polymorphonuclear leukocytosis was present in 85% of cases, but had no correlation with the highest levels of blood urea. Coagulation abnormalities suggesting consumption coagulopathy were found in 24 of 30 cases. The results of stool culture showed Shigella species in 7 cases and nontyphoidal Salmonella in 9. Escherichia coli were isolated in 11 cases, but were not further characterized. Renal biopsy showed total or patchy cortical necrosis in 20 of 50 cases. The patients were managed with supportive care, including transfusion of fresh blood or plasma and dialysis as required. The mortality was 60%, being chiefly related to the duration of renal failure and presence of renal cortical necrosis, whereas persistent dysentery and infections were complicating factors. The presence of convulsions and coagulation defects had no relation to the outcome. Our observations indicate that HUS in children in northern India is mostly related to dysentery, likely to be shigellosis, and is usually associated with severe renal damage and a high death rate.

Treatment of focal glomerulosclerosis with pulse steroids and oral cyclophosphamide

Patients with steroid-resistant nephrotic syndrome often have an unsatisfactory long-term outcome and are at risk of developing chronic renal failure. We prospectively treated 65 children with idiopathic steroid-resistant nephrotic syndrome and focal segmental glomerulosclerosis (FSGS) with intravenous pulses of corticosteroids and oral cyclophosphamide. Dexamethasone (5 mg/kg) or methylprednisolone (30 mg/kg) was administered intravenously, initially 6 pulses on alternate days, followed by 4 fortnightly and 8 monthly pulses. Oral cyclophosphamide therapy was given for 12 weeks and tapering doses of prednisolone were administered for 52 weeks. The mean age at treatment was 85.7+/- 44.9 months. Five patients developed serious infections during administration of initial alternate-day pulses and were excluded. Of 59 patients who completed initial alternate-day therapy, 17 had complete and 8 partial remission; 34 (57.6%) patients did not respond to treatment. The median urine protein to creatinine ratio decreased from 10.0 to 0.75 (P<0.005) and serum albumin increased from 1.9 g/dl to 2.4 g/dl (P<0.01). The median duration of follow-up after stopping pulse therapy was 25.6 months. Thirty-four patients were followed for more than 3 years (median 4.5 years). Of these, 22 (64.7%) patients had a favorable outcome; persistent complete remission was seen in 15 patients and steroid-responsive relapses in 7. Seven patients had non- nephrotic-range proteinuria, 2 had nephrotic-range proteinuria, and 3 (8.8%) were in chronic renal failure. There was no significant difference in the short- and long-term outcome of patients with initial (n=28) and late resistance (n=31). The outcome in patients receiving intravenous dexamethasone (n=48) or methylprednisolone (n=11) was also similar. The chief side effects included worsening of height standard deviation score (47.4%), transient hypertension (42.5%), and serious infections (18.5%). We conclude that prolonged treatment with intravenous corticosteroids and oral cyclophosphamide is beneficial in patients with steroid-resistant FSGS. Expensive protocols can be successfully modified and used, depending upon the availability of health resources.

Single- versus divided-dose prednisolone therapy for relapses of nephrotic syndrome

Relapses of nephrotic syndrome are usually treated with prednisolone, initially in three to four daily divided doses. The divided-dose regimen may cause poor patient compliance and greater adrenal suppression. In a prospective randomized controlled trial, we compared the efficacy of prednisolone in inducing remission of nephrotic syndrome, when given either as a single dose or in divided doses. Patients with steroid-responsive nephrotic syndrome with relapse were randomized to receive prednisolone 2 mg/kg per day, either as a single morning dose or in three divided doses for 2 weeks, followed by 1.5 mg/kg on every alternate day for 4 weeks. Parents tested the urine for protein daily until remission (nil proteinuria for 3 consecutive days). The duration between initiation of treatment and achievement of remission was recorded. Of 106 patients, 94 (47 each in single-dose and divided-dose groups) completed the study. The patients in the two groups were similar in relation to age, sex, number of relapses in the preceding year, and blood levels of creatinine, albumin, and cholesterol. The mean time for achievement of remission in the single- and divided-dose groups was 8.6 and 8.5 days, respectively (P = 0.94, power 96%). After 9 months' follow-up, there were no differences in the frequency of relapses and cumulative dose of prednisolone received in the two groups. The observations suggest that prednisolone administered in a single daily dose or in divided doses is equally effective in inducing remission in patients with relapsing nephrotic syndrome.

Intracranial tuberculoma. Evaluation and treatment

We used computerized tomography (CT) to screen 83 patients with partial seizures who had 1) increased intracranial pressure; 2) evidence of systemic tuberculosis; or 3) focal neurological deficit. We found intracranial tuberculoma in 20 (24%). In addition, of 55 patients with tuberculous meningitis, 12 had associated tuberculoma. The image morphology on CT scans showed ring lesions (14), discs (10), and irregular coalescing masses (8). Perilesional edema frequently was present. After appropriate antitubercular therapy, clinical outcome for seizures, neurological deficit, and increased intracranial pressure was satisfactory. CT lesions regressed within 12 weeks of inauguration of medical therapy in most patients. Medical management of tuberculoma is advocated, with surgery limited to those in whom such treatment is ineffective.

Crescentic glomerulonephritis in children: a review of 43 cases

Forty-three children with crescentic glomerulonephritis (GN), having large crescents in more than 50% of the glomeruli, were observed during a period of 22 years. There were 17 boys and 26 girls between the ages of 3.5 and 14 years (mean 8.7 +/- 2.6). Thirty-one patients (72%) presented with acute nephritic features and increasing renal insufficiency (rapidly progressive GN) whereas 12 had an insidious onset with nephrotic syndrome, or rarely with nonspecific symptoms. Eleven patients had evidence of poststreptococcal GN and 6 an underlying systemic disorder. Renal biopsy showed large crescents in greater than 80% of the glomeruli in 38 cases (100% in 28) which were predominantly fibrocellular or fibrous in 80% of the patients. Nineteen patients (44%) were treated with prednisolone, cyclophosphamide and dipyridamole; in addition, 8 were also given anticoagulants. Six patients received pulse doses of corticosteroids. In 23 patients, there was inexorable progression of renal failure, 14 showed partial improvement but subsequently had varying degrees of renal insufficiency and in 6, there was recovery of renal function with normal levels of serum creatinine. Of the latter, 4 had received immunosuppressive anticoagulant therapy and 2 only supportive care. Of 11 patients with poststreptococcal crescentic GN, 7 progressed to end-stage renal disease and 2 developed chronic renal insufficiency. Our findings confirm the poor outcome of crescentic GN in children, irrespective of the underlying etiology. In a small proportion of cases, the disorder may have an insidious onset and a slowly progressive course, but an equally grave prognosis.

Gastric residuals in preterm babies

The gastric residual (GR) volume was measured in 50 healthy preterm babies, 38 appropriate-for-dates (AFD), and 12 small-for-dates (SFD) with gestational age of 28-36 weeks. The mean basal 4-hour gastric residual (B4 GR) volume was 2.8 +/- 0.63 ml in parenterally fed babies. There was a marked decrease in the residuals from 20.7 +/- 15.2 per cent (mean +/- SD) on day 4 to 8.6 +/- 4.3 per cent on day 7 (P < 0.001). Of the 27 infants fed with expressed breastmilk (EBM), mean GR was 24.4 +/- 10.2 per cent in supine and 12.8 +/- 4.3 per cent in prone position (P < 0.01). Twenty-one babies nursed in the prone position showed a mean GR volume of 12.8 +/- 4.3 per cent with EBM and 13.6 +/- 2.7 per cent with milk formula. No difference was noted in the gastric residuals of AFD v. SFD babies. No linear correlation was found between increase in abdominal girth and GR. However, if the increase in abdominal girth was at least 2 cm or more, a GR of 23 per cent or more was observed. This should be taken as warnings to reduce or withhold oral feeds.

Nephronophthisis associated with Ellis-van Creveld syndrome

Ellis-van Creveld (EvC) and Jeune's asphyxiating thoracic dystrophy (ATD) are related disorders characterized by narrow thoracic cage and short-limbed dwarfism. Some patients have overlapping features of both ATD and EvC, indicating that these syndromes may be a part of a disease spectrum. Nephronophthisis has been occasionally reported in patients with ATD, but not with EvC syndrome. We report a patient who was diagnosed with EvC syndrome at birth. He developed hypertension at 5 months of age and gradually progressive renal failure, requiring renal transplantation at 8 years. Histopathological findings in the nephrectomy specimen were indicative of nephronophthisis. The association of nephronophthisis in a patient with EvC syndrome has not been reported previously. This association further supports the hypothesis that ATD and EvC syndromes are related and represent a spectrum of disorders.

Influenza A virus reassortment in mammals gives rise to genetically distinct within-host subpopulations

Influenza A virus (IAV) genetic exchange through reassortment has the potential to accelerate viral evolution and has played a critical role in the generation of multiple pandemic strains. For reassortment to occur, distinct viruses must co-infect the same cell. The spatio-temporal dynamics of viral dissemination within an infected host therefore define opportunity for reassortment. Here, we used wild type and synonymously barcoded variant viruses of a pandemic H1N1 strain to examine the within-host viral dynamics that govern reassortment in guinea pigs, ferrets and swine. The first two species are well-established models of human influenza, while swine are a natural host and a frequent conduit for cross-species transmission and reassortment. Our results show reassortment to be pervasive in all three hosts but less frequent in swine than in ferrets and guinea pigs. In ferrets, tissue-specific differences in the opportunity for reassortment are also evident, with more reassortants detected in the nasal tract than the lower respiratory tract. While temporal trends in viral diversity are limited, spatial patterns are clear, with heterogeneity in the viral genotypes detected at distinct anatomical sites revealing extensive compartmentalization of reassortment and replication. Our data indicate that the dynamics of viral replication in mammals allow diversification through reassortment but that the spatial compartmentalization of variants likely shapes their evolution and onward transmission.

Long-term, low-dose prednisolone therapy in frequently relapsing nephrotic syndrome

The efficacy of daily administration of a small dose of prednisolone was examined in 21 patients with corticosteroid-responsive, frequently relapsing nephrotic syndrome (FRNS). After induction of remission of a third or subsequent relapse with a 6-week course of prednisolone (standard therapy with prednisolone, STP), this drug was continued in a single daily dose of 0.25 mg/kg body weight (low-dose prednisolone, LDP) for 18 months. Relapses occurring during this period were treated with STP, following which LDP therapy was resumed. The historical controls comprised 14 patients with FRNS in whom relapses were treated with STP and who were observed over a minimum period of 30 months. The two groups were comparable for age at the onset of nephrotic syndrome and sex. Twenty patients completed LDP therapy, during which 12 had no relapse, 6 had infrequent and 2 frequent relapses (1 patient became steroid dependent and was taken off LDP). Twelve patients were followed for 12-42 months after stoppage of LDP; during this period 7 had no relapse, 4 had infrequent relapses and 1 showed steroid dependence. The number of relapses during LDP therapy (0.5/patient per year) was significantly less (P less than 0.001) than in the preceding 12 months (3.62/patient per year), and continued to remain low during the following 12 months (0.6/patient per year). Whereas the frequency of relapses in the LDP group was similar to that in the historical control group in the 1st year of comparison, it was significantly less during LDP therapy (0.5/patient per year versus 2.25/patient per year). No side effects were observed in patients on the LDP regimen, at the end of which the height percentiles improved in 6 patients and remained unchanged in 14. Our observations indicate that long-term therapy with a small daily dose of prednisolone can significantly reduce the number of relapses in patients with FRNS, and that the beneficial effect may continue even after its stoppage.

Urinary excretion of minerals, oxalate, and uric acid in north Indian children

Urinary excretion of calcium, magnesium, phosphate, uric acid, oxalate, and creatinine was measured in 208 children (aged 8-15 years, 124 boys, 84 girls), living in a residential school near New Delhi. Levels were reduced compared with those reported from developed countries. The 95th percentile value of 24-h creatinine excretion was 33.4 mg/kg, calcium 2.2 mg/kg, magnesium 2.9 mg/kg, phosphate 9.4 mg/kg, uric acid 4.4 mg/kg, and oxalate 1.5 mg/kg. The 95th percentile value of the urine calcium/creatinine ratio was 0.15 and oxalate/creatinine 0.06. The dietary intake of proteins, calcium, and other nutrients in these children was less than recommended and explained the reduced urinary excretion observed. Physicians need to be aware of the regional patterns of normal urinary excretion of these constituents.

Calcineurin inhibitor induced nephrotoxicity in steroid resistant nephrotic syndrome

Prolonged therapy with calcineurin inhibitors (CNI) is effective in patients with difficult nephrotic syndrome. However, information on prevalence and risk factors for nephrotoxicity in children with steroid-resistant nephrotic syndrome is limited. This retrospective observational study was conducted on 40 patients with steroid-resistant nephrotic syndrome treated with cyclosporine (CyA) (n = 28) or tacrolimus (n = 12) for more than 2 years. Nephrotoxicity was defined by the presence of striped fibrosis involving ≥10% of the interstitium or nodular hyalinosis in more than one arteriole. Ten additional parameters were graded semi-quantitatively. Continuous data are presented as median and interquartile range (IQR). The median (IQR) age at onset of nephrotic syndrome and CNI therapy were 30 (21-45) and 49.5 (40-102.5) months. A second renal biopsy, following 30 (26-35) months of CNI therapy, showed histological toxicity in 10 (25%) patients. Toxicity was seen in 7 and 3 patients receiving CyA and tacrolimus, respectively, and 5 patients each with minimal change and focal segmental glomerulosclerosis. Therapy with CNI was associated with significant increases in scores for global glomerulosclerosis, tubular atrophy, interstitial fibrosis, nonnodular arteriolar hyalinosis (P < –0.001 for all), arteriolar smooth-muscle vacuolization (P = –0.02), juxtaglomerular hyperplasia (P = –0.002), and tubular microcalcinosis (P = –0.06). Risk factors for nephrotoxicity were initial resistance (OR 9; 95% CI 1.0-80.1; P = –0.049); dose of CyA (OR 9.2; 95% CI 1.1-74.6; P = –0.037); duration of heavy proteinuria (OR 1.2; 95% CI 1.0-1.4; P = –0.023); and hypertension during therapy (OR 6; 95% CI 1.3-28.3; P = –0.023). Following prolonged CNI therapy, one in four biopsies show features of toxicity. Prolonged duration of heavy proteinuria, hypertension, initial steroid resistance and high CyA dose predict the occurrence of nephrotoxicity.

Hypocalcemic heart failure masquerading as dilated cardiomyopathy

Hypocalcemia is a rare, but reversible, cause of congestive heart failure. We report a 4-month-old boy diagnosed as dilated cardiomyopathy who had prolonged QoTc with low blood levels of calcium, normal phosphate, elevated alkaline phosphatase and findings suggestive of rickets. In view of non response to calcium and vitamin D3, a possible diagnosis of VDDR I (Vitamin D-dependent rickets) was made and he was treated with calcium and calcitriol. The serum calcium levels normalised within 10 days, along with resolution of the signs and symptoms of heart failure, near normal left ventricular function and normalisation of QoTc. Pediatricians should be aware of the association of hypocalcemia with cardiac dysfunction and should keep it as a possible reversible cause of heart failure in children.

The profile and outcome of patients admitted to a pediatric intensive care unit

The records of all admissions to a 6-bed pediatric intensive care unit (PICU) over a period of 6 years were reviewed. The age, diagnosis, clinical service provided, duration of stay and outcome were recorded. Of the 3025 children admitted, 2092 (69.2%) were males. Neonates constituted 13.1% (400) and infants 57.1% (1727) of total admissions. The duration of stay ranged from 6 hours to 46 days, and 61 patients stayed for longer than 13 days (long-stay patients). The most common cause for admission was septicemia, seen in 459 patients (14.8%); 418 (13.8%) children had congenital heart disease, 407 (13.5%) lower respiratory tract infections (LRTI) and 261 (8.6%) meningitis. The most common conditions necessitating long-stay in the PICU were meningitis (20%), Landry-Guillain-Barre syndrome (16.6%), acute renal failure (20%), and septicemia (16.6%). There were 721 deaths giving a mortality of 23.5%. Of these 134 (18.6%) were due to septicemia, 103 (14.2%) due to congenital heart disease, 77 (10.6%) due to meningitis and 55 (7.6%) due to LRTI. The highest case fatality rate was seen with encephalitis (52.6%), followed by hepatic coma (51.3%), malignancies (43.2%), septicemia (29.1%) and meningitis (29.5%). The mortality was lower (9.8%) in long-stay patients than in short-stay patients (24.6%). There was gradual increase in proportion of cases requiring interventions including artificial ventilation (1% to 35%), peritoneal dialysis (1.5% to 11%), insertion of central venous pressure lines (0 to 10%), over the last 6 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Fluoride-associated ultrastructural changes and apoptosis in human renal tubule: a pilot study

The susceptibility of the kidneys to fluoride toxicity can largely be attributed to its anatomy and function. As the filtrate moves along the complex tubular structure of each nephron, it is concentrated in the proximal and distal tubules and collecting duct. It has been frequently observed that the children suffering from renal impairments also have some symptoms of dental and skeletal fluorosis. The findings suggest that fluoride somehow interferes with renal anatomy and physiology, which may lead to renal pathogenesis. The aim of this study was to evaluate the fluoride-associated nephrotoxicity. A total of 156 patients with childhood nephrotic syndrome were screened and it was observed that 32 of them had significantly high levels ( p ≤ 0.05) of fluoride in urine (4.01 ± 1.83 ppm) and serum (0.1 ± 0.013 ppm). On the basis of urinary fluoride concentration, patients were divided into two groups, namely group 1 (G-1) ( n = 32) containing normal urine fluoride (0.61 ± 0.17 ppm) and group 2 (G-2) ( n = 32) having high urine fluoride concentration (4.01 ± 1.83 ppm). Age-matched healthy subjects ( n = 33) having normal levels of urinary fluoride (0.56 ± 0.15 ppm) were included in the study as control (group 0 (G-0)). Kidney biopsies were taken from G-1 and G-2 only, who were subjected to ultrastructural (transmission electron microscopy) and apoptotic (terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling) analysis. Various subcellular ultrastructural changes including nuclear disintegration, chromosome condensation, cytoplasmic ground substance lysis, and endoplasmic reticulum blebbing were observed. Increased levels of apoptosis were observed in high fluoride group (G-2) compared to normal fluoride group (G-1). Various degrees of fluoride-associated damages to the architecture of tubular epithelia, such as cell swelling and lysis, cytoplasmic vacuolation, nuclear condensation, apoptosis, and necrosis, were observed.

Aetiology of nephrolithiasis in north Indian children

The aetiology of nephrolithiasis was investigated in 32 north Indian children (25 boys, 7 girls, mean age 7.9 +/- 3.3 years). An underlying disorder was detected in 16 (50%) patients and included idiopathic hypercalciuria (8 patients), hyperoxaluria (3 patients) and renal tubular acidosis, primary hyperparathyroidism and hyperuricosuria (1 patient each). Magnesium ammonium phosphate calculi were found in 2 patients with recurrent urinary tract infections, 1 of whom had a duplex pelvic collecting system. In 16 patients (50%) a cause for renal calculi was not identified. Our findings suggest that an underlying disorder is present in a large proportion of children with nephrolithiasis where appropriate treatment may be beneficial.

Phrenic nerve palsy: a rare complication of indwelling subclavian vein catheter

The use of central venous catheters as access for hemodialysis has become common in children with end-stage renal disease. Phrenic nerve palsy is an unusual complication of this procedure. We report a case of delayed right diaphragmatic palsy due to phrenic nerve damage resulting from an indwelling right subclavian catheter in a 3-year-old child.