Copyright ©ERS Journals Ltd 2008 Childhood sarcoidosis: long-term follow-up1 The Heart Centre, Division of Lung Transplantation, Rigshospitalet, University of Copenhagen, Copenhagen, and 2 Dept of Paediatrics, Næstved Hospital, Næstved, Denmark. CORRESPONDENCE: N. Milman, Lindevangen 87B, DK-2830 Virum, Denmark, Fax: 45 35452648. E-mail: nils.mil{at}dadlnet.dk Keywords: Children, follow-up, granulomatosis, sarcoidosis
Received: January 31, 2007
The aim of the present study was to describe clinical features and long-term survival in childhood sarcoidosis. In total, 46 ethnic Caucasian Danish children (aged <16 yrs, 24 males) with sarcoidosis were identified in 1979–1994. In 33 (72%) children, diagnosis was verified by histology and, in the remaining 13, by clinical and radiological findings. In total, 37 subjects had a follow-up examination. Median (range) age at onset of disease was 14 (0.7–15.8) yrs and median (range) clinical follow-up was 15 (3–23) yrs after onset of disease. The median (range) age at clinical follow-up was 28 (17–30) yrs. At follow-up: 36 (78%) children recovered completely; 30 (65%) showed complete clinical regression at a median (range) 0.7 (0.6–5.9) yrs after onset of disease; two (4%) recovered with organ damage (unilateral loss of vision, abnormal chest radiograph); five (11%) still had chronic active disease with multiorgan involvement and impaired lung function; and three (7%) were deceased, due to central nervous system sarcoidosis and acute myeloid leukaemia probably caused by cytostatics. In Danish children, sarcoidosis had a favourable prognosis; the majority recovered <6 yrs after onset of disease. Some developed chronic active disease and impairment of pulmonary function, demanding continuous medical treatment. Prognosis was not related to the age at onset of disease. Erythema nodosum was associated with a good prognosis, and central nervous system involvement with a poor prognosis. Sarcoidosis is a disease of unknown aetiology, characterised by the formation of non-necrotising epithelioid cell granulomas with multiorgan involvement 1. The overall incidence of sarcoidosis in Denmark is 7.2/100,000 person-yrs, with the peak incidence occurring at 30 yrs of age 2. Among Danish children, the incidence rises from 0.06/100,000 person-yrs at age 4 yrs to 1.02/100,000 person-yrs at age 14–15 yrs with an overall incidence of 0.29/100,000 person-yrs 2, 3. The incidence declines from the Western to the Eastern part of Denmark both in adults 2 and in children 3. The regional variations in incidence rates are probably due to regional differences in diagnostic awareness, although environmental and genetic differences might also be involved 2. The natural history of sarcoidosis has been studied most extensively in adults 2, 4–6. In contrast, the natural history and prognosis of sarcoidosis has been scarcely investigated in children 3. Consequently, the objective of the present study was to describe the long-term course and prognosis of childhood sarcoidosis in Denmark, especially with respect to clinical outcome and vital prognosis.
The study was approved by the ethics committee in the region of Copenhagen. In Denmark, patients discharged from any hospital are registered according to their diagnoses in a Nationwide Patient Registry, established in 1979 and hosted by the National Board of Health. Patients with a diagnosis of sarcoidosis in the period 1979–1994 were drawn from this National Patient Registry 3. In total, 5,536 patients were drawn from the Registry; 81 patients were aged <16 yrs. By reassessment of the patient records and registry information, the diagnosis of sarcoidosis could be reconfirmed in 49 (61%) patients, i.e. in one more patient than in the initial series 3. From the present series of 49 patients, three patients were excluded: a pair of monozygotic twins, who later proved to have Blau syndrome 7 and an ethnic Lebanese young male who had returned to his country and was unavailable for follow-up. The final series thus comprised 24 males and 22 females (male/female ratio 1:1), all ethnic Caucasian Danes. In 33 (72%) patients, the diagnosis was verified by examination of tissue biopsy specimens showing sarcoid granulomas. In 13 patients, characteristic chest radiograph findings (hilar adenopathy) associated with typical clinical features and/or laboratory findings (erythema nodosum (EN), uveitis, peripheral lymphadenopathy and elevated serum angiotensin-converting enzyme (SACE)) substantiated the diagnosis 3. The subjects were invited by letter to a clinical follow-up examination in November, 1999. In total, 37 subjects responded and had a clinical examination, which is herein referred to as "clinical follow-up". At closure of the study in September, 2006, vital status on all 46 subjects was checked in the National Census Registry, which is herein referred to as "Registry follow-up". Clinical follow-up comprised a history, clinical examination, blood samples for biochemical analyses performed by standard laboratory methods and chest radiograph. Chest radiograph findings were scored in a blinded fashion by the present authors. Blood pressure was measured with a mercury manometer. Pulmonary function tests, including diffusing capacity of the lung for carbon monoxide (DL,CO), were performed using a body plethysmograph (Medical Graphics, St Paul, MN, USA).
Duration of follow-up Table 1
Two (4%) patients reported sarcoidosis in the family, one mother and one father, who both had recovered from the disease.
Clinical features at onset of disease
Treatment The children were followed and treated in the regional departments of paediatrics all over Denmark. There were no approved common guidelines for treatment, which was at the discretion of the local doctors, and it is beyond the scope of the present study to analyse the effect of therapy. Treatment was preferably given to patients with clinically overt pulmonary involvement, with extrathoracic organ involvement (e.g. CNS involvement) and with hypercalcaemia; 23 (51%) out of 45 (data were not available for one patient) of the children were treated with prednisolone for median (range) 1.3 (0.3–23) yrs. Two children were additionally treated with methotrexate (patient 1) or azathioprine (patient 2).
Outcome at follow-up
Five patients had chronic active sarcoidosis as follows. 1) A 4.3-yr-old (at onset) female (patient 3) had permanent impairment of lung function and active sarcoid colitis/proctitis at follow-up 18 yrs later. 2) A 0.7-yr-old (at onset) male (patient 1) had chronic active pulmonary sarcoidosis with impaired lung function at follow-up 24 yrs later. 3) A 15.3-yr-old (at onset) male (patient 4) with pulmonary sarcoidosis stage II and neurosarcoidosis, with impaired visual field, hypophyseal insufficiency and diabetes insipidus, was still on treatment at follow-up 21 yrs later. 4) A 14.5-yr-old (at onset) female (patient 5) with iridocyclitis, stage I pulmonary sarcoidosis and neurosarcoidosis with diabetes insipidus still had active stage I pulmonary sarcoidosis with normal lung function tests and diabetes insipidus at follow-up 10 yrs later. 5) A 13.3-yr-old (at onset) female (patient 6) with hypercalcaemia, nephrocalcinosis and stage I pulmonary sarcoidosis still had active stage III pulmonary sarcoidosis with impaired lung function at follow-up 23 yrs later.
Anthropometrics
Mean body mass index (BMI) was 24.3 kg·m–2. One (3%) female patient was underweight (BMI <18.5 kg·m–2); six (19%), two males and four females were moderately overweight (BMI 25.0–29.9 kg·m–2), and three (10%), two males and one female were obese (BMI
Organ involvement and course of disease
Three children had sarcoid skin lesions and one male (patient 1) with onset of sarcoidosis at 0.7 yrs of age still had chronic active pulmonary disease. In total, 13 children presented with uveitis/iridocyclitis. One had permanent unilateral loss of vision, but no activity in ocular disease at follow-up and one still had chronic active sarcoidosis, but no activity in ocular disease at follow-up.
The majority of children presented with mediastinal/hilar lymphadenopathy: 11 children presented with peripheral lymphadenopathy, predominantly on the neck. Of these, nine children recovered, one had sequela with unilateral loss of vision (table 4 Of the two patients presenting with abdominal pain, a 15.6-yr-old male had had a laparotomy. Mesenteric lymph nodes were enlarged and examination of appendix vermiformis showed noncaseating epithelioid cell granulomas 3. This patient recovered completely. The second patient, a 4.3-yr-old female, had sarcoid involvement of colon and rectum and at follow-up she still had chronic active sarcoidosis involving the colon and lungs (stage IV). Two children had peripheral facial palsy and iridocyclitis, of which, one recovered completely, and the other died of acute myeloid leukaemia. Three children aged 11.2–15.3 yrs at onset of disease had CNS involvement and one, in addition, had facial palsy. At follow-up, one patient still had chronic active sarcoidosis and two were deceased. None of the patients presented with clinically significant sarcoid-associated arthritis.
Laboratory analyses at follow-up
Serum soluble interleukin-2 receptor (S-sIL-2R) was measured in 28 subjects, in 24 who had recovered and in four with chronic active disease. All subjects who had recovered had normal S-sIL-2R levels, whereas all four subjects with active disease had elevated levels (table 5 Arterial blood pressure was normal, with a median of 119/80 mmHg in 29 out of 30 subjects. One male was diagnosed with arterial hypertension (160/123 mmHg) at follow-up.
Chest radiology
Changes in chest radiograph findings are shown in figure 1
Lung function Table 7
Sarcoidosis in the young child In one male (patient 1) the disease started at 8 months of age with fever and facial erythema. A skin biopsy was interpreted as panniculitis and vasculitis, but later revision disclosed granulomas. A repeat skin biopsy at 16 months of age showed epithelioid cell granulomas. Subsequently, the child developed iridocyclitis, splenomegaly, hypercalcaemia and elevated SACE. Chest radiograph showed hilar lymphadenopathy (stage I). The patient had been on life-long treatment with prednisolone. At one point, he was treated with methotrexate, which was discontinued due to hypo- -globulinaemia. At 25 yrs of age, the patient still presented with chronic active pulmonary sarcoidosis, chest radiograph stage I and pulmonary function tests showing normal spirometry values but decreased DL,CO 44% of predicted value and elevated S-sIL-2R. DNA sequencing showed no Blau syndrome-associated mutations in the exon 4 of the NOD2 (CARD15) gene.
Malignancy
Mortality
The incidence, clinical picture and prognosis of sarcoidosis display marked racial differences and the majority of studies on children have presented patient series containing subjects of different ethnic origins 8, 9, 10–14. The present study describes the initial clinical presentation and outcome of sarcoidosis in a racially uniform consecutive series of Danish children. The four most frequent initial presenting symptoms were EN in 22%, iridocyclitis in 22%, peripheral lymphadenopathy in 15% and cutaneous sarcoidosis in 7% of the patients. Arthritis was not a prominent feature in the series, even in children with EN. This observation is in contrast to previous series of childhood sarcoidosis, which emphasised that arthritis is a common symptom in small children with the disease 15, 16. However, those patients were racially heterogenous and were not examined for mutations of the NOD2 gene. The present authors original series 3 comprised a pair of monozygotic twins having early onset disease with arthritis/periarthritis. They were subsequently diagnosed by genetic analysis as having Blau syndrome 7. It is possible that many children previously classified as "early onset sarcoidosis" may in fact have Blau syndrome if properly investigated for NOD2 mutations. In the present series, one child had early onset sarcoidosis at 8 months of age. He developed skin sarcoidosis, iridocyclitis and had intrathoracic involvement, but no joint symptoms and no Blau associated mutations. He was extensively investigated for autoimmune disease/vasculitis with negative results. The present authors concluded that the patient had "true" early onset sarcoidosis, which appears to be extremely rare in children aged <1 yr.
In general, the prognosis of childhood sarcoidosis in the present group of patients was quite good. In total, 80% of the subjects recovered completely without functional impairment. However, EN appeared to be an important prognostic marker. Children presenting with EN had a favourable prognosis compared with children without EN. Similarly, children with scar sarcoidosis and peripheral lymphadenopathy had a good prognosis. Hypercalcaemia, iridocyclitis and CNS involvement were associated with a less favourable prognosis. The majority of subjects had anthropometrics that corresponded to the normal population. Three subjects had a height below the 5th percentile for age. Of these, one had not been treated with steroids and had recovered completely from sarcoidosis, whereas two had been on steroids for years due to chronic active disease. In the entire group of patients, one female was slightly underweight, had a complete recovery from sarcoidosis and was otherwise fit and healthy. In contrast, overweight was a common finding: 19% were moderately overweight and 10% were obese. These figures are comparable to the general population. Newly discovered arterial hypertension was found in one male at the follow-up examination. He had a normal BMI of 21 kg·m–2 and had smoked for 15 pack-yrs. Hypercalcaemia was found in 28% of the children at onset of disease, four of which had symptomatic hypercalcaemia 17. In another study 8, hypercalcaemia and hypercalciuria have been reported in 5–35% of the children. Hypercalciuria may occur even in the presence of normocalcaemia and may contribute to nephrolithiasis and nephrocalcinosis 16, 18. Four of the children in the present study had temporarily impaired renal function due to hypercalcaemia and one had nephrocalcinosis at the initial presentation. Renal dysfunction is most often due to hypercalcaemia, but may occasionally be elicited by granulomatous interstitial nephritis 16. In general, laboratory values at follow-up were within the normal reference intervals. Three subjects had slightly elevated plasma (P-) total calcium at follow-up, but only one of these had elevated P-ionised calcium as well. The disease activity marker SACE was elevated in one female with chronic active sarcoidosis. S-sIL-2R levels were normal in subjects who had recovered, while patients with chronic active disease had elevated levels. Consequently, the present authors assume that S-sIL-2R is a clinically useful marker of sarcoid disease activity 19.
Involvement of the peripheral nervous system and CNS is infrequent in adult Danish sarcoidosis patients affecting As in adults 5, the most common finding in childhood sarcoidosis is an abnormal chest radiograph 8, 12, 13. In the present series, >90% had abnormal chest radiograph at onset of disease, stage I in two thirds and stages II–III in one third of the subjects. At follow-up: 80% had a normal chest radiograph, although some of these subjects had slight mediastinal scarring, some with calcification of the mediastinal lymph nodes; 10% had chronic persistent stage I; and 10% had stages II–IV. This implies that 21% of the subjects presented with an abnormal chest radiograph several years after onset of the disease. However, only 9% of the subjects had impaired pulmonary function tests at follow-up. More than half of the children had been treated with prednisolone, which may have influenced (i.e. accelerated) the recovery. In a previous study on childhood sarcoidosis 14, 81% of the 21 children were treated with prednisolone. However, their group of patients contained 12 children of black ethnicity, in whom the disease takes a more severe course 1. Therefore, the two studies are not comparable. The present authors conclude that the most frequent initial symptoms/clinical findings in sarcoidosis of Danish children include iridocyclitis, peripheral lymphadenopathy and cutaneous sarcoidosis. In general, childhood sarcoidosis has a favourable prognosis, which is similar to the prognosis in adults. Prognosis appears not to be related to the age at onset of disease. The majority of children recover completely within 6 yrs after onset of disease, but a few recover with persisting organ damage. Some develop chronic active disease and impairment of pulmonary function demanding continuous medical treatment. Approximately 7% die at a young age due to sarcoidosis-related complications. In general, the presence of erythema nodosum is associated with a good prognosis, and central nervous system sarcoidosis is associated with a poor prognosis.
This work was supported by Dronning Louises Børnehospitals Forskningsfond.
None declared.
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