Topical therapy and skin care for transplant-associated atopic dermatitis in children and adolescents.

BACKGROUND: New-onset allergic diseases, such as food allergy or atopic dermatitis, can develop after allogeneic transplantation. There are limited reports of new-onset atopic dermatitis after allogeneic hematopoietic stem cell transplantation in children and adolescents, and its treatment is yet to be established. The pathogenesis may differ from typical atopic dermatitis in terms of alloimmunity including graft-versus-host disease. METHODS: We present five children and adolescents with new-onset atopic dermatitis after allogeneic hematopoietic stem cell transplantation. The characteristics and clinical profiles of skin treatment after hematopoietic stem cell transplantation are summarized. RESULTS: Graft-versus-host disease prophylaxis included systemic tacrolimus for all patients. After hematopoietic stem cell transplantation, all patients achieved complete donor chimerism of the bone marrow and had acute graft-versus-host disease of the skin. After engraftment, all patients had skin lesions that met the international consensus diagnostic criteria for atopic dermatitis. None of the patients met the diagnostic criteria for chronic graft-versus-host disease. Topical therapy and skin care based on atopic dermatitis guidelines improved skin condition and atopic dermatitis severity scores in all patients. In addition, type 2 inflammatory markers improved accordingly. CONCLUSION: Topical therapy and skin care may be effective for transplant-related atopic dermatitis after hematopoietic stem cell transplantation. When extensive dermatitis is observed after hematopoietic stem cell transplantation, this treatment may avoid excessive immunosuppressive therapy if it meets the diagnostic criteria for atopic dermatitis.

Reduced-intensity conditioning is effective for allogeneic hematopoietic stem cell transplantation in infants with MECOM-associated syndrome.

Mutations in the MECOM encoding EVI1 are observed in infants who have radioulnar synostosis with amegakaryocytic thrombocytopenia. MECOM-associated syndrome was proposed based on clinical heterogeneity. Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative treatment for progressive bone marrow failure. However, data regarding allogeneic HSCT for this rare disease are limited. We retrospectively assessed overall survival, conditioning regimen, regimen-related toxicities and long-term sequelae in six patients treated with allogeneic HSCT. All patients received a reduced-intensity conditioning (RIC) regimen consisting of fludarabine, cyclophosphamide or melphalan, and rabbit anti-thymocyte globulin and/or low-dose total body/thoracic-abdominal/total lymphoid irradiation, followed by allogeneic bone marrow or cord blood transplantation from unrelated donors between 4 and 18 months of age. All patients survived and achieved stable engraftment and complete chimerization with the donor type. Moreover, no patient experienced severe regimen-related toxicities, and only lower grades of acute graft-versus-host disease were observed. Three patients treated with low-dose irradiation had relatively short stature compared to three patients not treated with irradiation. Therefore, allogeneic HSCT with RIC is an effective and feasible treatment for infants with MECOM-associated syndrome. Future studies are needed to evaluate the use of low-dose irradiation to avoid risks of other long-term sequelae.

Changes of cancer diagnosis disclosure to children in Japan in the last 20 years.

BACKGROUND: The practice of cancer diagnosis disclosure to children has been changed with the times. The regulations of clinical trials in the 2000s might change the practice in Japan. However, the perspective of this topic among children and adults has not been investigated in detail. METHODS: We studied changes in the practice of information sharing with children with cancer at pediatric cancer centers and the perspective of cancer diagnosis disclosure to children among school children, their parents and pediatric oncologists in the last 20 years by comparing the results of questionnaire surveys conducted in 1998, 2008 and 2018. RESULTS: This study revealed that the performing rate has increased with the times, but the institutions actively performing for children aged 7-9 years were 36.4% even in the 2018 survey. More than 70% of children wished diagnosis disclosure if they suffer from cancer in the series of surveys, while the ratio of parents who tell cancer diagnosis to their children hovered at 34.5 to 53.7% (p < 0.001 in all surveys). The ratio of pediatric oncologists having the policy to perform diagnosis disclosure proactively increased from 9.3 to 60.0%, while that of parents having the same policy stayed at 5.3% even in 2018. CONCLUSIONS: The performing rate of information sharing with children with cancer was significantly changed in the last 20 years. The opinion gaps were observed between parents and children and between parents and pediatric oncologists.

Clofarabine monotherapy in two patients with refractory Langerhans cell histiocytosis.

BACKGROUND: Better therapeutic options other than conventional chemotherapy for pediatric patients with refractory Langerhans cell histiocytosis (LCH) remain undetermined. CASE: We successfully treated two patients with refractory and risk organ negative LCH with clofarabine (CLO) monotherapy after recurrence. We administered total 23 courses of CLO monotherapy in patient 1 and 4 courses in patient 2. Both patients had distinct clinical manifestations but achieved a durable complete response with acceptable adverse effects of transient myelosuppression. CLO monotherapy was still effective when he had the second recurrent lesion after first completion of CLO in patient 1. We could discontinue prednisolone to control his refractory inflammation of LCH after completing CLO chemotherapy in patient 2. CONCLUSION: Although large-scale studies are warranted, CLO monotherapy could be a therapeutic option for high efficacy and feasibility besides other intensive combination chemotherapies or allogeneic hematopoietic stem cell transplantation for refractory LCH without risk organ involvement in children.

Pediatric psoriasis induced by HLA-B46-Cw1 haplotype: A retrospective study of psoriasis onset after hematopoietic stem cell transplantation.

Genome-wide association studies have identified more than 60 susceptibility loci for psoriasis, highlighting the role of genetics in psoriasis development. Although the HLA region is suggested as the most prominent susceptibility locus, the role of the HLA haplotype in the development of psoriasis is unclear. The aim of this study is to investigate how HLA haplotype changes affect the onset of psoriasis and which HLA haplotypes are associated with the development of psoriasis. A longitudinal, retrospective case series study of children was conducted at Tohoku University Hospital in Japan, between November 1981 and October 2020. We evaluated a total of 378 pediatric patients who underwent hematopoietic stem cell transplantation in the Department of Pediatrics. The background of these patients and their HLA haplotypes before and after transplantation was assessed. Among the 378 cases, aged 0-22 years old (median age 6) identified, 117 cases received autologous transplantation, 260 cases received allogeneic transplantation, and one case received syngeneic transplantation. Only two cases developed de novo psoriasis, and these cases had acquired HLA-B46-Cw1 after allogeneic transplantation. Others who had HLA-B46-Cw1 before and after allogeneic transplantation did not develop psoriasis. Our findings suggest that the HLA-B46 and HLA-Cw1 combination contributes to the development of psoriasis in this Asian population.

Ruxolitinib treatment of a patient with steroid-dependent severe autoimmunity due to STAT1 gain-of-function mutation.

Signal transducer and activator of transcription 1 gain-of-function (STAT1 GOF) mutations are the most common cause of chronic mucocutaneous candidiasis (CMC). We report the effect of oral ruxolitinib, an inhibitor of Janus kinase (JAK) family tyrosine kinases, on the clinical and immune status of a 3-year-old male with steroid-dependent severe autoimmunity due to a STAT1 GOF T385M mutation. The patient's susceptibility to infection improved with antimicrobial prophylaxis and immunoglobulin replacement therapy, but he continued to exhibit severely disabling symptoms of autoimmunity. More than one-third of patients with STAT1 GOF mutations present with autoimmune manifestations, and this patient's mutation was reported to cause CMC with autoimmunity. We analyzed the interleukin (IL)-17A and IFN-γ levels and immunophenotype by flow cytometry before and during treatment with ruxolitinib. The peripheral IL-17A level did not increase, but the IFN-γ level decreased after 4 months of therapy. The STAT1 phosphorylation level decreased significantly upon stimulation of patient cells with IFN-γ. Clinically, cytomegalovirus reactivation occurred, but was controlled. No other adverse effect was noted. We report the potential of JAK1/2 inhibition with ruxolitinib for both CMC and steroid-dependent autoimmunity. However, long-term administration is necessary, as the effect is not sustained after treatment is discontinued.

Secondary bone/soft tissue sarcoma in childhood cancer survivors: a nationwide hospital-based case-series study in Japan.

BACKGROUND: Secondary cancer is the most life-threatening late effect of childhood cancer. We investigated the clinical features of secondary bone/soft tissue sarcoma among childhood cancer survivors (CCSs). METHODS: We conducted a retrospective case-series study of 10 069 CCSs newly diagnosed with cancer between 1980 and 2009 across 15 Japanese hospitals. Twenty-one cases of pathologically diagnosed secondary bone/soft tissue sarcoma were selected, and the respective clinical courses were determined using additional questionnaires. RESULTS: The primary cancers included retinoblastoma (n = 7), acute lymphoblastic leukemia (n = 5), lymphoma (n = 5), osteosarcoma (n = 1), rhabdomyosarcoma (n = 1), brain tumor (n = 1) and Langerhans cell histiocytosis (n = 1). The median age at the primary cancer diagnosis was 2.9 years, and the male-to-female ratio was 16:5. The histological classifications of the secondary sarcoma included osteosarcoma (n = 10), malignant peripheral nerve sheath tumor (n = 4), rhabdomyosarcoma (n = 3), Ewing's sarcoma (n = 3) and primitive neuroectodermal tumor (n = 1). The median latency period to the secondary sarcoma was 10.2 years. Significant risk factors for secondary sarcoma in the multivariate Cox regression model included a history of retinoblastoma as the primary cancer (hazard ratio [HR], 20.9; 95% confidence interval [CI], 5.70-76.5) and autologous stem cell transplantation (SCT) (HR, 2.56; 95% CI, 1.08-6.03). Seventeen CCSs with secondary sarcoma underwent radiation, and nine, hematopoietic SCT. Twelve CCSs with secondary sarcoma achieved disease-free survival, while CCSs with hematological cancer or relapsed primary cancer who developed secondary sarcoma had the worst prognoses. CONCLUSION: The prognoses of CCSs with secondary sarcoma may depend on the primary cancer or prior relapse of primary cancer.

Secondary cancer after a childhood cancer diagnosis: viewpoints considering primary cancer.

BACKGROUNDS: Multidisciplinary therapy has increased the risk of subsequent late effects, but detailed analyses on secondary cancers in childhood cancer survivors (CCSs) are limited in Asian countries. METHODS: This was a retrospective cohort study comprising 10,069 CCSs who were diagnosed between 1980 and 2009 across 15 Japanese hospitals. We conducted secondary analyses to estimate the incidence of secondary cancer according to each primary malignancy and to elucidate the association between primary and secondary cancers. We also explored the risk factors for the development of secondary cancer in each independent primary malignancy. RESULTS: The cumulative incidence of secondary cancer at 20 years varied among primary cancers: hematological malignancy, 3.1% (95% CI 2.2-4.3); retinoblastoma, 6.6% (95% CI 1.5-16.8); pediatric solid tumor, 2.5% (95% CI 1.3-4.2); brain tumors, 5.2% (95% CI 1.7-11.8) bone/soft tissue sarcoma, 5.2% (95% CI 2.3-10.1); and others, 3.3% (95% CI 1.6-6.0) (p = 0.015). The cumulative incidence of secondary cancers is highest in those with osteosarcoma (13.1%) followed by those with hepatoblastoma (8.4%) and retinoblastoma (6.6%). Close association between the primary and secondary cancer diagnoses was found. The risk factors for secondary cancer development depended on the primary cancer, but autologous/allogeneic stem cell transplantation was a relatively common risk factor. CONCLUSION: The cumulative incidence of secondary cancer varied among primary cancers. The primary cancer was closely associated with the secondary cancer but stem cell transplantation was a common risk factor for secondary cancers among CCSs.

Infantile hemangiopericytoma of the tongue-Efficacy of ex utero intrapartum treatment procedure and combined-modality therapy.

Here we present an extremely rare case of giant infantile hemangiopericytoma (HPC) of the tongue diagnosed prenatally by fetal ultrasonography and MR imaging. Due to airway stenosis, the patient was delivered by the ex utero intrapartum treatment (EXIT) procedure at 36 weeks of pregnancy. Initial diagnosis was infantile hemangioma based on physical examination, diagnostic imaging and the high incidence of hemangioma. The tumor was resistant to conservative treatments. Due to severe tumor hemorrhage, the nutrient vessel was embolized by endovascular treatment on the 73th day after birth. Two days after embolization, a hemiglossectomy was performed. Histological analysis after surgery diagnosed infantile HPC with microscopically positive stumps. After receiving adjuvant chemotherapy, the patient has had no recurrence after 53 months with normal speech and swallowing function resulting in normal growth. Our findings support that infantile HPC is one of the differential diagnosis of infantile hemangioma. The EXIT procedure could be effective for infants with upper respiratory stenosis by head and neck tumor diagnosed prenatally. Though complete resection is required for infantile HPC, our report suggests that a conservative surgical approach followed by adjuvant chemotherapy should be used for giant head and neck infantile HPC.

Health-related quality of life in Japanese children with acute lymphoblastic leukemia during and after chemotherapy.

BACKGROUND: Quality of life (QOL) as a treatment outcome has not yet been evaluated among patients receiving a specific treatment regimen by treatment phase in a consistent manner. This exploratory cross-sectional study evaluated the QOL of children with acute lymphoblastic leukemia (ALL) receiving one of the most popular treatment regimens in Japan (Japan Association of Childhood Leukemia Study ALL-02 revised protocol). METHODS: Children aged 5-18 years with newly diagnosed B-cell precursor ALL were included. The Pediatric Quality of Life Inventory™ 4.0 Generic Core Scales (PedsQL-J) were completed by children with ALL and their siblings, as well as by age- and sex-matched healthy controls. PedsQL Cancer Module (PedsQL-C) scores were also collected from children with ALL. RESULTS: QOL in children with ALL of the consolidation phase group was significantly decreased compared with that of healthy controls, except in the area of emotional functioning. Regarding the maintenance phase group, QOL impairment was noted in the physical and school functioning, but no differences were noted in social functioning. The off-treatment group had a large effect size only for physical functioning, and the social functioning score was even better in children with ALL than in matched controls. QOL of children with ALL differed with treatment phase. Effect size varied with function and treatment phase. CONCLUSIONS: QOL may change with the progression of treatment, and the timing of these changes varied according to function and problem.

Somatic BRAF c.1799T>A p.V600E Mosaicism syndrome characterized by a linear syringocystadenoma papilliferum, anaplastic astrocytoma, and ocular abnormalities.

Genetic mosaicism for somatic mutations of oncogenes is common in genodermatoses, which can be complicated with extra-cutaneous abnormalities. Here we describe an infant with a congenital anaplastic astrocytoma, a linear syringocystadenoma papilliferum, and ocular abnormalities. The BRAF c.1799T>A p.V600E mutation was detected in both the brain and skin tumor cells but not in the blood or normal skin cells, suggesting somatic mosaicsism for the mutation. Clinically, the brain tumor gradually became life threatening without any response to conventional chemotherapies including carboplatin, etoposide, and temozolomide. Vemurafenib, a BRAF p.V600E inhibitor, was administered daily after the detection of the BRAF mutation. This single-agent therapy was dramatically effective against the anaplastic astrocytoma; the tumor regressed, the cerebrospinal fluid cell count and protein levels decreased to normal levels, and hydrocephalus resolved. Moreover, other lesions including a corneal cyst also responded to vemurafenib. The brain tumor continued shrinking after 6 months of treatment. We present a genodermatosis syndrome associated with BRAF c.1799T>A p.V600E mosaicism. This syndrome may represent a new entity in the mosaic RASopathies, partly overlapping with Schimmelpenning-Feuerstein-Mims syndrome, which is driven by mosaicism of HRAS and/or KRAS activating mutations. Screening for BRAF c.1799T>A p.V600E is especially useful for those with malignant tumors, because it is one of the most-druggable targets.

Secondary cancers after a childhood cancer diagnosis: a nationwide hospital-based retrospective cohort study in Japan.

BACKGROUND: The epidemiology of secondary cancers in childhood cancer survivors has been unknown in Asian countries. Our aim is to assess the incidence and risk factors for secondary cancers through a nationwide survey in Japan. METHODS: A retrospective cohort study comprising 10,069 children who were diagnosed with cancer between 1980 and 2009 was conducted in 15 Japanese hospitals. The cumulative incidence rate was calculated using death as the competing risk and compared by the Gray method. The standardized incidence ratio (SIR) was defined as the ratio of the number of observed cancers divided by the number of expected cancers. The risk factors were analyzed using Cox regression analysis. RESULTS: One hundred and twenty-eight patients (1.3 %) developed secondary cancers within a median follow-up of 8.4 years. The cumulative incidence rate was 1.1 % (95 % confidence interval [CI] 0.9-1.4) at 10 years and 2.6 % (95 % CI 2.1-3.3) at 20 years after primary cancer diagnosis. Sensitivity analysis, limited to 5-year survivors (n = 5,387), confirmed these low incidence rates. The SIR of secondary cancers was 12.1 (95 % CI 10.1-14.4). In the Cox analysis, the hazard ratios for secondary cancers were 3.81 (95 % CI 1.53-9.47) for retinoblastoma, 2.78 (95 % CI 1.44-5.38) for bone/soft tissue sarcomas, and 1.81 (95 % CI 1.16-2.83) for allogeneic stem cell transplantation. CONCLUSIONS: The cumulative incidence of secondary cancers in children in Japan was not high; however, the SIR was relatively high. Retinoblastoma or sarcoma in addition to allogeneic stem cell transplantation were significant risk factors for secondary cancers.

Mesenchymal chondrosarcoma diagnosed on FISH for HEY1-NCOA2 fusion gene.

Mesenchymal chondrosarcoma (MC) is an extremely rare subtype of chondrosarcoma that has a small round-cell sarcoma with focal cartilaginous differentiation, often with a pericytomatous vascular pattern. The non-cartilaginous components are usually dominant, and such lesions might be confused with other small round-cell tumors. Recently, a tumor-specific HEY1-NCOA2 fusion gene was identified in MC. Here we report the case of a 9-year-old boy who was diagnosed with MC by detection of HEY1-NCOA2 fusion signals in almost 50% of tumor cells in tissue sections on fluorescence in situ hybridization (FISH). In this way, the tumor was definitively diagnosed as MC. This case suggests that the detection of the HEY1-NCOA2 fusion gene on FISH is of diagnostic value for MC.

GNE myopathy associated with congenital thrombocytopenia: a report of two siblings.

GNE myopathy is an autosomal recessive muscular disorder caused by mutations in the gene encoding the key enzyme in sialic acid biosynthesis, UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE/MNK). Here, we report two siblings with myopathy with rimmed vacuoles and congenital thrombocytopenia who harbored two compound heterozygous GNE mutations, p.V603L and p.G739S. Thrombocytopenia, which is characterized by shortened platelet lifetime rather than ineffective thrombopoiesis, has been observed since infancy. We performed exome sequencing and array CGH to identify the underlying genetic etiology of thrombocytopenia. No pathogenic variants were detected among the known causative genes of recessively inherited thrombocytopenia; yet, candidate variants in two genes that followed an autosomal recessive mode of inheritance, including previously identified GNE mutations, were detected. Alternatively, it is possible that the decreased activity of GNE/MNK itself, which would lead to decreased sialic content in platelets, is associated with thrombocytopenia in these patients. Further investigations are required to clarify the association between GNE myopathy and the pathogenesis of thrombocytopenia.

Development of the Japanese version of the Minneapolis-Manchester Quality of Life Survey of Health - Adolescent Form (MMQL-AF) and investigation of its reliability and validity.

BACKGROUND: There are very few reliable and valid measures in Japan assessing health-related quality of life (HRQOL) in children with cancer. The present study aimed to develop a Japanese version of the Minneapolis-Manchester Quality of Life Survey of Health Adolescent Form (MMQL-AF), which is a measure for assessing the HRQOL of childhood cancer survivors, and investigate its reliability and validity. METHODS: Participants were 141 children with cancer who had been off therapy for more than one year and 183 healthy controls. The reliability and internal consistency of the measure were assessed through test-retest methods using Cronbach's coefficient alpha and intra-class correlation coefficients (ICCs). For validation of the measure, factorial validity, concurrent validity using the Japanese version of PedsQL 4.0 Generic Core Scales (PedsQL-J), and discriminant validity using comparisons between children with cancer and healthy controls were investigated. RESULTS: Of the 46 items in the original version, 44 items were determined to comprise the Japanese version of the MMQL-AF. Cronbach's coefficient alphas for each subscale were high ranging from 0.83 to 0.89. Test-retest reliability ranged between ICC 0.79 to 0.96. Investigation of concurrent validity using the PedsQL-J demonstrated strong correlations in physical functions and moderate correlations for other factors. A significant difference was observed between children with cancer and healthy controls. CONCLUSIONS: Thus, the Japanese version of the MMQL-AF served as a self-evaluation questionnaire that allowed for practical, comprehensive, and multidimensional measurement of HRQOL specific to childhood cancer survivors.

A case series of CAEBV of children and young adults treated with reduced-intensity conditioning and allogeneic bone marrow transplantation: a single-center study.

BACKGROUND: Epstein-Barr virus (EBV)-infected T or NK cells cause chronic active EBV infection (CAEBV). Allogeneic hematopoietic stem cell transplantation (HSCT) is curative treatment for CAEBV patients. However, chemotherapy prior to HSCT and optimal conditioning regimen for allogeneic HSCT are still controversial. PATIENTS AND METHODS: We retrospectively analyzed five patients with CAEBV treated with reduced-intensity conditioning (RIC) consisted of fludarabine, cyclophosphamide, and low-dose total-body irradiation followed by allogeneic bone marrow transplantation in a single institute. Only one of five patients received chemotherapy prior to transplantation. We analyzed EBV-infected cells in a patient whose EBV load increased after HSCT by T-cell repertoire assay, separation of T-cell subpopulations, in situ hybridization and microsatellite analysis. RESULTS: All five patients achieved engraftment, complete chimera, and eradication of EBV load. All patients have been alive without any serious regimen-related toxicity for more than 16 months following HSCT. However, one patient transplanted from HLA-matched sibling donor developed clonal proliferation of CD4+ Vß3+ T cells caused by monoclonal EBV infection on day 99 after transplantation. Further analysis revealed that the CD4+ Vß3+ T cells selectively harbored EBV genome, and these infected cells were derived from donor T cells. CONCLUSIONS: Allogeneic HSCT with RIC is a safe and effective treatment for better overall survival and less regimen-related toxicity in patients with CAEBV. Our first pediatric case reported in the literature suggests that we should consider the possibility of persistent EBV infection in donor T cells as well as the relapse in recipient cells if EBV load increases after allogeneic HSCT.

Successful treatment with rituximab of an infant with refractory autoimmune hemolytic anemia.

Autoimmune hemolytic anemia (AIHA) is a rare disease in infants, for which steroids are recognized as a first-line therapy for patients. Rituximab, a humanized monoclonal antibody raised against CD20, has been used in the treatment of autoimmune diseases, including AIHA, in adults and children. Due to limited follow-up study of the use of rituximab in the treatment for AIHA, its long-term efficacy, adverse effects, and immunological reconstitution of B cells have not been fully evaluated in infants. Here, we report a 3-month-old female patient with refractory AIHA, who was successfully treated with rituximab. Hemolytic anemia improved rapidly, and there were no severe adverse effects caused by rituximab. After 4.5 months following rituximab treatment, peripheral B cells were gradually reconstituted and required no intravenous immunoglobulin replacement thereafter. The patient has remained disease-free for more than 30 months without any additional treatment. This case suggests that rituximab may be a valuable therapeutic option, given its efficacy and minimal adverse effects in infants with therapy-resistant AIHA.

Interstitial lung disease in two brothers with novel compound heterozygous ABCA3 mutations.

Mutations in genes critical for surfactant metabolism, including surfactant protein C (SP-C) and ABCA3, are well-recognized causes of interstitial lung disease. Recessive mutations in ABCA3 were first attributed to fatal respiratory failure in full-term neonates, but they are also increasingly being recognized as a cause of respiratory disorders with less severe phenotypes in older children and also adults. Here, we report a 20-month-old boy with interstitial lung disease caused by two distinct ABCA3 mutations. Initial treatment with methylprednisolone was unsuccessful, but the additional administration of hydroxychloroquine was effective. The family history revealed that the patient's older brother had died of idiopathic interstitial lung disease at 6 months of age, suggesting a genetic etiology of the disease. Sequence analyses of SP-C and ABCA3 genes were performed using DNA samples from the patient himself, his parents, and his brother. These analyses revealed novel compound heterozygous mutations in the coding exons of ABCA3 in both the patient and his brother: c.2741A > G, of paternal origin, and c.3715_3716insGGGGGG, of maternal origin. Conclusion Since ABCA3 mutations seem to be a heterogeneous entity with various phenotypes, we recommend genetic testing for mutations in SP-C and ABCA3 genes to be considered in children with unexplained interstitial lung disease.