HLA-DQB1 0602 allele is associated with splenomegaly in Japanese sarcoidosis

Genetics of neurosarcoidosis

Sarcoidosis is a systemic, inflammatory, granulomatous disease characterized by great variability in organ involvement, clinical course, and severity. While pulmonary manifestations are almost universal, the central and peripheral nervous systems can also be affected. Neurosarcoidosis occurs in ∼5-15% of cases and is among the manifestations with the highest morbidity and mortality. It is known that sarcoidosis has genetic underpinnings and while multiple studies aimed at identifying associations to sarcoidosis susceptibility and prognosis, very few studies have focused on neurosarcoidosis. This review summarizes the genetic studies to date, compares and contrasts those findings with other genetic effects in sarcoidosis, and offers ideas for moving the field forward.

Multisystemic Sarcoidosis Presenting With Leg Ulcers, Pancytopenia, and Polyserositis Was Successfully Treated With Glucocorticoids: A Case Report and Literature Review

Introduction

Sarcoidosis is a chronic granulomatous disease of unknown etiology. A variety of studies have pointed out that almost every part of the body can be affected, but it most often affected the lungs and intrathoracic lymph nodes. However, cases of sarcoidosis involving multiple organs in one patient are rarely reported. We describe a unique case of sarcoidosis, which was characterized by multiorgan involvement, including leg ulcers, splenomegaly, pancytopenia, and polyserositis. Glucocorticoids were effective during the treatment of the above lesions. This case highlights the diversity of clinical manifestations of sarcoidosis and emphasizes the importance of its differential diagnosis and the periodical follow-up. These are crucial to physicians in the diagnosis and treatment of sarcoidosis.

Main Symptoms and Important Clinical Findings

A 30-year-old male complained about intermittent fever 3 years ago. A computed tomographic scan of the chest showed lymphadenopathy in the mediastinum and hilar regions. Routine blood tests showed leukopenia and mild anemia. The pathologic result of mediastinal lymph node biopsy was granulomatous lesions; thus, the patient was diagnosed with type II sarcoidosis without glucocorticoid therapy. In the following 2 years, the patient suffered from intermittent fever accompanied by dyspnea, fatigue, occasional cough, less sputum, and apparent weight loss. Abnormal physical examinations included leg ulcers and splenomegaly. Laboratory and physical tests revealed pancytopenia, polyserositis, and enlargement of lymph nodes. The pathological findings of leg ulceration, pleura, and left supraclavicular lymph node all suggested granulomas.

Diagnosis, Interventions, and Outcomes

It strongly suggested sarcoidosis since tuberculosis, lymphoma, and connective tissue disease were all excluded. Due to severe conditions and multiorgan involvement, we tried to provide methylprednisolone for this patient. After 9 months of oral glucocorticoids therapy, his subjective symptoms as well as hematological and radiological findings were all improved. His leg skin ulceration and scab were also completely disappeared.

Conclusion

Sarcoidosis has diverse clinical presentations, and many patients present with atypical symptoms. It needs to be timely identified by the clinician and carefully differentiated from other diseases with similar findings so as to make an accurate diagnosis. In this case, the patient had a poor clinical response to glucocorticoids in the early stage of treatment due to the severe condition and multi-organ involvement. It is worth noting that the patient had improved significantly after 9 months of treatment of corticosteroids, which suggested that follow-up is critical.

Atypical Sarcoidosis Diagnosed by Massive Splenomegaly

We examined a 22-year-old woman who was admitted to our hospital with abdominal distention. At 19 years of age, the patient presented with hepatosplenomegaly. She was examined several times in another hospital; however, the cause was unidentified. Our evaluation showed severe pancytopenia and a spleen 13×24 cm in size. The serum levels of angiotensin-converting enzyme and lysozyme were elevated. She was diagnosed with liver sarcoidosis based on non-caseating epithelioid granuloma in liver biopsy tissue. To improve the symptoms, splenectomy was performed, and her pancytopenia and symptoms improved. Sarcoidosis should be considered in cases of massive splenomegaly.

Host-microbe interactions in the pathogenesis and clinical course of sarcoidosis

Sarcoidosis is a rare inflammatory disease characterized by the development of granulomas in various organs, especially in the lungs and lymph nodes. Clinics of the disease largely depends on the organ involved and may range from mild symptoms to life threatening manifestations. Over the last two decades, significant advances in the diagnosis, clinical assessment and treatment of sarcoidosis have been achieved, however, the precise etiology of this disease remains unknown. Current evidence suggests that, in genetically predisposed individuals, an excessive immune response to unknown antigen/s is crucial for the development of sarcoidosis. Epidemiological and microbiological studies suggest that, at least in a fraction of patients, microbes or their products may trigger the immune response leading to sarcoid granuloma formation. In this article, we discuss the scientific evidence on the interaction of microbes with immune cells that may be implicated in the immunopathogenesis of sarcoidosis, and highlight recent studies exploring potential implications of human microbiota in the pathogenesis and the clinical course of sarcoidosis.

Immunogenetics of Disease-Causing Inflammation in Sarcoidosis

Sarcoidosis is a systemic inflammatory disorder characterised by tissue infiltration by mononuclear phagocytes and lymphocytes with associated non-caseating granuloma formation. Originally described as a disorder of the skin, sarcoidosis can involve any organ with wide-ranging clinical manifestations and disease course. Recent studies have provided new insights into the mechanisms involved in disease pathobiology, and we now know that sarcoidosis has a clear genetic basis largely involving human leukocyte antigen (HLA) genes. In contrast to Mendelian-monogenic disorders--which are generally due to specific and relatively rare mutations often leading to a single amino acid change in an encoded protein--sarcoidosis results from genetic variations relatively common in the general population and involving multiple genes, each contributing an effect of varying magnitude. However, an individual may have the necessary genetic profile and yet the disease will not develop unless an environmental or infectious factor is encountered. Genetics appears also to contribute to the huge variability in clinical phenotype and disease behaviour. Moreover, it has been established that sarcoidosis granulomatous inflammation is a highly polarized T helper 1 immune response that starts with an antigenic stimulus followed by T cell activation via a classic HLA class II-mediated pathway. A complex network of lymphocytes, macrophages, and cytokines is pivotal in the orchestration and evolution of the granulomatous process. Despite these advances, the aetiology of sarcoidosis remains elusive and its pathogenesis incompletely understood. As such, there is an urgent need for a better understanding of disease pathogenesis, which hopefully will translate into the development of truly effective therapies.

Interferon regulatory factor 5 polymorphisms in sarcoidosis

OBJECTIVE

Interferon regulatory factor 5 (IRF5) gene polymorphisms are associated with susceptibility to autoimmune diseases. The aim of this study is to determine the roles of IRF5 single-nucleotide polymorphisms (SNPs) in sarcoidosis.

METHODS

A total of 175 Japanese patients with biopsy-proven sarcoidosis and 150 sex-matched controls were genotyped for four IRF5 SNPs: rs729302A/C, rs2004640G/T, rs10954213A/G, and rs2280714G/A. The associations of these SNPs with susceptibility to sarcoidosis were examined.

RESULTS

Carriage of rs10954213A and rs2280714A conferred significant risks for sarcoidosis [carriage of rs10954213A: odds ratio (OR) = 1.96, 95% confidence interval (CI) = 1.15-3.33, P = 0.01, corrected P = 0.04; carriage of rs2280714A: OR = 1.97, 95% CI = 1.22-3.16, P = 0.005, corrected P = 0.02]. The haplotype carrying rs10954213A and rs2280714A (haplotype 2) was significantly associated with susceptibility to sarcoidosis (OR = 2.00, 95% CI = 1.24-3.24, P = 0.004, corrected P = 0.01). rs729302 and rs2004640 were not associated with susceptibility to sarcoidosis, whereas carriage of rs2004640G was protective against pulmonary hypertension (OR = 0.017, 95% CI = 0.002-0.15, P < 0.001, corrected P < 0.001).

CONCLUSION

A haplotype carrying two functional SNPs of IRF5, rs10954213A and rs2280714A, was associated with the risk of sarcoidosis in the Japanese population.

Pathogenesis of sarcoidosis

Sarcoidosis is a systemic granulomatous disorder of unknown origin. Recent research uncovered underlying immunological and genetic mechanisms, which will pave the way for more effective pharmaceutical studies. At present some of this knowledge is clinically exploited to monitor therapy and expected genetic progress will allow the development of prognostic genetic patterns or molecular signatures. Moreover, it has become obvious that several etiologic agents and cofactors will exist. These will be of animate and inanimate nature and their interplay with host mechanisms discussed in this review determines disease phenotypes.

Pathological and immunohistological findings and genetic aberrations of intestinal enteropathy-associated T cell lymphoma in Japan

AIMS

To elucidate the clinicopathological findings of primary intestinal enteropathy-associated T cell lymphoma (EATL) in Japan, a non-endemic area for coeliac disease.

METHODS AND RESULTS

Of the 24 cases, four (17%) had large-cell lymphoma (type I), and the remaining 20 (83%) had medium-sized lymphoma (type II). Lymphoma cells of the three type I cases were CD56-positive. Only one (4%) case showed typical CD56- and CD8-negative and CD30-positive type I EATL. In type II EATL, lymphoma cells of the 16 (80%) and 11 (55%) cases were positive for CD56 and CD8, respectively. Intramucosal tumour spreading and adjacent enteropathy-like lesions were detected in 15 (71%) and 16 (76%) of 21 cases, with a severe increase of intraepithelial lymphocytes (IELs) in 12 (57%). IELs of enteropathy-like lesions in five (24%) cases expressed T-bet, with no cases of CD30-positive IELs. Characteristic findings from comparative genomic hybridization of 15 cases indicated gains of 8q2 (47%), Xp (53%) and Xq (73%), but no gain of 9q3. Regarding, human leucocyte antigen (HLA) status, six cases examined did not express the DQB1*02 allele.

CONCLUSIONS

Japanese EATL exhibited different histology, cytogenetic findings and HLA status from those of typical type I EATL. The rare incidence of coeliac disease may influence the tumour cell characteristics of EATL and IELs.

Sarcoidosis HLA class II genotyping distinguishes differences of clinical phenotype across ethnic groups

The HLA class II (DRB1 and DQB1) associations with sarcoidosis have been studied by several groups but often without consistent results. In this paper, we consider the hypothesis that observed inconsistencies relate to distinct, genetically encoded disease phenotypes which differ in prevalence between centres. We therefore typed HLA-DRB1 and DQB1 in 340 UK, 139 Dutch and 163 Japanese sarcoidosis patients and, respectively, 354, 218 and 168 healthy controls from these populations. We applied consistent phenotyping and genotyping and investigated associations between HLA class II alleles and distinct disease phenotypes within and between ethnic groups. DRB1*01 and DQB1*0501 are protective against all manifestations of sarcoidosis. Lung-predominant sarcoidosis is associated with DRB1*12 and *14. Löfgren's syndrome is a common sarcoidosis phenotype in the Dutch and is strongly associated with the DRB1*0301 allele. This phenotype is not seen among the Japanese in whom DRB1*0301 is absent. The same allele is protective for UK uveitis. Sarcoid uveitis is common in Japan. The DRB1*04-DQB1*0301 haplotype is a risk factor for this disease manifestation in Japanese and UK subjects but protective for sarcoidosis overall. We show that distinct sarcoidosis phenotypes have similar genetic associations across ethnic groups. The disease case mix differs between centres and may be explained by different ethnic allelic frequencies.

Genetics of sarcoidosis

PURPOSE OF REVIEW

Increased familial occurrences as well as different disease modes in different ethnic groups suggest a genetic influence in sarcoidosis. Also, genetic analyses have revealed a number of chromosomal regions and specific genes associated with sarcoidosis. This review brings up some recent discoveries on the genetic contribution to sarcoidosis.

RECENT FINDINGS

As a more detailed clinical classification of patients is performed, stronger genetic associations between distinct clinical phenotypes and specific gene variants have been revealed. The strong association between human leucocyte antigen DRB10301/DQB10201 and good prognosis in patients with Löfgren's syndrome is one such recent example. Linkage studies have revealed certain chromosomal regions of interest and furthermore pointed out specific genes of interest, for example, a variant of the butyrophilin-like 2 gene.

SUMMARY

Sarcoidosis is a complex disease which is influenced by a multitude of genes and environmental factors. The strongest genetic associations are found within the human leucocyte antigen region, in which several specific human leucocyte antigen alleles clearly associate with disease risk and phenotype, but additional genes in the same region may turn out to be important as well. Future studies on large, clinically well defined patient cohorts will help to elucidate the genetic impact on sarcoidosis.