Analysis of B-cell clonality in the hepatic tissue of patients with Sjögren's syndrome

Role of immunoglobulin heavy and light chain gene rearrangement analysis in differentiating between benign and malignant bone marrow B-cell lymphoid aggregates

Lymphoid aggregates are found in a minority of bone marrow biopsy and aspirate specimens, and when present, the distinction between benign and malignant aggregates can represent a diagnostic challenge. Morphologic and immunophenotypic evaluation of the aggregates can aid in that distinction but in a few cases, detection of immunoglobulin heavy chain (IGH) and kappa light chain (IGK) gene rearrangements may be needed to rule in or out a malignant disease process. We studied the role of testing for IGH/IGK rearrangements in the distinction between benign and malignant B cell-predominant lymphoid aggregates. Only a few studies have addressed this issue and most lacked an adequate number of cases for establishing statistical significance. Our study retrospectively evaluated 120 bone marrow aspirate and biopsy specimens, 79 cases originally diagnosed with benign lymphoid aggregates [4,5], and 41 demonstrating a B-cell lymphoma with malignant aggregates. Immunohistochemical stains were performed on all cases in our study and flow cytometry results were available in the vast majority of cases (98%). All patients included in our study but 9 had at least 2 years of clinical follow-up information. Of the malignant lymphoma cases, IGH/IGK rearrangements were demonstrated by polymerase chain reaction in 60% of the cases. Moreover, clonal rearrangements were identified in 15% of the cases with benign aggregates. After at least 2 years of follow-up, only one case with a positive clonality study occurring in the setting of morphologically benign-appearing bone marrow lymphoid aggregates experienced a relapse of non-Hodgkin lymphoma. Molecular analysis of the IGH and IGK genes may have utility in confirming the presence of malignancy in bone marrow aspirates and biopsy specimens. False-negative results, however, are possible due to testing limitations and sampling issues. Moreover, patients with conditions such as autoimmune disorders or infectious diseases are shown to also develop clonal B-cell lymphoid aggregates. As a result, we recommend a thorough morphological examination, informative immunohistochemical staining, accurate flow cytometric analysis, and current IGH/IGK rearrangement testing when evaluating bone marrow specimens containing B cell-predominant lymphoid aggregates, with the knowledge that molecular clonality results should be carefully interpreted in the context of morphological and immunophenotypic findings to prevent misdiagnosis.

Co-development of autoimmune hepatitis and Sjögren's syndrome triggered by the administration of herbal medicines

Autoimmune hepatitis (AIH) has been reported in association with Sjögren's syndrome (SS). Drug-induced AIH has been rarely reported. A rare case of the co-development of AIH and SS in a 53-year-old woman after the consumption of herbal medicines is described. After admission, the patient complained of dryness in her mouth, and she was subsequently diagnosed with SS, which had not been detected previously. The patient's bilirubin and aminotransferase levels initially decreased following conservative management; however, they later began to progressively increase. A diagnosis of AIH was made based on the scoring system proposed by the International Autoimmune Hepatitis Group. The patient was administered a combination of prednisolone and azathioprine, and the results of follow-up liver-function tests were found to be within the normal range. This is an unusual case of AIH and SS triggered simultaneously by the administration of herbal medicines.

Malignant lymphoma in primary Sjögren's syndrome: an update on the pathogenesis and treatment

OBJECTIVES

Sjögren's syndrome (SS), a chronic autoimmune disorder, particularly compromises the function of exocrine glands. Its association with lymphoma is well documented. Our aim was to systematically review the molecular, clinical, histopathologic, and therapeutic aspects of these SS-related malignant lymphoproliferations.

METHODS

The literature was searched for original articles published between 1968 and 2012 focusing on the risk factors for lymphoma development in Sjögren's syndrome using MEDLINE and PubMed. The search terms we used were "Sjögren's syndrome," "lymphoma," and "risk factors." All papers identified were English-language, full-text papers.

RESULTS

A low-grade marginal-zone lymphoma related to mucosa-associated lymphoid tissue is the commonest lymphoid neoplasia in SS. The majority of SS-associated lymphomas are characterized by localized stage, indolent clinical course, and recurrence in other extranodal sites. Although the transition from a chronic inflammatory condition to malignant lymphoma is a multistep process that is yet poorly understood, there is increasing evidence that chronic antigenic stimulation by an exoantigen or autoantigens plays an essential role in the development of SS-associated lymphoproliferation.

CONCLUSIONS

This review discusses the pathogenetic aspects of lymphomagenesis in SS. Recent advances in the treatment of lymphoma in SS are also stated.

Gastrointestinal and hepatic manifestations of Sjogren syndrome

Sjogren syndrome (SS) is an autoimmune disease that affects exocrine glands and therefore may affect the gastrointestinal system, from the mouth, esophagus, and bowel to the liver and pancreas. Oral involvement in SS is mainly characterized by dryness, with a wide spectrum of symptoms, from mild-to-severe xerostomia with dysgeusia and tooth decay. The dysphagia, although common, does not correlate with the reduced salivary flow rate or the dysmotility that may be present. Dyspepsia, found in up to 23% of patients, may be associated with gastritis, reduced acid production, and antiparietal cell antibodies, but rarely pernicious anemia. Pancreatic involvement, although rare, includes pancreatitis and pancreatic insufficiency. The most common causes of liver disease are primary biliary cirrhosis, autoimmune hepatitis, nonalcoholic fatty liver disease, and hepatitis C virus (HCV). Although abnormal liver tests are found in up to 49% of patients, they are usually mild. Although sicca syndrome, abnormal histology of the salivary glands, and abnormal sialograms are common in primary biliary cirrhosis, the antibodies to Ro/SSA or La/SSB antigens are infrequent. Xerostomia, sialadenitis, abnormal salivary flow rates, and abnormal Schirmer test in HCV vary widely among the studies, although the antibodies to Ro/SSA or La/SSB are only 1%. Several studies show that HCV is in saliva, although how this may impact sicca syndrome or SS in HCV is unclear. SS as a disease of exocrine glands affects many parts of the gastrointestinal system.

The many faces of Janus kinase

Janus kinases have proved to be essential for many immunological processes but there is growing evidence that they also play a critical role in pathogenesis of many diseases including inflammatory diseases and cancer where they promote multiple steps of tumorigenesis. Several companies are in late stage clinical programs for the development of JAK kinase inhibitors and the first small molecule JAK inhibitor, Jakafi® (ruxolitinib) has been just approved for treatment of myeloproliferative neoplasms. Several other molecules are on the rise to treat arthritis, psoriasis and multiple types of cancer. This commentary will provide a review of the JAK kinase field as it pertains to small molecule inhibition for the treatment of cancer and autoimmune diseases with an emphasis on JAK2. The use of experimental and clinical inhibitors of JAK will be discussed for solid tumor and hematological malignancies, lupus, arthritis, colitis, neurological disorders, pain, diabetes and cardiovascular disease. In addition, it will review current paradigms in the field and treatment programs which could be complemented by small molecule inhibitors of Janus kinase.

An unusual self-limited clonal Mott cell proliferation with lymphoplasmacytic lymphoma-like features in a child with the Wiskott-Aldrich syndrome and Von Recklinghausen's neurofibromatosis

Patients with the Wiskott-Aldrich syndrome are at high risk for development of lymphomas, which are predominantly extranodal and of the immunoblastic type. We present a case of a self-limited lymphoproliferation with features of lymphoplasmacytic lymphoma arising in a patient with the Wiskott-Aldrich syndrome. The patient also had stigmata of von Recklinghausen's neurofibromatosis. The tumor was composed of CD138+, IgGkappa+, CD20-, PAX-5- Mott cells and CD5-, CD10-, CD19+, CD20+, CD43- small lymphoid B-cells that partially expressed CD23. The lymphadenopathy spontaneously resolved after a period of less than a year, and the patient had remained free of detectable lymphoproliferation for almost 4 years. He then developed Burkitt's lymphoma of the left parapharyngeal space. It is remarkable that both known lymphoproliferations with features of lymphoplasmatic lymphoma arising in patients with the Wiskott-Aldrich syndrome, this one and the previously described one, have spontaneously resolved. This observation is truly intriguing and requires further clinico-pathologic studies.

Will Jill come tumbling after? The case for a JAK2-type mutation as a prequel to the connective tissue disorders

The JAK2 [V617F] mutation has recently been recognised as critical to the pathogenesis of the myeloproliferative disorders (MPDs). Thus, a common mutation affecting a haematopoietic precursor stem cell is capable of giving rise to diverse clinical phenotypes. In this hypothesis paper, we propose that a similar mutation affecting a stem cell precursor, most likely of the B cell lineage, could underlie the development of the connective tissue disorders which could be regarded as "lymphoproliferative" disorders. Consistent with this hypothesis is the observation that there are similarities between the myeloproliferative disorders and the connective tissue disorders in terms of their biological behaviour. Diseases within each family can transform into each other and sometimes into haematological malignancies (most often B cell origin non-Hodgkins lymphoma for the connective tissue disorders and acute myeloid leukemia for the myeloproliferative disorders). The timecourse for development of the connective tissue disorders involves a long latent period when autoantibodies are present (anti-CCP and ANA) possibly reflecting production by a B cell clone. A similar time-dependent increase in clonal dominance has been described in erythroblastic clones taken from the bone marrow of polycythemia vera patients, long before the onset of clinical disease. Evidence of B cell clonality has been described in bone marrow samples from rheumatoid arthritis patients and from glandular biopsies from those with Sjogren's syndrome. Moreover, pseudofollicles containing activated B cells are features of rheumatoid synovial membrane and have also recently been described in subchondral bone where they are associated with macrophages, T cells and osteoclasts. The success of B cell depletion therapy in rheumatoid arthritis and systemic lupus erythematosus is also strong circumstantial evidence for this hypothesis.

Bone marrow trephines containing lymphoid aggregates from patients with rheumatoid and other autoimmune disorders frequently show clonal B-cell infiltrates

In bone marrow trephines, morphological and immunohistochemical criteria may not be sufficient to discriminate reactive from malignant lymphoid infiltrates. The aim of this study was to determine whether the detection of clonal immunoglobulin heavy chain (IGH) gene rearrangements is a reliable and specific marker for malignant B-cell clones in bone marrow biopsies. Bone marrow trephines with infiltration by different types of low-grade B-cell non-Hodgkin lymphoma (n = 32), reactive lymphoid hyperplasia (n = 18), and reactive lymphoid aggregates (n = 15), including 5 patients with rheumatoid or other autoimmune disorders, were analyzed by morphology, immunohistochemistry, IGH gene rearrangement (polymerase chain reaction), and DNA sequence analysis in selected cases. In 22 (68.8%) of 32 patients with B-cell non-Hodgkin lymphoma, a clonal IGH gene rearrangement was detected. Of the reactive cases, 1 of 18 patients with lymphoid hyperplasia demonstrated clonality, and 9 (60%) of 15 patients with reactive lymphoid aggregates gave a clonal result (GeneScan analysis). DNA sequence analysis was performed in 7 of the latter patients confirming clonality in 6. Four of the patients with B-cell clonality had an autoimmune disorder. None of these patients developed a malignant lymphoma during follow-up. Thus, the molecular detection of a clonal rearrangement of the IGH gene may support the diagnosis of a malignant lymphoma infiltrating the bone marrow. However, morphologically and immunohistochemically benign lymphoid aggregates might also harbor B-cell clones especially in patients with autoimmune disorders. Therefore, the detection of clonality has to be interpreted with utmost care and does not qualify for the unequivocal diagnosis of a malignant B-cell lymphoma.

Autoimmune Pancreatitis: Frequency, IgG4 Expression, and Clonality of T and B Cells

Autoimmune pancreatitis (AIP) is a newly recognized disease. The presence of IgG4 positive plasma cells is thought to be of diagnostic help. In a surgical series of chronic pancreatitis cases, we determined the relative frequency of AIP before and after 1990, analyzed the diagnostic significance of IgG4 expression and examined the presence of oligoclonal T or B-cell populations. The histopathology of 202 surgical specimens of chronic pancreatitis removed between 1975 and 2004 was reviewed and 2 groups were distinguished, 1 of AIP cases and the other of nonautoimmune chronic pancreatitis (non-AIP CP). The intensity of infiltration of pancreatic tissue by IgG4 positive plasma cells and other immune cells was studied immunohistochemically. Finally, T and B-cell clonality was tested by polymerase chain reaction-based analysis. Except for 1 case in 1978, all cases of AIP were observed after 1990. IgG4 positive plasma cells were detected in 72.5% of AIP cases and in 63.1% of non-AIP CP cases. More than 20 cells per high power field were only seen in AIP (sensitivity 43%, specificity 100%). This finding was associated with higher age and grade. Polyclonal T and B-cell populations were found in both AIP and non-AIP CP except for 1 AIP case showing an oligoclonal IgGH-FR3 gene rearrangement. AIP seems to have increased considerably in frequency in the last 2 decades. High density infiltrates of IgG4 positive plasma cells are diagnostic for AIP, but are seen in less than half of the cases. T or B-cell oligoclonality could not be established as a feature of AIP.

[Liver involvement in primary Sjogren's syndrome]

PURPOSE

To determine the prevalence of liver involvement in patients with primary Sjogren's syndrome (SS) and to evaluate the association of this complication with other extra-glandular manifestations and serologic markers.

METHODS

We examined 155 Japanese patients (150 women and 5 men, mean age 66.6 years) who met the European Epidemiology Center Criteria for primary SS. Liver involvement was considered present when abnormal liver function tests (AST, ALT, ALP, GTP, or bilirubin) were detected more than three times.

RESULTS

20 patients (13%) had liver involvement including 2% with clinically overt liver disease. The causes of liver involvement were primary biliary cirrhosis (PBC) 6, autoimmune hepatitis (AIH) 2, hepatitis C virus (HCV) infection 2, concurrence of AIH and HCV infection 1, fatty liver 1. In 8 patients, the cause remained unclear. Of 6 patients complicated with PBC, four patients had PBC-specific antimitochondrial antibodies (AMA). Liver dysfunction was transient in two patients. Hepatocelluar carcinoma developed in a patient whose liver involvement was due to AIH and HCV. Patients with liver involvement were more likely to have cutaneous and neurological manifestations, when compared to SS without liver involvement. A positive antinuclear antibody, rheumatoid factor, and anticentromere antibody were also associated with liver involvement. Other autoantibodies did not correlate with the prevalence of liver involvement.

CONCLUSION

Although symptomatic liver involvement is rare in SS patients, asymptomatic liver involvement is common. Clinicians must be aware of the possibility of liver involvement so that it can be treated as soon as possible.