[Heterozygote forms of familial Mediterranean fever can be manifested in adults as myofacial pain syndrome]. / Heterozygote Formen des familiären Mittelmeerfiebers können beim Erwachsenen als myofasziales Schmerzsyndrom imponieren.

BACKGROUND: Familial Mediterranean fever (FMF) is a disease characterized by recurrent fever, serositis, arthritis and unspecific myalgia. It is prevalent among Mediterranean people and has been shown to be associated with mutations in the Mediterranean fever (MEFV) gene which, encodes pyrin a regulatory protein of the inflammasome. As heterozygous mutations in MEFV can be associated with only mild inflammatory symptoms, such as arthralgia or chronic fibromyalgic pain, FMF may be underdiagnosed in the current diagnostic work-up of musculoskeletal diseases. METHODS: The selection of patients was carried out according to the following criteria: myofacial pain syndrome, seronegative oligoarthralgia, a slight inflammatory constellation and ethnic origin from the Mediterranean area. When these criteria were fulfilled a molecular genetic investigation was carried out RESULTS: This article presents evidence that 9 out of 12 Mediterranean patients with recurrent myofascial pain syndrome and mild inflammation revealed heterozygote mutations in the MEFV gene and 7 of these patients benefitted from treatment with colchicine. DISCUSSION: As colchicine treatment not only improved the myofascial pain but also prevented FMF-associated amyloidosis and nephropathy, differential diagnosis of fibromyalgia in patients of Mediterranean origin should include FMF and a genetic screening of the MEFV locus.

Recurrence of high-grade cervical abnormalities following conservative management of cervical intraepithelial neoplasia grade 2.

OBJECTIVE: Conservative management of cervical intraepithelial neoplasia (CIN) grade 2 in women younger than 25 years may reduce overtreatment. However, long-term efficacy remains uncertain. This retrospective cohort study aimed to determine the rate of recurrence of high-grade abnormalities among young women with a history of CIN 2 that spontaneously regressed within 2 years and compare this with the rate of high-grade abnormality in similar women with an initial diagnosis of CIN 1. STUDY DESIGN: We identified all women aged younger than 25 years who were diagnosed with CIN 1 or CIN 2 between January 2005 and August 2009 within 2 colposcopy units. Follow-up data from the National Cervical Screening Programme were obtained to identify those women who developed recurrent high-grade lesions before October 2012. Comparisons were made using Cox proportional hazards regression. RESULTS: A total of 683 women were included: 106 with CIN 2 that spontaneously regressed, 299 with treated CIN 2, and 278 with conservatively managed CIN 1. Median follow-up was 4 years. There was no significant difference in the risk of development of high-grade abnormalities after 2 years between the spontaneously regressing CIN 2 and CIN 1 groups (P = .83). Women with treated CIN 2 had a significantly lower risk of recurrence than women with untreated CIN 2 (P = .01). CONCLUSION: CIN 2 that has spontaneously regressed appears to behave as a low-grade lesion. This study contributes to the growing body of evidence that careful observation of CIN 2 is an efficacious and appropriate initial management option for women aged younger than 25 years at diagnosis.

Is the treatment of CIN 2 always necessary in women under 25 years old?

OBJECTIVE: The purpose of this study was to review the outcome of conservatively managed cervical intraepithelial neoplasia (CIN) 2 in women <25 years old. STUDY DESIGN: This was a retrospective review that included women who were <25 years old with biopsy proven CIN2 between 2005 and 2009. Analysis was performed that compared women who had immediate treatment with women whose treatment was deferred >4 months. The primary outcome measure was spontaneous regression of CIN2. Secondary outcomes were treatment rates and loss to follow-up evaluation. RESULTS: Of the 452 women who were identified, 256 women (57%) received immediate treatment; 157 women (35%) met the definition for conservative management, and 39 women (9%) had unknown subsequent management. Of the 157 women who were managed conservatively, 98 women (62%) showed spontaneous regression, with a median of 8 months observation. No conservatively managed women progressed to cancer. CONCLUSION: Based on the 62% regression rate in this study, routine treatment may not be necessary for all women with CIN2 who are <25 years old.

[Chronic periaortitis]. / Chronische Periaortitis.

Chronic periaortitis is a rare fibroinflammatory disorder which affects the abdominal aorta and may spread into the retroperitoneum, often encasing the ureters. An aneurysma of the abdominal aorta and vasculitis of the thoracic aorta and of supra-aortic vessels may also coexist. Chronic periaortitis can be idiopathic or secondary to different triggers such as drugs, tumors and infections. Abdominal and/or low back pain is the hallmark symptom. Laboratory markers of inflammation are usually increased. The diagnosis rests on computerized tomography or magnetic resonance imaging, which typically show a retroperitoneal mass displacing the aorta anteriorly and the ureters medially. Positron-emission tomography may assist in defining disease activity and extension. Chronic periaortitis should be differentiated from other fibrosing disorders of various origins. Histology is required in atypical cases to secure the diagnosis. Treatment is based on high-dose steroids with a tapering scheme combined with immunosuppressive agents in refractory or relapsing disease. In case of ureter obstruction early DJ-catheter placement is required. Operative interventions to relieve ureter obstruction are rarely necessary provided immunosuppressive treatment is timely instituted.

Ultrasonography in the assessment of peripheral joint involvement in psoriatic arthritis : a comparison with radiography, MRI and scintigraphy.

The objective of our study was to investigate the role of musculoskeletal ultrasound (US) in the assessment of hand and foot small joints in psoriatic arthritis (PsA). Thirteen consecutive patients with PsA of hands or feet underwent B-mode US using a 9- to 13-MHz transducer and simultaneous magnetic resonance imaging (MRI), bone scintigraphy and radiography. US findings were compared with radiography, MRI and scintigraphy in 190, 182 and 109 joints, respectively. To assess the sensitivity and specificity of US, radiography was considered as gold standard for the detection of erosions and osteoproliferations and MRI as gold standard for the detection of joint effusion and synovitis. US, MRI and scintigraphy had a higher sensitivity in the detection of overall joint pathology than radiography in painful and/or swollen joints (71%, 72%, 82% vs 32%) and clinically unaffected joints (17%, 21%, 9% vs 2%). US and radiography detected more erosions and osteoproliferations than MRI, with low agreement between the methods in the detection of erosions. Radiography was superior to US in the visualisation of osteoproliferations. Joint effusions and/or synovitis were more frequently detected by MRI than US. Agreement between both imaging methods was better in carpal joints, carpometacarpal joint I, metacarpophalangeal (MCP)/metatarsophalangeal (MTP) joint I, II and V than in MCP/MTP III, IV, PIP and DIP joints. Compared with MRI, radiography and scintigraphy, the specificity of US ranges between 0.84 and 0.94, depending on the joint pathology. In conclusion, the diagnostic sensitivity of US in the detection of PsA-related synovitis of hands and feet is lower than MRI and depends on the joint region. However, the low cost and the acceptable specificity suggest that US is a useful imaging method in addition to radiography in PsA of hands and feet.

3-T MRI detects inflammatory stenosis of the vertebral artery in giant cell arteritis.

Giant cell arteritis (GCA) is a granulomatous vasculitis. Early diagnosis is important for the initiation of corticosteroid treatment because the arteritis can result in blindness. In most of the cases, the superficial cranial arteries are affected. However, extracranial involvement of various arteries is known. Here, we report a case of histologically proven GCA with an inflammatory stenosis of the right vertebral artery. For complete evaluation of the extension of the disease, an optimized protocol of high-resolution magnetic resonance imaging at 3 T in combination with contrast-enhanced magnetic resonance angiography was performed. This non-invasive method facilitates the differentiation of inflamed and healthy segments of small cranial arteries, may help to find appropriate sites for biopsy, and allows the assessment of affected extracranial vessels. In this patient case, even the cause of vertebral stenosis--inflammatory versus arteriosclerotic--could be elucidated.

Active vaccination in patients with common variable immunodeficiency (CVID).

Active vaccination of CVID patients with standard vaccines has rarely been studied in depth although some patients have been shown to develop transient vaccine-specific immunity. We addressed the question whether these patients can be identified by functional classification of their B cell subsets in vitro. Twenty-one CVID patients receiving regular IgG substitution were immunized with anti-peptide and anti-polysaccharide vaccines. Humoral vaccination responses were compared to the numbers of circulating memory B cells, CD21(low) B cells and the capacity to produce antibodies in vitro. Our findings allow four conclusions: (1) positive vaccination responses are not contradictory to the diagnosis of CVID; they occurred against polypeptide vaccines in 23% and against polysaccharide antigens in 18% of all vaccinations. (2) Class-switched antibody responses occur preferentially in patients of CVID group II. (3) A normal percentage of IgM memory B cells is necessary but not sufficient for a vaccination response to polysaccharide antigens. (4) Active vaccination in addition to IgG replacement therapy should be performed in patients of CVID type II - especially in case of vaccines for which passive protection cannot be guaranteed.

99mTechnetium pyrophosphate scintigraphy in the detection of skeletal muscle disease.

We aimed to assess the specificity and sensitivity of (99m)technetium pyrophosphate muscle scintigraphy in the diagnostic workup of patients with suspected myopathy. We reviewed the charts of 166 patients; 52% of the subjects had myalgias, 36% had muscle weakness, 45% had an elevated serum creatine kinase (CK), and 49% had an increased C reactive protein (CRP). Scintigraphy was positive in 34 patients (20%). The test was more sensitive in the presence of muscle weakness, elevated CK, or increased CRP. The presence of myalgias did not influence the odds. Sensitivity was 60% in patients with the final diagnosis of polymyositis, dermatomyositis, or inclusion body myositis, and 70% in noninflammatory myopathies. Eight percent had false positive scintigrams. In individuals with biopsy-proven myopathy (51 subjects), the diagnostic sensitivity was 43%, and its specificity was 60%. Low positive and high negative likelihood ratios (5.0 and 0.65, respectively) document an only limited diagnostic efficiency of (99m)Tc-PYP scintigraphy in the evaluation of inflammatory and noninflammatory myopathies and suggest that the test is not helpful in the routine diagnostic workup of muscle complaints, even after a priori selection of patients for CK plus CRP abnormalities.

Analgesic and disease modifying effects of interferential current in psoriatic arthritis.

Interferential current (IFC) was suggested to improve the skin manifestations of psoriasis vulgaris, possibly by enhancing the intracellular concentration of cyclic AMP. We assessed the efficacy of IFC on psoriatic arthritis (PsA). Nine consecutive patients were analyzed at baseline and after 16 weeks of IFC therapy. Bipolar IFC was applied twice daily to hands, feet plus all affected joints. IFC improved SF-36 assessed body pain, but not other SF-36 subscales. Morning stiffness, tender joint counts, and physician assessed disease activity improved. In contrast, visual analogue scale assessed pain, CRP and ESR measurements were unchanged. MRI of the most affected hand or foot documented a tendency towards worsened tendinitis, soft tissue swelling, and new joint space narrowing and erosions. Bone scintigraphy showed a trend towards deterioration. New joints became inflamed within treated sites. Thus IFC has analgesic effects in PsA, but does not have a satisfactory disease modifying effect.

Mutations in TNFRSF13B encoding TACI are associated with common variable immunodeficiency in humans.

The functional interaction of BAFF and APRIL with TNF receptor superfamily members BAFFR, TACI and BCMA is crucial for development and maintenance of humoral immunity in mice and humans. Using a candidate gene approach, we identified homozygous and heterozygous mutations in TNFRSF13B, encoding TACI, in 13 individuals with common variable immunodeficiency. Homozygosity with respect to mutations causing the amino acid substitutions S144X and C104R abrogated APRIL binding and resulted in loss of TACI function, as evidenced by impaired proliferative response to IgM-APRIL costimulation and defective class switch recombination induced by IL-10 and APRIL or BAFF. Family members heterozygous with respect to the C104R mutation and individuals with sporadic common variable immunodeficiency who were heterozygous with respect to the amino acid substitutions A181E, S194X and R202H had humoral immunodeficiency. Although signs of autoimmunity and lymphoproliferation are evident, the human phenotype differs from that of the Tnfrsf13b-/- mouse model.

Measurement of peripheral B cell subpopulations in common variable immunodeficiency (CVID) using a whole blood method.

Recent reports have described reduced populations of CD27+ memory B cells and increased percentages of undifferentiated B cells in peripheral blood of patients with common variable immunodeficiency (CVID). This work has prompted two attempts to classify CVID based on rapid flow cytometric quantification of peripheral blood memory B cells and immature B cells. Evidence to support the hypothesis that such in vitro B cell classification systems correlate with clinical subtypes of CVID is being sought. For the classification to be useful in routine diagnosis, it is important that the flow cytometric method can be used without prior separation of peripheral blood mononuclear cells (PBMC). We have examined 23 CVID patients and 24 controls, using both PBMC and whole blood, and find an excellent correlation between these methods. The reproducibility of the method was excellent. We classified the CVID patients by all three of the existing classifications, including secretion of immunoglobulin by B cells in vitro as described by Bryant, as well as the more recent flow cytometric classification methods. Only one patient changed classification as a result of using whole blood.

Autologous stem cell transplantation in the treatment of systemic sclerosis: report from the EBMT/EULAR Registry.

OBJECTIVE: To analyse the durability of the responses after haematopoietic stem cell transplantation (HSCT) for severe systemic sclerosis (SSc) and determine whether the high transplant related mortality (TRM) improved with experience. This EBMT/EULAR report describes the longer outcome of patients originally described in addition to newly recruited cases. METHODS: Only patients with SSc, treated by HSCT in European phase I-II studies from 1996 up to 2002, with more than 6 months of follow up were included. Transplant regimens were according to the international consensus statements. Repeated evaluations analysed complete, partial, or non-response and the probability of disease progression and survival after HSCT (Kaplan-Meier). RESULTS: Given as median (range). Among 57 patients aged 40 (9.1-68.7) years the skin scores improved at 6 (n = 37 patients), 12 (n = 30), 24 (n = 19), and 36 (n = 10) months after HSCT (p<0.005). After 22.9 (4.5-81.1) months, partial (n = 32) or complete response (n = 14) was seen in 92% and non-response in 8% (n = 4) of 50 observed cases. 35% of the patients with initial partial (n = 13/32) or complete response (n = 3/14) relapsed within 10 (2.2-48.7) months after HSCT. The TRM was 8.7% (n = 5/57). Deaths related to progression accounted for 14% (n = 8/57) of the 23% (n = 13/57) total mortality rate. At 5 years, progression probability was 48% (95% CI 28 to 68) and the projected survival was 72% (95% CI 59 to 75). CONCLUSION: This EBMT/EULAR report showed that response in two thirds of the patients after HSCT was durable with an acceptable TRM. Based on these results prospective, randomised trials are proceeding.

Release of endogenous anti-inflammatory complement regulators FHL-1 and factor H protects synovial fibroblasts during rheumatoid arthritis.

Rheumatoid arthritis is a chronic inflammatory disease of unknown aetiology predominantly affecting cells and tissues of synovial joints. Here we show that the two important complement regulators FHL-1 and factor H play a protective anti-inflammatory role in rheumatoid arthritis. Expression analyses at the mRNA- and protein level show in vitro expression and secretion of both regulators by synovial fibroblasts derived from patients with rheumatoid arthritis. Similarly the two regulators are synthesized in vivo in diseased synovial tissue, and in particular synovial lining cells express high levels of FHL-1. The anti-inflammatory role of these regulators in rheumatoid arthritis is highlighted by their induction with IFN-gamma and dexamethasone, whilst the pro-inflammatory cytokine TNF-alpha had no effect. Transient transfection experiments with various FHL-1/factor H promoter-luciferase reporter constructs into cells of distinct origin show independent cell and tissue specific promoter regulated transcription of these two regulators. The inducible expression, specifically of FHL-1 has physiological consequences. By binding directly to surfaces the released proteins protect cells from inflammatory damage and complement-mediated cell lysis. This study shows a novel protective and anti-inflammatory role of the two important complement regulators FHL-1 and factor H in rheumatoid arthritis and suggests a disease controlling role of the two proteins.

Human recombinant interferon alfa-2a for the treatment of Behçet's disease with sight threatening posterior or panuveitis.

BACKGROUND: Behçet's disease is a multisystem vasculitis of unknown origin. Standard treatment mainly comprises systemic immunosuppressive agents. Ocular involvement, mostly posterior uveitis with retinal vasculitis, leads to blindness in 20-50% of the involved eyes within 5 years. The efficacy of interferon alfa-2a was studied in patients with sight threatening posterior uveitis or retinal vasculitis. METHODS: 50 patients were included in this open, non-randomised, uncontrolled prospective study. Recombinant human interferon alfa-2a (rhIFNalpha-2a) was applied at a dose of 6 million units subcutaneously daily. Dose reduction was performed according to a decision tree until discontinuation. Disease activity was evaluated every 2 weeks by the Behçet's disease activity scoring system and the uveitis scoring system. RESULTS: Response rate of the ocular manifestations was 92% (three non-responder, one incomplete response). Mean visual acuity rose significantly from 0.56 to 0.84 at week 24 (p<0.0001). Posterior uveitis score of the affected eyes fell by 46% every week (p<0.001). Remission of retinal inflammation was achieved by week 24. Mean Behçet's disease activity score fell from 5.8 to 3.3 at week 24 and further to 2.8 at week 52. After a mean observation period of 36.4 months (range 12-72), 20 patients (40%) are off treatment and disease free for 7-58 months (mean 29.5). In the other patients maintenance IFN dosage is three million units three times weekly. CONCLUSIONS: rhIFNalpha-2a is effective in ocular Behçet's disease, leading to significant improvement of vision and complete remission of ocular vasculitis in the majority of the patients.

Infectious CNS disease as a differential diagnosis in systemic rheumatic diseases: three case reports and a review of the literature.

BACKGROUND: Immunosuppressive treatment of rheumatic diseases may be associated with several opportunistic infections of the brain. The differentiation between primary central nervous system (CNS) involvement and CNS infection may be difficult, leading to delayed diagnosis. OBJECTIVE: To differentiate between CNS involvement and CNS infection in systemic rheumatic diseases. METHODS AND RESULTS: Three patients with either longstanding or suspected systemic rheumatic diseases (systemic lupus erythematodes, Wegener's granulomatosis, and cerebral vasculitis) who presented with various neuropsychiatric symptoms are described. All three patients were pretreated with different immunosuppressive drugs (leflunomide, methotrexate, cyclophosphamide) in combination with corticosteroids. Magnetic resonance imaging of the brain was suggestive of infectious disease, which was confirmed by cerebrospinal fluid analysis or stereotactic brain biopsy (progressive multifocal leucoencephalopathy (PML) in two and nocardiosis in one patient). DISCUSSION: More than 20 cases of PML or cerebral nocardiosis in patients receiving corticosteroids and cytotoxic drugs for rheumatic disease have been reported. The clinical aspects of opportunistic CNS infections and the role of brain imaging, cerebrospinal fluid analysis and stereotactic brain biopsy in the differential diagnosis are reviewed.

Impaired up-regulation of CD70 and CD86 in naive (CD27-) B cells from patients with common variable immunodeficiency (CVID).

CVID is characterized by reduced serum levels of all switched immunoglobulin isotypes (IgG, IgA, IgE) predisposing patients to recurrent infections of their respiratory and gastrointestinal tract. Correspondingly, most CVID patients exhibit a severely decreased proportion of class switched memory B cells (CD19+CD27+IgD-IgM-IgG+ or IgA+) in their peripheral blood (CVID type I). We previously identified a subgroup of CVID patients showing a significantly reduced expression of CD86 and CD137 following activation in vitro of PBMC or purified B cells (CD19+) with anti-IgM plus IL-2. Here we extend our previous studies by asking whether highly purified, cell-sorted naive B cells show already an expression defect of B cell surface molecules relevant in activation (CD39, CD69), differentiation (CD24, CD27, CD38) or T-B interaction (CD25, CD70, CD86). We stimulated cell-sorted, naive B cells (CD19+CD27-IgM+IgDhighIgG-IgA-) from 10 CVID patients and 10 healthy controls for 4 days with anti-IgM plus IL-2 in the absence or presence of autologous CD4+ T cells and measured the expression of the referred surface molecules. Based on reduced or normal numbers of switched memory B cells the CVID patients had previously been classified into eight type I patients and two type II patients, respectively. Interestingly, only the molecules CD25, CD70 and CD86, all relevant in cognate T-B interaction, showed a significantly lower expression in naive B cells from CVID patients compared to controls. While coculture with autologous CD4+ T cells normalized the CD25 expression, CD70 and CD86 expression remained subnormal, notably in the eight CVID patients of type I. These findings strongly suggest an intrinsic signalling or expression defect for CD70/CD86 at the level of naive B cells in type I CVID patients.

No difference in the incidences of vasculitides between north and south Germany: first results of the German vasculitis register.

OBJECTIVE: To register all newly diagnosed patients with primary systemic vasculitis (PSV) in two large regions in north and south Germany. METHODS: Between 1 January 1998 and 31 December 1999, all newly diagnosed cases of PSV, as defined by the Chapel Hill Consensus Conference 1992, were identified in two large mixed rural/urban regions in north and south Germany with a combined population of 4,880,543, for a population-based prospective study. The following sources were used: (i) all departments of every hospital, including their out-patient clinics; (ii) all departments of pathology; and (iii) all reference immunological laboratories serving the catchment area. All cases were re-evaluated by the authors. RESULTS: Over the whole period, 473 individuals were registered as having a new PSV. The incidence rates for all PSV were 54 cases per 1,000,000 inhabitants in the north and 48 in the south in 1998, and 48 and 41 respectively in 1999. People 50 yr and older had a three- to five-fold higher risk of getting PSVs than those under 50 yr. The incidences of antineutrophil cytoplasmic antibody (ANCA)-associated PSVs [Wegener's granulomatosis (WG), microscopic polyangiitis (MPA) and Churg-Strauss syndrome (CSS)] remained stable in both regions, at about 9.5 per 1,000,000 annually. The incidence of WG was two to three times greater than those of MPA and CSS. There was no difference in incidence rates between north and south Germany. CONCLUSION: First results from a population-based vasculitis register serving nearly 5,000,000 inhabitants in north and south Germany revealed no regional differences in the incidence of all PSVs between north and south. The incidence rates of ANCA-associated PSVs, such as WG and MPA, were lower than those in the UK and Norway but higher than that in Spain.

Short-term treatment of primary fibromyalgia with the 5-HT3-receptor antagonist tropisetron. Results of a randomized, double-blind, placebo-controlled multicenter trial in 418 patients.

We investigated the efficacy and tolerability of short-term treatment with tropisetron, a selective, competitive 5-HT3-receptor antagonist in fibromyalgia. The trial was designed as a prospective, multicenter, double-blind, parallel-group, dose-finding study. We randomly assigned 418 patients suffering from primary fibromyalgia to receive either placebo, 5 mg, 10 mg or 15 mg tropisetron once daily for 10 days. Clinical response was measured by changes in pain score, visual analog scale, tender point count and ancillary symptoms. Responders were prospectively defined as patients showing a 35% or higher reduction in pain score. Treatment with 5 mg tropisetron resulted in a significantly higher response rate (39.2%) than placebo (26.2%) (p < 0.05). In the visual analog scale, the group administered 5 mg tropisetron showed a significant improvement (p < 0.05) and the group administered 10 mg tropisetron showed a nonsignificant clinical benefit. The number of painful tender points was significantly reduced (p = 0.002) in the 5 mg tropisetron group. Regarding ancillary symptoms, the 5 mg tropisetron group showed a significant improvement (p < 0.05) in sleep and dizziness. The patients' overall assessment of efficacy was significantly higher for 5 mg (p = 0.016) and 10 mg (p = 0.002) tropisetron than for placebo. The safety and tolerability of tropisetron was good; gastrointestinal tract symptoms were the most frequently reported adverse events. Short-term treatment of fibromyalgia patients with 5 mg tropisetron for 10 days proved to be efficacious and well tolerated. In this study a bell-shaped dose-response curve was seen.

["Catastrophic systemic lupus erythematosus" with Rosai-Dorfman sinus histiocytosis. Successful treatment with anti-CD20/rutuximab]. / "Katastrophaler SLE" mit Rosai-Dorfman-Sinushistiozytose. Erfolgreiche Behandlung mit Anti-CD20/Rituximab.

HISTORY AND ADMISSION FINDINGS: A 59-year old woman was admitted with a four-month history of polyarthritis, myalgias and photosensitivity insufficiently responsive to methotrexate, corticosteroids and azathioprin. On physical examination she presented with symmetric ankle edema, polyserositis, petechial bleeding and swelling of cervical, axillary and inguinal lymph nodes. INVESTIGATIONS: Laboratory analysis revealed a trilinear cytopenia without signs of hemolysis. Acute phase proteins were elevated. Furthermore antinuclear antibodies, anti-phospholipid IgM antibodies, hypocomplementemia, a spurious IgGkappa paraprotein were noted. CT scans confirmed lymphadenopathy and revealed a pleural and pericardial effusion. Bone marrow biopsy showed marked hypercellularity and polyclonal plasmocytosis. Based on these findings systemic lupus erythematosus was initially suspected. However when abdominal MRI showed a retroperitoneal mass, an extensive histological workup, which also included lymph nodes and spleen, revealed numerous plasma cells and histiocytes in dilated sinuses, diagnostic of Rosai-Dorfman sinus histiocytosis. TREATMENT AND COURSE: High dose corticosteroids, intravenous gamma-globulin and repeated courses of cyclophosphamide failed to improve the pancytopenia, as did splenectomy. The patient was given the anti-CD20 monoclonal antibody Rituximab and all signs and symptoms improved dramatically. 18 months after the last treatment, the patient is in complete clinical and hematological remission. CONCLUSIONS: Sinus histiocytosis of Rosai/Dorfman can be associated with or mimic severe SLE. Rituximab, an anti-CD20 monoclonal antibody, may improve the antibody-mediated pathogenetic mechanism underlying both entities.