Late-onset enteric virus infection associated with hepatitis (EVAH) in transplanted SCID patients.

BACKGROUND: Allogenic hematopoietic stem cell transplantation (HSCT) and gene therapy (GT) are potentially curative treatments for severe combined immunodeficiency (SCID). Late-onset posttreatment manifestations (such as persistent hepatitis) are not uncommon. OBJECTIVE: We sought to characterize the prevalence and pathophysiology of persistent hepatitis in transplanted SCID patients (SCIDH+) and to evaluate risk factors and treatments. METHODS: We used various techniques (including pathology assessments, metagenomics, single-cell transcriptomics, and cytometry by time of flight) to perform an in-depth study of different tissues from patients in the SCIDH+ group and corresponding asymptomatic similarly transplanted SCID patients without hepatitis (SCIDH-). RESULTS: Eleven patients developed persistent hepatitis (median of 6 years after HSCT or GT). This condition was associated with the chronic detection of enteric viruses (human Aichi virus, norovirus, and sapovirus) in liver and/or stools, which were not found in stools from the SCIDH- group (n = 12). Multiomics analysis identified an expansion of effector memory CD8+ T cells with high type I and II interferon signatures. Hepatitis was associated with absence of myeloablation during conditioning, split chimerism, and defective B-cell function, representing 25% of the 44 patients with SCID having these characteristics. Partially myeloablative retransplantation or GT of patients with this condition (which we have named as "enteric virus infection associated with hepatitis") led to the reconstitution of T- and B-cell immunity and remission of hepatitis in 5 patients, concomitantly with viral clearance. CONCLUSIONS: Enteric virus infection associated with hepatitis is related to chronic enteric viral infection and immune dysregulation and is an important risk for transplanted SCID patients with defective B-cell function.

Allogeneic stem cell transplantation compared to conservative management in adults with inborn errors of immunity.

Allogeneic hematopoietic stem cell transplantation (alloSCT) is curative for severe inborn errors of immunity (IEIs), with recent data suggesting alloSCT in adulthood is safe and effective in selected patients. However, questions remain regarding the indications for and optimal timing of transplant. We retrospectively compared outcomes of transplanted vs matched nontransplanted adults with severe IEIs. Seventy-nine patients (aged ≥ 15 years) underwent alloSCT between 2008 and 2018 for IEIs such as chronic granulomatous disease (n = 20) and various combined immune deficiencies (n = 59). A cohort of nontransplanted patients from the French Centre de Référence Déficits Immunitaires Héréditaires registry was identified blindly for case-control analysis, with ≤3 matched controls per index patient, without replacement. The nontransplanted patients were matched for birth decade, age at last review greater than index patient age at alloSCT, chronic granulomatous disease or combined immune deficiencies, and autoimmune/lymphoproliferative complications. A total of 281 patients were included (79 transplanted, 202 nontransplanted). Median age at transplant was 21 years. Transplant indications were mainly lymphoproliferative disease (n = 23) or colitis (n = 15). Median follow-up was 4.8 years (interquartile range, 2.5-7.2). One-year transplant-related mortality rate was 13%. Estimated disease-free survival at 5 years was higher in transplanted patients (58% vs 33%; P = .007). Nontransplanted patients had an ongoing risk of severe events, with an increased mean cumulative number of recurrent events compared with transplanted patients. Sensitivity analyses removing patients with common variable immune deficiency and their matched transplanted patients confirm these results. AlloSCT prevents progressive morbidity associated with IEIs in adults, which may outweigh the negative impact of transplant-related mortality.

Clonal haematopoiesis of indeterminate potential and cardiovascular events in systemic lupus erythematosus (HEMATOPLUS study).

OBJECTIVE: The detection of somatic mutations among the genes of myeloid cells in asymptomatic patients-defining clonal haematopoiesis of indeterminate potential (CHIP)-is associated with a predisposition to cardiovascular events (CVEs) in the general population. We aimed to determine whether CHIP was associated with CVEs in SLE patients. METHODS: The study is an ancillary study of the randomized, double-blind, placebo-controlled, multicentre PLUS trial conducted from June 2007 through August 2010 at 37 centres in France, involving 573 SLE patients. The search for somatic mutations by high-throughput sequencing of 53 genes involved in clonal haematopoiesis was performed on genomic DNA collected at PLUS inclusion. CHIP prevalence was assessed in SLE and in a retrospective cohort of 479 patients free of haematological malignancy. The primary outcome was an incident CVE in SLE. RESULTS: Screening for CHIP was performed in 438 SLE patients [38 (29-47) years, 91.8% female]. Overall, 63 somatic mutations were identified in 47 patients, defining a CHIP prevalence of 10.7% in SLE. Most SLE patients (78.7%) carried a single mutation. Most variants (62.5%) were located in the DNMT3A gene. CHIP frequency was related to age and to age at SLE diagnosis, and was associated with a lower frequency of aPLs. CHIP occurred >20 years earlier (P < 0.00001) in SLE than in controls. The detection of CHIP at inclusion was not found to be associated with occurrence of CVEs during follow-up [HR = 0.42 (0.06-3.21), P = 0.406]. CONCLUSION: The prevalence of CHIP is relatively high in SLE for a given age, but was not found to be associated with incident CVEs. TRIAL REGISTRATION: ClinicalTrials.gov, https://clinicaltrials.gov, NCT05146414.

Characterisation of a high-risk profile for maternal thrombotic and severe haemorrhagic complications in pregnant women with antiphospholipid syndrome in France (GR2): a multicentre, prospective, observational study.

BACKGROUND: Prospective data about the risks of thrombotic and severe haemorrhagic complications during pregnancy and post partum are unavailable for women with antiphospholipid syndrome. We aimed to assess thrombotic and haemorrhagic events in a prospective cohort of pregnant women with antiphospholipid syndrome. METHODS: This multicentre, prospective, observational study was done at 76 centres in France. To be eligible for this study, women had to have diagnosis of antiphospholipid syndrome; have conceived before April 17, 2020; have an ongoing pregnancy that had reached 12 weeks of gestation; and be included in the study before 18 weeks of gestation. Exclusion criteria were active systemic lupus erythematosus nephropathy, or a multifetal pregnancy. Severe haemorrhage was defined as the need for red blood cell transfusion or maternal intensive care unit admission because of bleeding or invasive procedures, defined as interventional radiology or surgery, to control bleeding. The GR2 study is registered with ClinicalTrials.gov, NCT02450396. FINDINGS: Between May 26, 2014, and April 17, 2020, 168 pregnancies in 27 centres met the inclusion criteria for the study. 89 (53%) of 168 women had a history of thrombosis. The median term at inclusion was 8 weeks gestation. 16 (10%) of 168 women (95%CI 5-15) had a thrombotic (six [4%] women; 95% CI 1-8) or severe haemorrhagic event (12 [7%] women; 95% CI 4-12). There were no deaths during the study. The main risk factors for thrombotic events were lupus anticoagulant positivity at inclusion (six [100%] of six women with thrombosis vs 78 [51%] of 152 of those with no thrombosis; p=0·030) and placental insufficiency (four [67%] of six women vs 28 [17%] of 162 women; p=0·013). The main risk factors for severe haemorrhagic events were pre-existing maternal hypertension (four [33%] of 12 women vs 11 [7%] of 156 women; p=0·014), lupus anticoagulant positivity at inclusion (12 [100%] of 12 women vs 72 [49%] of 146 women; p<0·0001) and during antiphospholipid history (12 [100%] of 12 women vs 104 [67%] of 156 women; p=0·019), triple antiphospholipid antibody positivity (eight [67%] of 12 women vs 36 [24%] of 147 women; p=0·0040), placental insufficiency (five [42%] of 12 women vs 27 [17%] of 156 women; p=0·038), and preterm delivery at 34 weeks or earlier (five [45%] of 11 women vs 12 [8%] of 145 women; p=0·0030). INTERPRETATION: Despite treatment adhering to international recommendations, a proportion of women with antiphospholipid syndrome developed a thrombotic or severe haemorrhagic complication related to pregnancy, most frequently in the post-partum period. Lupus anticoagulant and placental insufficiency were risk factors for these life-threatening complications. These complications are difficult to prevent, but knowledge of the antenatal characteristics associated with them should increase awareness and help physicians manage these high-risk pregnancies. FUNDING: Lupus France, association des Sclérodermiques de France, association Gougerot Sjögren, Association Francophone contre la Polychondrite chronique atrophiante, AFM-Telethon, the French Society of Internal Medicine and Rheumatology, Cochin Hospital, the French Health Ministry, FOREUM, the Association Prix Veronique Roualet, and UCB.

Autoantibodies Targeting Ficolin-2 in Systemic Lupus Erythematosus Patients With Active Nephritis.

OBJECTIVE: Systemic lupus erythematosus (SLE) is a multisystem inflammatory disease characterized by the production of various autoantibodies. The aim of this study was to investigate the presence of anti-ficolin-2 antibodies in SLE patients and to evaluate the association between the levels of these autoantibodies, clinical manifestations, and disease activity. METHODS: This is a comparative study using a cohort of 165 SLE patients and 48 healthy subjects. SLE patients were further divided into 2 groups (low disease activity [SLE Disease Activity Index (SLEDAI) score ≤4, n = 88] and high disease activity [SLEDAI score >4, n = 77]). Clinical manifestations were defined according to the physician in charge. Active lupus nephritis (LN) was documented by kidney biopsy. Detection of anti-ficolin-2 antibodies was performed by enzyme-linked immunosorbent assay. RESULTS: Levels of anti-ficolin-2 autoantibodies were significantly higher in SLE patients as compared to healthy subjects and associated with SLEDAI score. They were found to be positive in 61 of 165 SLE patients (37%). The presence of anti-ficolin-2 antibodies was significantly related only to renal involvement, with a very high prevalence (86%) of anti-ficolin-2 antibodies in SLE patients with active LN. Patients with active proliferative LN had significantly more positive anti-ficolin-2 antibodies than those with nonproliferative LN. The combination of anti-ficolin-2, anti-ficolin-3, and anti-C1q demonstrated a very high specificity (98%) for the diagnosis of active LN. CONCLUSION: Our results support the usefulness of anti-ficolin-2 as a complementary serologic biomarker for the diagnosis of active lupus with renal manifestations.

Efficacy and Tolerance of Anti-Tumor Necrosis Factor α Agents in Cutaneous Sarcoidosis: A French Study of 46 Cases.

Importance: Evidence for the long-term efficacy and safety of anti-tumor necrosis factor α agents (anti-TNF) in treating cutaneous sarcoidosis is lacking. Objective: To determine the efficacy and safety of anti-TNF in treating cutaneous sarcoidosis in a large observational study. Design, Setting, and Participants: STAT (Sarcoidosis Treated with Anti-TNF) is a French retrospective and prospective multicenter observational database that receives data from teaching hospitals and referral centers, as well as several pneumology, dermatology, and internal medicine departments. Included patients had histologically proven sarcoidosis and received anti-TNF between January 2004 and January 2016. We extracted data for patients with skin involvement at anti-TNF initiation. Main Outcomes and Measures: Response to treatment was evaluated for skin and visceral involvement using the ePOST (extra-pulmonary Physician Organ Severity Tool) severity score (from 0 [not affected] to 6 [very severe involvement]). Epidemiological and cutaneous features at baseline, efficacy, steroid-sparing, safety, and relapses were recorded. The overall cutaneous response rate (OCRR) was defined as complete (final cutaneous ePOST score of 0 or 1) or partial response (ePOST drop ≥2 points from baseline but >1 at last follow-up). Results: Among 140 patients in the STAT database, 46 had skin involvement. The most frequent lesions were lupus pernio (n = 21 [46%]) and nodules (n = 20 [43%]). The median cutaneous severity score was 5 and/or 6 at baseline. Twenty-one patients were treated for skin involvement and 25 patients for visceral involvement. Reasons for initiating anti-TNF were failure or adverse effects of previous therapy in 42 patients (93%). Most patients received infliximab (n = 40 [87%]), with systemic steroids in 28 cases (61%) and immunosuppressants in 32 cases (69.5%). The median (range) follow-up was 45 (3-103) months. Of the 46 patients with sarcoidosis and skin involvement who were treated with anti-TNF were included, median (range) age was 50 (14-78) years, and 33 patients (72%) were women. The OCRR was 24% after 3 months, 46% after 6 months, and 79% after 12 months. Steroid sparing was significant. Treatment was discontinued because of adverse events in 11 patients (24%), and 21 infectious events occurred in 14 patients (30%). Infections were more frequent in patients treated for visceral involvement than in those treated for skin involvement (n = 12 of 25 [48%] vs n = 2 of 21 [9.5%], respectively; P = .02). The relapse rate was 44% 18 months after discontinuation of treatment. Relapses during treatment occurred in 35% of cases, mostly during anti-TNF or concomitant treatment tapering. Conclusions and Relevance: Anti-TNF agents are effective but suspensive in cutaneous sarcoidosis. The risk of infectious events must be considered.

Efficacy and safety of tumor necrosis factor antagonists in refractory sarcoidosis: A multicenter study of 132 patients.

INTRODUCTION: The off-label use of TNF antagonists in refractory sarcoidosis is increasingly reported but data on their efficacy and safety are still insufficient. OBJECTIVE: To report on efficacy and safety of TNF antagonists in severe and refractory sarcoidosis. METHODS: Examination of retrospective demographic, clinical, therapeutic, and adverse event data on 132 sarcoidosis patients (58% women; mean (min-max) age = 45.5 (14-78) years) given TNF antagonists (mainly infliximab, 91%) and investigation of response-linked factors. RESULTS: The overall clinical response (complete and partial) rate was 64%. TNF-antagonist efficacy (i.e., significant decrease of the ePOST score) was noted in cases with neurologic, heart, skin, and upper respiratory tract involvements. No significant difference in efficacy was found between anti-TNF used alone and TNF with immunosuppressant. The use of anti-TNF allowed reducing prednisone dosage at end of follow-up (p < 0.001). Adverse events were observed in 52% of the patients; they included infections (36%) and allergic reactions (8%) and required treatment interruption in 31 cases (23%). When TNF antagonists were interrupted, 13 patients experienced relapses within 14 months on average (median follow-up: 20.5 months). CONCLUSION: TNF antagonists were efficacious in about two-thirds of patients with severe/refractory sarcoidosis but their use led to a high rate of adverse events.

Potentially stress-induced acute splanchnic segmental arterial mediolysis with a favorable spontaneous outcome.

A 62-year-old woman presented with hemithoracic anesthesia and acute abdominal pain following a violent psychological stress. Magnetic resonance imaging showed a thoracic hematoma with arachnoiditis of the spinal cord. Tomography revealed a typical aspect of segmental arterial mediolysis with multiple aneurysms and stenoses of the splanchnic arteries, confirmed by abdominal arteriography. There was no argument for hereditary, traumatic, atherosclerotic, infectious, or inflammatory arterial disease. Segmental arterial mediolysis was diagnosed on the basis of the radiologic data and probably involved both medullary and splanchnic arteries. The patient spontaneously recovered and was in good health 18 months later.

Autologous hematopoietic stem cell transplantation vs intravenous pulse cyclophosphamide in diffuse cutaneous systemic sclerosis: a randomized clinical trial.

IMPORTANCE: High-dose immunosuppressive therapy and autologous hematopoietic stem cell transplantation (HSCT) have shown efficacy in systemic sclerosis in phase 1 and small phase 2 trials. OBJECTIVE: To compare efficacy and safety of HSCT vs 12 successive monthly intravenous pulses of cyclophosphamide. DESIGN, SETTING, AND PARTICIPANTS: The Autologous Stem Cell Transplantation International Scleroderma (ASTIS) trial, a phase 3, multicenter, randomized (1:1), open-label, parallel-group, clinical trial conducted in 10 countries at 29 centers with access to a European Group for Blood and Marrow Transplantation-registered transplant facility. From March 2001 to October 2009, 156 patients with early diffuse cutaneous systemic sclerosis were recruited and followed up until October 31, 2013. INTERVENTIONS: HSCT vs intravenous pulse cyclophosphamide. MAIN OUTCOMES AND MEASURES: The primary end point was event-free survival, defined as time from randomization until the occurrence of death or persistent major organ failure. RESULTS: A total of 156 patients were randomly assigned to receive HSCT (n = 79) or cyclophosphamide (n = 77). During a median follow-up of 5.8 years, 53 events occurred: 22 in the HSCT group (19 deaths and 3 irreversible organ failures) and 31 in the control group (23 deaths and 8 irreversible organ failures). During the first year, there were more events in the HSCT group (13 events [16.5%], including 8 treatment-related deaths) than in the control group (8 events [10.4%], with no treatment-related deaths). At 2 years, 14 events (17.7%) had occurred cumulatively in the HSCT group vs 14 events (18.2%) in the control group; at 4 years, 15 events (19%) had occurred cumulatively in the HSCT group vs 20 events (26%) in the control group. Time-varying hazard ratios (modeled with treatment × time interaction) for event-free survival were 0.35 (95% CI, 0.16-0.74) at 2 years and 0.34 (95% CI, 0.16-0.74) at 4 years. CONCLUSIONS AND RELEVANCE: Among patients with early diffuse cutaneous systemic sclerosis, HSCT was associated with increased treatment-related mortality in the first year after treatment. However, HCST conferred a significant long-term event-free survival benefit. TRIAL REGISTRATION: isrctn.org Identifier: ISRCTN54371254.

Autoimmune hemolytic anemia and common variable immunodeficiency: a case-control study of 18 patients.

To describe the main characteristics and treatment of autoimmune hemolytic anemia (AHA) in patients with common variable immunodeficiency (CVID), we analyzed data from 18 patients, 4 from an earlier study and 14 from the French DEF-I cohort on adult patients with primary hypogammaglobulinemia. To be included, patients had to have CVID and a previous history of AHA with a hemoglobin level < or =90 g/L at onset. To determine whether AHA is associated with a particular clinical phenotype of CVID, we conducted a case-control study from the DEF-I cohort. The estimated frequency of AHA in CVID patients from the DEF-I cohort was 5.5% (14/252). Median age at AHA diagnosis was 26 years (range, 1-57 yr), and 27.5 years (range, 5-61 yr) at CVID diagnosis. CVID was diagnosed before the onset of AHA in only 2 patients (11%). CVID was diagnosed more than 6 months after AHA in 10 cases (55.5%), and the 2 conditions were diagnosed concomitantly in 6 cases. The 14 patients included in the DEF-I cohort were compared with 238 control patients with CVID but without AHA. Corticosteroids were used as initial treatment for all patients in the current study. An initial response was obtained in 15 of 18 (83%) patients. Overall, 9 of these (60%) achieved a lasting response with steroids alone (7 patients) or in combination with intravenous immunoglobulin (2 patients). Seven patients underwent splenectomy, and 5 additional splenectomies were performed for associated autoimmune thrombocytopenic purpura. After splenectomy, a lasting response was obtained in 3 of the 7 patients with AHA. However, 5 of the 12 splenectomized patients experienced life-threatening infection. Severe infection occurred in 2 of 4 patients receiving immunosuppressive drugs. At the end of follow-up, 13 of 18 (72%) patients were in treatment-free remission (13 complete responses), and 4 of 18 (22%) were in remission while on prednisone < or =20 mg/d. One patient had died, of cancer.

Vasculitides associated with malignancies: analysis of sixty patients.

OBJECTIVE: To describe characteristics and outcomes of vasculitides associated with malignancies. METHODS: The requirement for inclusion in this retrospective, 10-year study was development of vasculitis in patients with a progressing malignancy. Malignancies secondary to immunosuppressants used to treat vasculitis were excluded. The main characteristics of vasculitides were analyzed and compared according to the type of malignancy. RESULTS: Sixty patients were included (male/female sex ratio 2.53, mean age 62.4 years). Mean followup duration was 45.2 months. Vasculitides were cutaneous leukocytoclastic (45%), polyarteritis nodosa (36.7%), Wegener's granulomatosis (6.7%), microscopic polyangiitis (5%), and Henoch-Schönlein purpura (5%). Malignancies were distributed as follows: hematologic in 63.1%, myelodysplastic syndrome (MDS) in 32.3%, lymphoid in 29.2%, and solid tumor in 36.9%. Vasculitides were diagnosed concurrently with malignancy in 38% of the cases. Manifestations of vasculitides were fever (41.7%), cutaneous involvement (78.3%), arthralgias (46.7%), peripheral neuropathy (31.7%), renal involvement (23.3%; 11.7% glomerulonephritis, 11.7% microaneurysms, 6.7% renal insufficiency), and antineutrophil cytoplasmic antibody (20.4%). Vasculitis treatments were corticosteroids (78.3%) and immunosuppressant(s) (41.7%). Vasculitis was cured in 65% of patients, but 58.3% died, with 1 death secondary to vasculitis. Independent of subtype, patients with vasculitides associated with MDS more frequently had renal manifestations (P = 0.02) and steroid dependence (P = 0.04) and achieved complete remission less often (P = 0.04) than patients with vasculitides associated with other malignancies. Patients with vasculitides associated with a solid tumor more frequently had peripheral neurologic involvement (P = 0.05). Patients with vasculitides associated with lymphoid malignancy had less frequent arthralgias (P = 0.01) and renal involvement (P = 0.02). CONCLUSION: Vasculitides occurring during malignancies present distinctive features according to the vasculitis subtype and nature of the malignancy.

Diagnostic and prognostic relevance of neuromuscular biopsy in primary Sjögren's syndrome-related neuropathy.

OBJECTIVE: To evaluate the clinicobiologic presentation in patients with primary Sjögren's syndrome (SS)-related peripheral neuropathy, the histologic results of neuromuscular biopsy (NMB), and clinical outcome, and to identify prognostic factors. METHODS: We retrospectively studied clinical and biologic presentation of 40 patients with primary SS-related neuropathy who underwent NMB. Prognostic factors of clinical outcome were assessed by univariate and multivariate analysis. RESULTS: Patients with vasculitis (lymphocytic [n = 8] or necrotizing [n = 14]) had a higher prevalence of acute-onset neuropathy, multiple mononeuropathy, sensorimotor involvement, vascular purpura, general symptoms, increased C-reactive protein level, positivity for rheumatoid factor, hypocomplementemia, and monoclonal gammopathy compared with those without vasculitis (n = 18). Comparison between patients with necrotizing or lymphocytic vasculitis did not reveal significant differences in clinical or biologic presentation except for the presence of general symptoms and rheumatoid factor. Regarding clinical evolution, the results of NMB (P < 0.0001), in particular the presence of necrotizing vasculitis (P < 0.001), an acute neuropathy onset (P < 0.0001), general symptoms (P < 0.0001), multiple mononeuropathy (P = 0.0007), presence of sensorimotor involvement (P = 0.002), and increased C-reactive protein level (P = 0.008), were significantly associated with a better outcome in univariate analysis. In multivariate analysis, NMB resulting in the identification of patients with necrotizing vasculitis was the only variable that remained significantly associated with a better outcome (P = 0.01). CONCLUSION: NMB is necessary to identify patients with necrotizing vasculitis, who have a better response to immunosuppressive therapy. NMB might therefore have both a diagnostic and prognostic relevance in primary SS-related neuropathy.

Systemic mastocytosis: predictable factors of poor prognosis present at the onset of the disease.

Systemic mastocytosis (SM) refers to a group of heterogeneous diseases that can be divided into indolent SM, for which prognosis is favorable, and malignant SM, which has a poor prognosis. While the diagnosis of SM is often a challenge since clinical and biological abnormalities are not specific, prognosis is even more difficult to predict. Thus, we aimed to highlight predictable factors in a cohort of 28 cases of SM. Among the 13 women and 15 men studied were 7 patients who had an aggressive form of SM that ultimately led to death in 3 of them. We found common characteristics among these seven patients. First, they were older when the first symptoms appeared and when the diagnosis was confirmed. Second, ascitis, lymphadenopathy, anemia, and thrombocytopenia were significantly more frequent, while cutaneous lesions and flush were less frequent. Moreover, general symptoms, gastrointestinal disorders, neutropenia, and coagulation abnormalities also seemed to characterize this group of patients. Understanding the factors that predict SM is essential in order to provide patients with the malignant form of the disease with specific treatments.

Hyper-IgM syndrome type 4 with a B lymphocyte-intrinsic selective deficiency in Ig class-switch recombination.

Hyper-IgM syndrome (HIGM) is a heterogeneous condition characterized by impaired Ig class-switch recombination (CSR). The molecular defects that have so far been associated with this syndrome - which affect the CD40 ligand in HIGM type 1 (HIGM1), CD40 in HIGM3, and activation-induced cytidine deaminase (AID) in HIGM2 - do not account for all cases. We investigated the clinical and immunological characteristics of 15 patients with an unidentified form of HIGM. Although the clinical manifestations were similar to those observed in HIGM2, these patients exhibited a slightly milder HIGM syndrome with residual IgG production. We found that B cell CSR was intrinsically impaired. However, the generation of somatic hypermutations was observed in the variable region of the Ig heavy chain gene, as in control B lymphocytes. In vitro studies showed that the molecular defect responsible for this new HIGM entity (HIGM4) occurs downstream of the AID activity, as the AID gene was induced normally and AID-induced DNA double-strand breaks in the switch micro region of the Ig heavy chain locus were detected during CSR as normal. Thus, HIGM4 is probably the consequence of a selective defect either in a CSR-specific factor of the DNA repair machinery or in survival signals delivered to switched B cells.

Neurologic presentation of Whipple disease: report of 12 cases and review of the literature.

We report 12 cases of Whipple disease in patients with prominent neurologic symptoms, along with 122 cases of Whipple disease with nervous system involvement reported in the literature. We analyzed the clinical signs and results of additional examinations in 2 groups: the first group included patients with predominantly but not exclusively neurologic signs, and the second included patients with clinically isolated neurologic presentation of the disease. Whipple disease is a multisystemic infectious disease due to Tropheryma whippelii that may present with prominent or isolated symptoms of either the central or the peripheral nervous system. Recent reports stress the importance of polymerase chain reaction (PCR) analysis of cerebrospinal fluid, magnetic resonance imaging (MRI) during follow-up, and prolonged antibiotic therapy with drugs able to cross the blood-brain barrier. Cerebrospinal fluid should be analyzed repeatedly during follow-up, and treatment should be discontinued only when the results of PCR assay performed on cerebrospinal fluid are negative. Other examinations to be done include searching for gastrointestinal tract involvement with multiple duodenal biopsies and searching for systemic involvement with lymph node biopsies, which should be analyzed with light microscopy, electron microscopy, and PCR. When all examinations are negative, if Whipple disease is suspected and a lesion is found on brain MRI, a stereotactic cerebral biopsy should be performed. Treating Whipple disease with long-term trimethoprim-sulfamethoxazole is usually effective, but the use of third-generation cephalosporins in case of incomplete response deserves further attention.