Hydroa vacciniforme-like lymphoproliferative disorder: an EBV disease with a low risk of systemic illness in whites.

Patients with classic hydroa vacciniforme-like lymphoproliferative disorder (HVLPD) typically have high levels of Epstein-Barr virus (EBV) DNA in T cells and/or natural killer (NK) cells in blood and skin lesions induced by sun exposure that are infiltrated with EBV-infected lymphocytes. HVLPD is very rare in the United States and Europe but more common in Asia and South America. The disease can progress to a systemic form that may result in fatal lymphoma. We report our 11-year experience with 16 HVLPD patients from the United States and England and found that whites were less likely to develop systemic EBV disease (1/10) than nonwhites (5/6). All (10/10) of the white patients were generally in good health at last follow-up, while two-thirds (4/6) of the nonwhite patients required hematopoietic stem cell transplantation. Nonwhite patients had later age of onset of HVLPD than white patients (median age, 8 vs 5 years) and higher levels of EBV DNA (median, 1 515 000 vs 250 000 copies/ml) and more often had low numbers of NK cells (83% vs 50% of patients) and T-cell clones in the blood (83% vs 30% of patients). RNA-sequencing analysis of an HVLPD skin lesion in a white patient compared with his normal skin showed increased expression of interferon-γ and chemokines that attract T cells and NK cells. Thus, white patients with HVLPD were less likely to have systemic disease with EBV and had a much better prognosis than nonwhite patients. This trial was registered at www.clinicaltrials.gov as #NCT00369421 and #NCT00032513.

Transcriptome Assessment of Erythema Migrans Skin Lesions in Patients With Early Lyme Disease Reveals Predominant Interferon Signaling.

Background: The most common clinical manifestation of early Lyme disease is the erythema migrans (EM) skin lesion that develops at the tick bite site typically between 7 and 14 days after infection with Borreliella burgdorferi. The host-pathogen interactions that occur in the skin may have a critical role in determining outcome of infection. Methods: Gene arrays were used to characterize the global transcriptional alterations in skin biopsy samples of EM lesions from untreated adult patients with Lyme disease in comparison to controls. Results: The transcriptional pattern in EM biopsies consisted of 254 differentially regulated genes (180 induced and 74 repressed) characterized by the induction of chemokines, cytokines, Toll-like receptors, antimicrobial peptides, monocytoid cell activation markers, and numerous genes annotated as interferon (IFN)-inducible. The IFN-inducible genes included 3 transcripts involved in tryptophan catabolism (IDO1, KMO, KYNU) that play a pivotal role in immune evasion by certain other microbial pathogens by driving the differentiation of regulatory T cells. Conclusions: This is the first study to globally assess the human skin transcriptional response during early Lyme disease. Borreliella burgdorferi elicits a predominant IFN signature in the EM lesion, suggesting a potential mechanism for spirochetal dissemination via IDO1-mediated localized immunosuppression.

Association of GATA2 Deficiency With Severe Primary Epstein-Barr Virus (EBV) Infection and EBV-associated Cancers.

BACKGROUND: Most patients infected with Epstein-Barr virus (EBV) are asymptomatic, have nonspecific symptoms, or have self-limiting infectious mononucleosis. EBV, however, may result in severe primary disease or cancer. METHODS: We report EBV diseases associated with GATA2 deficiency at one institution and describe the hematology, virology, and cytokine findings. RESULTS: Seven patients with GATA2 deficiency developed severe EBV disease. Three presented with EBV infectious mononucleosis requiring hospitalization, 1 had chronic active EBV disease (B-cell type), 1 had EBV-associated hydroa vacciniforme-like lymphoma with hemophagocytic lymphohistiocytosis, and 2 had EBV-positive smooth muscle tumors. Four of the 7 patients had severe warts and 3 had disseminated nontuberculous mycobacterial infections. All of the patients had low numbers of monocytes, B cells, CD4 T cells, and natural killer cells. All had elevated levels of EBV in the blood; 2 of 3 patients tested had expression of the EBV major immediate-early gene in the blood indicative of active EBV lytic infection. Mean plasma levels of tumor necrosis factor α, interferon γ, and interferon gamma-induced protein 10 were higher in patients with GATA2 deficiency than in controls. CONCLUSIONS: GATA2 is the first gene associated with EBV hydroa vacciniforme-like lymphoma. GATA2 deficiency should be considered in patients with severe primary EBV infection or EBV-associated cancer, especially in those with disseminated nontuberculous mycobacterial disease and warts.

Elevated interleukin-10: a new cause of dyslipidemia leading to severe HDL deficiency.

BACKGROUND: Low high-density lipoprotein cholesterol (HDL-C) is a risk factor for coronary artery disease. Investigating mechanisms underlying acquired severe HDL deficiency in noncritically ill patients ("disappearing HDL syndrome") could provide new insights into HDL metabolism. OBJECTIVE: To determine the cause of low HDL-C in patients with severe acquired HDL deficiency. METHODS AND RESULTS: Patients with intravascular large B-cell lymphoma (n = 2), diffuse large B-cell lymphoma (n = 1), and autoimmune lymphoproliferative syndrome (n = 1) presenting with markedly decreased HDL-C, low low-density lipoprotein cholesterol (LDL-C), and elevated triglycerides were identified. The abnormal lipoprotein profile returned to normal after therapy in all 4 patients. All patients were found to have markedly elevated serum interleukin-10 (IL-10) levels that also normalized after therapy. In a cohort of autoimmune lymphoproliferative syndrome patients (n = 93), IL-10 showed a strong inverse correlation with HDL-C (R(2) = 0.3720, P < .0001). A direct causal role for increased serum IL-10 in inducing the observed changes in lipoproteins was established in a randomized, placebo-controlled clinical trial of recombinant human IL-10 in psoriatic arthritis patients (n = 18). Within a week of initiating subcutaneous recombinant human IL-10 injections, HDL-C precipitously decreased to near-undetectable levels. LDL-C also decreased by more than 50% (P < .0001) and triglycerides increased by approximately 2-fold (P < .005). All values returned to baseline after discontinuing IL-10 therapy. CONCLUSION: Increased IL-10 causes severe HDL-C deficiency, low LDL-C, and elevated triglycerides. IL-10 is thus a potent modulator of lipoprotein levels, a potential new biomarker for B-cell disorders, and a novel cause of disappearing HDL syndrome.

Natural history of autoimmune lymphoproliferative syndrome associated with FAS gene mutations.

Autoimmune lymphoproliferative syndrome (ALPS) presents in childhood with nonmalignant lymphadenopathy and splenomegaly associated with a characteristic expansion of mature CD4 and CD8 negative or double negative T-cell receptor αß(+) T lymphocytes. Patients often present with chronic multilineage cytopenias due to autoimmune peripheral destruction and/or splenic sequestration of blood cells and have an increased risk of B-cell lymphoma. Deleterious heterozygous mutations in the FAS gene are the most common cause of this condition, which is termed ALPS-FAS. We report the natural history and pathophysiology of 150 ALPS-FAS patients and 63 healthy mutation-positive relatives evaluated in our institution over the last 2 decades. Our principal findings are that FAS mutations have a clinical penetrance of <60%, elevated serum vitamin B12 is a reliable and accurate biomarker of ALPS-FAS, and the major causes of morbidity and mortality in these patients are the overwhelming postsplenectomy sepsis and development of lymphoma. With longer follow-up, we observed a significantly greater relative risk of lymphoma than previously reported. Avoiding splenectomy while controlling hypersplenism by using corticosteroid-sparing treatments improves the outcome in ALPS-FAS patients. This trial was registered at www.clinicaltrials.gov as #NCT00001350.

IL-27 inhibits HIV-1 infection in human macrophages by down-regulating host factor SPTBN1 during monocyte to macrophage differentiation.

The susceptibility of macrophages to HIV-1 infection is modulated during monocyte differentiation. IL-27 is an anti-HIV cytokine that also modulates monocyte activation. In this study, we present new evidence that IL-27 promotes monocyte differentiation into macrophages that are nonpermissive for HIV-1 infection. Although IL-27 treatment does not affect expression of macrophage differentiation markers or macrophage biological functions, it confers HIV resistance by down-regulating spectrin ß nonerythrocyte 1 (SPTBN1), a required host factor for HIV-1 infection. IL-27 down-regulates SPTBN1 through a TAK-1-mediated MAPK signaling pathway. Knockdown of SPTBN1 strongly inhibits HIV-1 infection of macrophages; conversely, overexpression of SPTBN1 markedly increases HIV susceptibility of IL-27-treated macrophages. Moreover, we demonstrate that SPTBN1 associates with HIV-1 gag proteins. Collectively, our results underscore the ability of IL-27 to protect macrophages from HIV-1 infection by down-regulating SPTBN1, thus indicating that SPTBN1 is an important host target to reduce HIV-1 replication in one major element of the viral reservoir.

Dendritic cells from humans with hypomorphic mutations in IKBKG/NEMO have impaired mitogen-activated protein kinase activity.

The covalent attachment of lysine 63-linked polyubiquitin to the zinc-finger domain of IKBKG/NEMO (also known as IKKγ) is necessary for full activation of NF-κB. Impairments of this biochemical mechanism explain the deleterious effects of hypomorphic NEMO mutations on NF-κB signaling function in humans suffering from X-linked ectodermal dysplasia and immunodeficiency. Nevertheless, the biological function of the NEMO zinc-finger domain in the regulation of mitogen-activated protein kinase (MAPK) activity is poorly understood. Here we show that dendritic cells from patients with EDI caused by a C-terminal E391X deletion of the zinc finger of NEMO exhibit impaired MAPK activation in response to lipopolysaccharide (LPS) stimulation. Interestingly, DCs from patients with a C417R missense mutation within the zinc finger domain of NEMO in which ubiquitination of NEMO is preserved are also defective in JNK and ERK activity following LPS stimulation. Our findings indicate that the structural integrity of the NEMO ZF domain is more important than its polyubiquitination for full activation of the MAPK. Furthermore, phosphorylation and polyubiquitination of upstream TAK1 were significantly reduced in the E391X zinc-finger deleted patients, indicating that the NEMO zinc finger may play an important role in assembling the proximal signaling complex for MAPK activation.

Somatic FAS mutations are common in patients with genetically undefined autoimmune lymphoproliferative syndrome.

Autoimmune lymphoproliferative syndrome (ALPS) is characterized by childhood onset of lymphadenopathy, hepatosplenomegaly, autoimmune cytopenias, elevated numbers of double-negative T (DNT) cells, and increased risk of lymphoma. Most cases of ALPS are associated with germline mutations of the FAS gene (type Ia), whereas some cases have been noted to have a somatic mutation of FAS primarily in their DNT cells. We sought to determine the proportion of patients with somatic FAS mutations among a group of our ALPS patients with no detectable germline mutation and to further characterize them. We found more than one-third (12 of 31) of the patients tested had somatic FAS mutations, primarily involving the intracellular domain of FAS resulting in loss of normal FAS signaling. Similar to ALPS type Ia patients, the somatic ALPS patients had increased DNT cell numbers and elevated levels of serum vitamin B(12), interleukin-10, and sFAS-L. These data support testing for somatic FAS mutations in DNT cells from ALPS patients with no detectable germline mutation and a similar clinical and laboratory phenotype to that of ALPS type Ia. These findings also highlight the potential role for somatic mutations in the pathogenesis of nonmalignant and/or autoimmune hematologic conditions in adults and children.

Kinetics of serum cytokines after primary or repeat vaccination with the smallpox vaccine.

BACKGROUND: The smallpox vaccine is associated with more serious adverse events than any other live attenuated vaccine in use today. Although studies have examined serum cytokine levels in primary vaccine recipients at 1 and 3-5 weeks after vaccination with the smallpox vaccine, serial measurements have not been performed, and studies in revaccinated subjects have not been conducted. METHODS: We analyzed cytokine responses in both primary vaccine recipients and revaccinated subjects every other day for 2 weeks after vaccination. RESULTS: Primary vaccine recipients had maximal levels of granulocyte-colony-stimulating factor on days 6-7 after vaccination; peak levels of tumor necrosis factor (TNF)-alpha, soluble TNF receptor 1, interferon (IFN)-gamma, IFN-inducible protein-10 (IP-10), interleukin (IL)-6, and tissue inhibitor of metalloproteinases-1 on days 8-9 after vaccination; peak levels of soluble TNF receptor 2 and monokine induced by IFN-gamma (MIG) on days 10-11 after vaccination; and peak levels of granulocyte-macrophage-colony-stimulating factor on days 12-13 after vaccination. Primary vaccine recipients were significantly more likely to have higher peak levels of IFN-gamma, IP-10, and MIG after vaccination than were revaccinated subjects. Primary vaccine recipients were significantly more likely to have fatigue, lymphadenopathy, and headache, as well as a longer duration of these symptoms and more hours missed from work, compared with revaccinated subjects. CONCLUSIONS: The increased frequency and duration of symptoms observed in primary vaccine recipients, compared with revaccinated subjects, paralleled the increases in serum cytokine levels in these individuals. TRIAL REGISTRATION: Clinicaltrials.gov identifier NCT00325975.

Relapsing fever borreliosis in interleukin-10-deficient mice.

Relapsing fever (RF) is a spirochetal infection characterized by periods of sickness with fever at time of high bacteremia that alternate with afebrile periods of relative well being during low bacteremia. Patients with epidemic RF who are doing relatively well have extraordinarily high levels of interleukin-10 (IL-10) in the circulation. We investigated the possibility that IL-10 plays an important protective role in this infection using wild-type and IL-10-deficient mice inoculated with virulent serotype 2 of the RF spirochete Borrelia turicatae. During peak bacteremia there was increased systemic production of IL-10 that quickly resolved in the postpeak period; in contrast, IL-6 and CXCL13 production increased during the peak but remained elevated during postpeak bacteremia. IL-10 deficiency resulted in lower bacteremia, increased specific antibody production, higher production of CXCL13 and IL-6, and thrombotic and hemorrhagic complications affecting multiple organs with secondary tissue injury. Our results revealed that production of IL-10 is highly regulated during RF and plays an important protective role in the prevention of hemorrhagic and thrombotic complications at the cost of reduced pathogen control.

IL-10 helps control pathogen load during high-level bacteremia.

During relapsing fever borreliosis, a high pathogen load in the blood occurs at times of peak bacteremia. Specific IgM Abs are responsible for spirochetal clearance so in absence of B cells there is persistent high-level bacteremia. Previously, we showed that B cell-deficient mice persistently infected with Borrelia turicatae produce high levels of IL-10 and that exogenous IL-10 reduces bacteremia. This suggested that IL-10 helps reduce bacteremia at times of high pathogen load by a B cell-independent mechanism, most likely involving innate immunity. To investigate this possibility, we compared B. turicatae infection in RAG2/IL-10(-/-) and RAG2(-/-) mice. The results showed that IL-10 deficiency resulted in significantly higher bacteremia, higher TNF levels, and early mortality. Examination of the spleen and peripheral blood showed markedly increased apoptosis of immune cells in infected RAG2/IL-10(-/-) mice. Neutralization of TNF reduced apoptosis of leukocytes and splenocytes, increased production of IFN-gamma by NK cells, increased phagocytosis in the spleen, decreased spirochetemia, and rescued mice from early death. Our results indicate that at times of high pathogen load, as during peak bacteremia in relapsing fever borreliosis, IL-10 protects innate immune cells from apoptosis via inhibition of TNF resulting in improved pathogen control.

Both IL-12p70 and IL-23 are synthesized during active Crohn's disease and are down-regulated by treatment with anti-IL-12 p40 monoclonal antibody.

BACKGROUND: Interleukin (IL)-12p70 and IL-23 are key T helper-1 (TH1) cytokines that drive the inflammation seen in numerous models of intestinal inflammation. These molecules contain an identical p40 chain that is bound to a p35 chain in IL-12 and a p19 chain in IL-23, making both potentially susceptible to modulation by an anti-IL-12p40 monoclonal antibody (mAb). METHODS: In the present study, we sought to determine whether active inflammation in Crohn's disease (CD) is associated with the increased synthesis of both of these cytokines and whether patients treated with an anti-IL-12p40 mAb down-regulate IL-23 as well as IL-12p70 as previous reported. RESULTS: To this end we initially determined that IL-12p70 secretion by control and CD antigen-presenting cells (macrophages) in lamina propria mononuclear populations is optimized by stimulation with CD40L and interferon-gamma. In subsequent studies using these stimulation conditions we found that patients with CD manifested both increased IL-12p70 and IL-23 secretion before anti-IL-12p40 mAb treatment and normal levels of secretion of these cytokines following cessation of treatment. Antigen-presenting cells in lamina propria mononuclear cells from ulcerative colitis patients, in contrast, produced only baseline levels of IL-23. Finally, we found that IL-23-induced T cell production of IL-17 and IL-6 are also greatly reduced after antibody treatment. The latter data are parallel to those from previous studies showing that anti-IL-12p40 down-regulates IFN-gamma and tumor necrosis factor-alpha secretion. CONCLUSIONS: We conclude that CD but not ulcerative colitis is associated with high levels of both IL-12p70 and IL-23 secretion as well as the secretion of downstream effector cytokines, and that this cytokine production is down-regulated following administration of IL-12p40 mAb.

Anti-interleukin-12 antibody for active Crohn's disease.

BACKGROUND: Crohn's disease is associated with excess cytokine activity mediated by type 1 helper T (Th1) cells. Interleukin-12 is a key cytokine that initiates Th1-mediated inflammatory responses. METHODS: This double-blind trial evaluated the safety and efficacy of a human monoclonal antibody against interleukin-12 (anti-interleukin-12) in 79 patients with active Crohn's disease. Patients were randomly assigned to receive seven weekly subcutaneous injections of 1 mg or 3 mg of anti-interleukin-12 per kilogram of body weight or placebo, with either a four-week interval between the first and second injection (Cohort 1) or no interruption between the two injections (Cohort 2). Safety was the primary end point, and the rates of clinical response (defined by a reduction in the score for the Crohn's Disease Activity Index [CDAI] of at least 100 points) and remission (defined by a CDAI score of 150 or less) were secondary end points. RESULTS: Seven weeks of uninterrupted treatment with 3 mg of anti-interleukin-12 per kilogram resulted in higher response rates than did placebo administration (75 percent vs. 25 percent, P=0.03). At 18 weeks of follow-up, the difference in response rates was no longer significant (69 percent vs. 25 percent, P=0.08). Differences in remission rates between the group given 3 mg of anti-interleukin-12 per kilogram and the placebo group in Cohort 2 were not significant at either the end of treatment or the end of follow-up (38 percent and 0 percent, respectively, at both times; P=0.07). There were no significant differences in response rates among the groups in Cohort 1. The rates of adverse events among patients receiving anti-interleukin-12 were similar to those among patients given placebo, except for a higher rate of local reactions at injection sites in the former group. Decreases in the secretion of interleukin-12, interferon-gamma, and tumor necrosis factor alpha by mononuclear cells of the colonic lamina propria accompanied clinical improvement in patients receiving anti-interleukin-12. CONCLUSIONS: Treatment with a monoclonal antibody against interleukin-12 may induce clinical responses and remissions in patients with active Crohn's disease. This treatment is associated with decreases in Th1-mediated inflammatory cytokines at the site of disease.