Impact of 5 years of maximally successful highly active antiretroviral therapy on CD4 cell count and HIV-1 DNA level

OBJECTIVES: To evaluate the impact on CD4 cell count and HIV-1 DNA level in peripheral blood mononuclear cells (PBMC) of long-term highly active antiretroviral therapy (HAART) in the setting of maximal success, i.e., constant plasma HIV-1 RNA load suppression. DESIGN: Retrospective analysis of patients selected for a constantly undetectable plasma HIV-1 RNA load since HAART initiation. METHODS: HIV-1 DNA was measured in PBMC using a real-time polymerase chain reaction assay. Loess estimates and regression analysis were used for modelling the variations of the CD4 cell count and HIV DNA level over time. RESULTS: The study included 41 patients chronically infected with HIV-1 who had been taking HAART for a median duration of 60.4 months and had an undetectable plasma HIV RNA load ever since the first 6 months of HAART; 25 were tested for HIV-1 DNA. The mean CD4 cell count increase was high during the first 18 months on therapy (168 x 10 cells/l per year), much lower afterwards (38 x 10 cells/l per year), independently of the baseline CD4 cell count. Most of the patients (73.2%) reached a CD4 cell count constantly > or = 400 x 10/l during follow-up. HIV-1 DNA showed a mean decrease of 0.48 log10 copies/10 PBMC during the first year, of 0.18 log10 copies/10 PBMC per year during the 2nd and 3rd years, but no significant decrease afterwards. CONCLUSIONS: These results question the benefit of very long-term maintenance of HAART in terms of CD4 gain and HIV-1 DNA reduction.     

HIV type 1-infected dendritic cells induce apoptotic death in infected and uninfected primary CD4 T lymphocytes

In addition to their essential role in adaptive immunity, dendritic cells (DCs) participate in innate immunity. In the context of measles virus (MV) or cytomegalovirus infections, they develop cytotoxic functions that may contribute in vivo to the elimination of virus-infected cells, but that also kill infected and noninfected T lymphocytes. Because the human immunodeficiency virus (HIV) induces T cell depletion through mechanisms that are still obscure, we investigated its ability to trigger DC cytotoxicity. When incubated with HIV, monocyte-derived DCs induced apoptosis in MDA-231 cells, which are sensitive to MV-induced DC cytotoxicity, and in uninfected as well as HIV-infected H9 CD4+ T cell lines. This apoptosis was inhibited by a mixture of FasL, TRAIL, TNF-alpha, and TWEAK inhibitors. Indeed, HIV infection induced or enhanced sensitivity to TRAIL, TNF-alpha, and TWEAK in H9 cells. Moreover, dendritic cells incubated with HIV-1 BAL or a wildtype HIV-1 isolate induced apoptosis in autologous primary CD4+ T lymphocytes, infected or not with a wild-type HIV-1 isolate. Therefore, induction of DC cytotoxicity by HIV may be relevant to in vivo HIV infection. Induction of cytotoxicity in DCs by HIV might contribute to HIV-associated T cell depletion through induction of apoptosis, especially in the early stages of infection. It may also contribute to elimination of infected cells in vivo, thereby enhancing cross-presentation of HIV by DCs. Therefore this new cytotoxic function of DCs may play an important role in innate and adaptive immunity during HIV infection.     

Comparison of advanced therapy medicinal product gingiva and skin substitutes and their in vitro wound healing potentials

Skin and oral mucosa substitutes are a therapeutic option for closing hard‐to‐heal skin and oral wounds. Our aim was to develop bi‐layered skin and gingiva substitutes, from 3 mm diameter biopsies, cultured under identical conditions, which are compliant with current European regulations for advanced therapy medicinal products. We present in vitro mode of action methods to (i) determine viability: epithelial expansion, proliferation (Ki‐67), metabolic activity (MTT assay); (ii) characterize skin and gingiva substitutes: histology and immunohistochemistry; and (iii) determine potency: soluble wound healing mediator release (enzyme‐linked immunosorbent assay). Both skin and gingiva substitutes consist of metabolically active autologous reconstructed differentiated epithelium expanding from the original biopsy sheet on a fibroblast populated connective tissue matrix (donor dermis). Gingival epithelium expanded 1.7‐fold more than skin epithelium during the 3 week culture period. The percentage of proliferating Ki‐67‐positive cells located in the basal layer of the gingiva substitute was >1.5‐fold higher than in the skin substitute. Keratins 16 and 17, which are upregulated during normal wound healing, were expressed in both the skin and gingiva substitutes. Notably, the gingiva substitute secreted higher amounts of key cytokines involved in mitogenesis, motogenesis and chemotaxis (interleukin‐6 > 23‐fold, CXCL8 > 2.5‐fold) as well as higher amounts of the anti‐fibrotic growth factor, hepatocyte growth factor (>7‐fold), compared with the skin substitute. In conclusion, while addressing the viability, characterization and potency of the tissue substitutes, important intrinsic differences between skin and gingiva were discovered that may explain in part the superior quality of wound healing observed in the oral mucosa compared with skin.     

Chronic Q Fever Diagnosis—Consensus Guideline versus Expert Opinion

Chronic Q fever, caused by Coxiella burnetii, has high mortality and morbidity rates if left untreated. Controversy about the diagnosis of this complex disease has emerged recently. We applied the guideline from the Dutch Q Fever Consensus Group and a set of diagnostic criteria proposed by Didier Raoult to all 284 chronic Q fever patients included in the Dutch National Chronic Q Fever Database during 2006–2012. Of the patients who had proven cases of chronic Q fever by the Dutch guideline, 46 (30.5%) would not have received a diagnosis by the alternative criteria designed by Raoult, and 14 (4.9%) would have been considered to have possible chronic Q fever. Six patients with proven chronic Q fever died of related causes. Until results from future studies are available, by which current guidelines can be modified, we believe that the Dutch literature-based consensus guideline is more sensitive and easier to use in clinical practice.     

Replication analysis confirms the association of ARID5B with childhood B-cell acute lymphoblastic leukemia

Although childhood acute lymphoblastic leukemia is the most common pediatric cancer, its etiology remains poorly understood. In an attempt to replicate the findings of 2 recent genome-wide association studies in a French-Canadian cohort, we confirmed the association of 5 SNPs [rs7073837 (P=4.2 × 10⁻⁴), rs10994982 (P=3.8 × 10⁻⁴), rs10740055 (P=1.6 × 10⁻⁵), rs10821936 (P=1.7 × 10⁻⁷) and rs7089424 (P=3.6 × 10⁻⁷)] in the ARID5B gene with childhood acute lymphoblastic leukemia. We also confirmed a selective effect for B-cell acute lymphoblastic leukemia with hyperdiploidy and report a putative gender-specific effect of ARID5B SNPs on acute lymphoblastic leukemia risk in males. This study provides a strong rationale for more detailed analysis to identify the causal variants at this locus and to better understand the overall functional contribution of ARID5B to childhood acute lymphoblastic leukemia susceptibility.     

Antioxidant and anti-inflammatory effects of mild hypothermia in the attenuation of liver injury due to azoxymethane toxicity in the mouse

Previous studies have demonstrated protective effects of mild hypothermia following acetaminophen (APAP)-induced acute liver failure (ALF). However, effects of this treatment in ALF due to other toxins have not yet been fully investigated. In the present study, the effects of mild hypothermia in relation to liver pathology, hepatic and cerebral glutathione, plasma ammonia concentrations, progression of encephalopathy, cerebral edema, and plasma proinflammatory cytokines were assessed in mice with ALF resulting from azoxymethane (AOM) hepatotoxicity, a well characterized model of toxic liver injury. Male C57BL/6 mice were treated with AOM (100 μg/g; i.p.) or saline and sacrificed at coma stages of encephalopathy in parallel with AOM mice maintained mildly hypothermic (35°C). AOM treatment led to hepatic damage, significant increase in plasma transaminase activity, decreased hepatic glutathione levels, and brain GSH/GSSG ratios as well as selective increases in expression of plasma proinflammatory cytokines. Mild hypothermia resulted in reduced hepatic damage, improvement in neurological function, normalization of glutathione levels, and selective attenuation in expression of circulating proinflammatory cytokines. These findings demonstrate that the beneficial effects of mild hypothermia in experimental AOM-induced ALF involve both antioxidant and anti-inflammatory mechanisms.     

Cryptogenic organizing pneumonia after rituximab therapy for presumed post-kidney transplant lymphoproliferative disease

Cryptogenic organizing pneumonia (COP, formerly bronchiolitis obliterans organizing pneumonia) is rare in children. We describe an 11-year-old girl with Epstein–Barr virus (EBV) reactivation/presumed post-transplant lymphoproliferative disease (PTLD) 15 months after undergoing a deceased donor kidney transplantation. Treatment with reduced immunosuppression, ganciclovir, and cytomegalovirus immunoglobulin was complicated by severe graft rejection, prompting therapy with methylprednisolone, anti-thymocyte globulin and four weekly doses of rituximab (total 1500 mg/m²). Tacrolimus- and prednisone-based anti-rejection prophylaxis was complemented with low-dose sirolimus. When the lactate dehydrogenase and uric acid levels rose 10 weeks after the first rituximab infusion and bilateral pulmonary nodules were detected by computerized tomography, recurrence of PTLD was suspected. Open lung biopsy of the clinically asymptomatic patient identified the nodules as COP, characterized by abundant CD3⁺ T-cells, few B-cells, and the absence of EBV, cytomegalovirus, or adenovirus antigens. With normalization of the peripheral B-cell count, EB viremia reappeared and persisted, despite minimal immunosuppression. Four years later, the patient was diagnosed with classical Hodgkin lymphoma-type PTLD with multiple pulmonary and abdominal nodes. This first report of rituximab-associated, pediatric COP highlights the risk of pulmonary complications after treatment with B-cell depleting agents in solid organ transplant recipients, and the importance of a histopathologic diagnosis and vigilant follow-up of such lesions.     

Vitamin D insufficiency: implications for the immune system

Chronic kidney disease (CKD) is characterized by a loss of kidney function and dysregulation of vitamin D metabolism. Well known are the defects in final activation of vitamin D to 1,25-dihydroxyvitamin D₃ [1,25(OH)₂D₃], resulting in renal osteodystrophy. However, in recent years, 1,25(OH)₂D₃ has been identified as having effects far beyond calcium and bone metabolism. In this review, specific attention is given to the effects of 1,25(OH)₂D₃ on the immune system and the implications of vitamin D deficiency, a feature of many patients with CKD, on immune function.