High levels of IL-10 and determination of other cytokines and chemokines in HIV-associated haemophagocytic syndrome

International Harmonization of Nomenclature and Diagnostic Criteria (INHAND): Non-proliferative and Proliferative Lesions of the Non-human Primate (M. fascicularis)

The INHAND (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions Project (www.toxpath.org/inhand.asp) is a joint initiative of the Societies of Toxicologic Pathology from Europe (ESTP), Great Britain (BSTP), Japan (JSTP) and North America (STP) to develop an internationally accepted nomenclature for proliferative and nonproliferative lesions in laboratory animals. The purpose of this publication is to provide a standardized nomenclature for classifying microscopic lesions observed in most tissues and organs from the nonhuman primate used in nonclinical safety studies. Some of the lesions are illustrated by color photomicrographs. The standardized nomenclature presented in this document is also available electronically on the internet (http://www.goreni.org/). Sources of material included histopathology databases from government, academia, and industrial laboratories throughout the world. Content includes spontaneous lesions as well as lesions induced by exposure to test materials. Relevant infectious and parasitic lesions are included as well. A widely accepted and utilized international harmonization of nomenclature for lesions in laboratory animals will provide a common language among regulatory and scientific research organizations in different countries and increase and enrich international exchanges of information among toxicologists and pathologists.

The successful treatment of haemophagocytic syndrome in patients with human immunodeficiency virus-associated multi-centric Castleman's disease

Both virus-associated haemophagocytic syndrome (HPS) and human immunodeficiency virus-associated multi-centric Castleman's disease (HIV-MCD) induced by human herpesvirus-8 (HHV-8) are extremely rare. We therefore wished to investigate their occurrence together, and establish the degree of cytokine activation present. From a prospective cohort of individuals with HIV-MCD, we investigated the incidence and outcomes of HPS and measured 15 inflammatory cytokines and the plasma HHV-8 viral loads before and during follow-up. Of 44 patients with HIV-MCD with an incidence of 4.3/10,000 patient years, four individuals (9%) were diagnosed with HPS. All are in remission (range 6-28 months) following splenectomy, etoposide and rituximab-based therapy. Plasma HHV-8 levels were raised markedly at presentation (median 3,840,000 copies/ml). Histological samples from spleen, splenic hilar lymph nodes and bone marrow demonstrated increased phagocytosis by histiocytes and presence of HHV-8-infected plasmablasts outside the follicles. Surprisingly, many known inflammatory plasma cytokines were not elevated, although interleukin (IL)-8 and interferon-gamma were increased in all cases and IL-6 levels were raised in three of four patients. HPS in the setting of HIV-MCD is common and treatment can be successful provided the diagnosis is made appropriately. Systemic activation of cytokines was limited, suggesting that immunosuppressive therapy with steroids is not indicated in HHV-8-driven HPS.

Characteristics of Activated Monocyte Phenotype Support R5-Tropic Human Immunodeficiency Virus

BACKGROUND: Microbial translocation has been recognized as an important factor in monocyte activation and contributing to AIDS pathogenesis with elevated plasma lipopolysaccharide (LPS) levels, as a marker for microbial translocation, seen in advanced HIV disease. Therefore, the current study was undertaken to assess monocyte activation in vitro by LPS and to determine its impact on monocyte phenotype. METHODS: Monocytes from non-HIV-infected donors were analyzed for CD14, CD16, CD69, TNFα, and CCR5 by flow cytometry pre- and post-stimulation with LPS. In-vitro cultures were then set up to expose non-activated and activated monocytes to R5-, X4-, and dual (R5/X4)-tropic viruses; and the amount of HIV present on the cells was assayed. RESULTS: Non-HIV-infected monocytes, after LPS stimulation, were confirmed to have an activated phenotype with increase in CD16 and CD69 surface expressions (p<0.05). The activation phenotype was supported by increase in TNFα production, p<0.05. The activated monocytes had increased surface CCR5 (from 21% to 98%; p=0.05); and were found to have more R5-tropic virus than non-activated monocytes (p<0.05). CONCLUSIONS: Following activation by LPS, non-HIV-infected monocytes were found to have increase in surface CCR5. These activated monocytes, when exposed to R5-tropic virus, were found to have more virus compared to non-activated monocytes. The significance of the findings could lie in explaining how microbial translocation plays a role in HIV progression; and possibly promoting CCR5-directed strategies in treating HIV.

Increased serum monocyte chemoattractant protein-1, macrophage inflammatory protein-1beta, and interleukin-8 concentrations in hemophagocytic lymphohistiocytosis

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is characterized by hypercytokinemia caused by macrophage and T cell activation. We analyzed the serum concentrations of monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP)-1beta, and interleukin (IL)-8 to investigate the roles of these chemokines in the pathophysiology of HLH.

METHODS

Seven patients clinically diagnosed with HLH were examined. Serum cytokines and chemokines were measured. The differences in the serum concentrations between the patients with HLH and the controls were investigated.

RESULTS

In patients with an active phase of HLH, the serum MCP-1, MIP-1beta, and IL-8 levels all were significantly higher than in healthy controls. The chemokine elevations decreased rapidly after initiation of chemotherapy. During increases in disease activity, elevation of MCP-1 and MIP-1beta preceded elevation of the serum ferritin level, which is a clinical indicator of HLH disease activity.

CONCLUSIONS

These results suggest that MCP-1, MIP-1beta, and IL-8 play important roles in the pathophysiology of HLH. In addition, the serum concentrations of these chemokines may be sensitive markers for assessing disease activity in patients with HLH.

Human herpesvirus 8-associated hemophagocytic lymphohistiocytosis in human immunodeficiency virus-infected patients

We retrospectively reviewed 5 cases of hemophagocytic lymphohistiocytosis (HL) associated with human herpesvirus 8 (HHV-8) reactivation in human immunodeficiency virus (HIV)-infected patients. All patients had clinical and biological features characteristic of HL. Pulmonary symptoms were present in all patients and were frequently life threatening. The mean number of HL episodes was 6. Four patients had HL-associated Kaposi sarcoma, and 3 had multicentric Castleman disease. The mean CD4 cell count was 200 cells/mm(3). HIV loads were stable in all patients. All patients had high levels of HHV-8 in peripheral blood mononuclear cells during attacks, and a significant increase in this parameter before the attacks was seen in 3 patients. Although 2 patients died of HL, 3 are still alive and receiving etoposide therapy (mean follow-up, 3 years). HHV-8-related HL is associated with life-threatening symptoms and biological HHV-8 reactivation, and it may be controlled in the long term by etoposide therapy combined with highly active antiretroviral therapy.