Severe diffuse proliferative bronchiolitis complicating culture-proven disseminated BCG infection after intravesical instillation for bladder cancer

A man in his 70s was admitted to hospital following several months of dyspnoea, night sweats, weight loss and, latterly, fevers. His symptoms correlated with a second maintenance cycle of intravesical BCG instillation for superficial bladder cancer. Blood tests showed raised C-reactive protein, alkaline phosphatase and gamma-GT, although extensive further investigations did not reveal any specific cause. Treatment for a presumed diagnosis of disseminated BCG infection was started, following which his fevers ceased. Later available results of liver biopsy taken prior to treatment supported this diagnosis, and mycobacterial blood and urine cultures grew Mycobacterium bovis Recovery was complicated by a severe diffuse proliferative bronchiolitis which responded to corticosteroids. This case highlights an important dichotomy in the pathophysiology of disseminated BCG infection. It demonstrates how morbidity can be caused by both a direct dissemination of the organism and an immune hypersensitivity response in the same patient.

In vivo effect of two first-line ART regimens on inflammatory mediators in male HIV patients

BACKGROUND

Persistent immune activation and inflammation are lying behind HIV-infection even in the setting of ART mediated viral suppression. The purpose of this study is to define the in vivo effect of two first-line ART regimens on certain inflammatory mediators in male HIV patients.

METHODS

Male, naive, HIV-infected volunteers were assigned either to tenofovir-DF/emtricitabine/efavirenz (Group_T) or abacavir/lamivudine/efavirenz (Group_A). Platelet Activating Factor (PAF) levels and metabolic enzymes together with HIV-implicated cytokines (IL-1beta, IL-6, IL-8, IL-10, IL-12p70, TNFa) and VEGF were determined for a 12-month period. Differences within each group were determined by non-parametric Friedman and Wilcoxon test, while the differences between the groups were checked by ANOVA repeated measures.

RESULTS

Both ART regimens present pronounced effect on inflammatory mediators, resulting in decreased PAF levels and Lipoprotein-associated phospholipase A2 (Lp-PLA2) activity for tenofovir-containing regimen and same as baseline PAF levels with a peak though at the 3rd month as well as elevated Lp-PLA2 activity for abacavir-containing regimen.

CONCLUSIONS

Studies regarding the effect of first-line ART regimens on inflammation may be beneficial in preventing chronic morbidities during HIV-treatment. From this point of view, the present study suggests an anti-inflammatory effect of tenofovir-containing ART, while the temporary increase of PAF levels in abacavir-containing ART may be the link between the reported cardiovascular risk and abacavir administration.

Effects of highly active antiretroviral therapy on platelet activating factor metabolism in naive HIV-infected patients: ii) study of the abacavir/lamivudine/efavirenz HAART regimen

Human Immunodeficiency Virus (HIV)-infected patients are at increased risk for cardiovascular diseases partly due to chronic inflammation. Some antiretroviral drugs and Highly Active Anti-Retroviral Therapy (HAART) regimens seem to be related and amplify this increased risk, especially the ones containing abacavir. Platelet-Activating-Factor (PAF) is a potent inflammatory mediator that is implicated in both cardiovascular diseases and HIV-related manifestations. Our objective is to study the in vivo effect of the abacavir/lamivudine/efavirenz first-line HAART regimen on PAF metabolism in HIV-infected patients. The specific activities of PAF basic biosynthetic enzymes in leukocytes and platelets, PAF-cholinephosphotransferase (PAF-CPT) and lyso-PAF-acetyltransferase (Lyso-PAF-AT), but also those of PAF-basic catabolic enzymes, PAF acetylhydrolase (PAF-AH) in leukocytes and platelets and Lipoprotein-associated-Phospholipase-A2 (LpPLA2) in plasma, were measured in blood samples of 10 asymptomatic naïve male HIV-infected patients just before and after 1, 3 and 6 months of treatment. CD4 cell counts, viral load and several biochemical markers were also measured in the same blood samples of these patients. The repeated ANOVA measures and the Pearson r criterion were used for studying statistical differences and correlations - partial correlations respectively. Even though viral load was decreased and CD4 cell counts were beneficially increased after treatment with the abacavir/lamivudine/efavirenz regimen, the main enzyme of the remodelling PAF-synthesis that is implicated in pro-atherogenic inflammatory procedures, Lyso-PAF-AT activity, was increased at 3 months of treatment in both leukocytes and platelets, while the main enzyme of PAF-degradation, PAF-AH, was increased as a response only in leukocytes at the 3rd month. Although the abacavir/lamivudine/efavirenz HAART regimen exhibits very efficient antiretroviral activities, on the other hand it induces an in vivo transient increase in the inflammation-related remodeling PAF-biosynthetic pathway. This finding supports the hypothesis of inflammation-mediated increased cardiovascular risk in HIV-infected patients during the first months of abacavir-containing HAART.

In vitro anti-inflammatory and anti-coagulant effects of antibiotics towards Platelet Activating Factor and thrombin

BACKGROUND

Sepsis is characterized as a systemic inflammatory response that results from the inability of the immune system to limit bacterial spread during an ongoing infection. In this condition the significant mediator of inflammation Platelet Activating Factor (PAF) and the coagulant factor thrombin are implicated. In animal models, treatment with PAF-antagonists or co-administration of antibiotics with recombinant-PAF-Acetylhydrolase (rPAF-AH) have exhibited promising results. In order to examine the putative anti-inflammatory and/or antithrombotic interactions between antibiotic treatment used in sepsis with PAF and/or thrombin, we studied the in vitro effects of these compounds towards PAF or/and thrombin related activities and towards PAF basic metabolic enzymes.

METHODS

We assessed the inhibitory effect of these drugs against PAF or thrombin induced aggregation on washed rabbit platelets (WRPs) or rabbit Platelet Reach Plasma (rPRP) by evaluating their IC50 values. We also studied their effect on Cholinephosphotransferase of PAF (PAF-CPT)/Lyso-PAF-Acetyltransferase (Lyso-PAF-AT) of rabbit leukocytes (RLs), as well as on rabbit plasma-PAF-AH, the key enzymes of both de novo/remodelling PAF biosynthesis and PAF degradation, respectively.

RESULTS

Several antibiotics inhibited PAF-induced platelet aggregation of both WRPs and rPRP in a concentration-depended manner, with clarithromycin, azithromycin and amikacin exhibiting the higher inhibitory effect, while when combined they synergistically inhibited PAF. Higher concentrations of all antibiotics tested were needed in order to inhibit PAF induced aggregation of rPRP, but also to inhibit thrombin induced aggregation of WRPs. Concentrations of these drugs similar to their IC50 values against PAF activity in WRPs, inhibited also in vitro PAF-CPT and Lyso-PAF-AT activities of rabbit leukocytes, while only clarithromycin and azithromycin increased rabbit plasma-PAF-AH activity.

CONCLUSIONS

These newly found properties of antibiotics used in sepsis suggest that apart from their general actions, these drugs may present additional beneficial anti-inflammatory and anti-coagulant effects against the onset and establishment of sepsis by inhibiting the PAF/PAF-receptor and/or the thrombin/protease-activated-receptor-1 systems, and/or by reducing PAF-levels through both PAF-biosynthesis inhibition and PAF-catabolism induction. These promising in vitro results need to be further studied and confirmed by in vivo tests, in order to optimize the efficacy of antibiotic treatment in sepsis.

In Vivo Effects of a Ginkgo Biloba Extract on Platelet Activating Factor Metabolism in Two Asymptomatic Hiv-Infected Patients

Ginkgo biloba products seem to protect from several pathological conditions, including HIV manifestations, where Platelet Activating Factor (PAF) is implicated. In the present study, we examined for the first time the in vivo effects of a standardized formulation of Ginkgo biloba extract (150 mg daily, per os) on PAF metabolism in blood cells and plasma of two male, asymptomatic HIV-infected patients, not receiving antiretroviral treatment, during a 9-month period. These patients differed at baseline in terms of duration of HIV infection, viral load levels, CD4 cell counts and Highly Active Antiretroviral Therapy (HAART) experience. In the first patient with early HIV infection, after an initial transient increase, a return of both plasma viral load and PAF biosynthetic enzyme activities in leukocytes to their baseline levels was observed during Ginkgo biloba use. As a result PAF degradation also remained low in this patient. The second patient with late but not advanced HIV infection, had higher levels of viral load and a lower CD4 cell count at baseline. The use of 150 mg of a Ginkgo biloba extract was probably insufficient to induce PAF degradation and/or to suppress the induction of PAF biosynthesis observed. At the same time, the initial high levels of viral load were further increased and CD4 cell counts were finally decreased during the study. The observed differences in PAF metabolism during Ginkgo use seem to be related to the initial heterogeneity of these patients. It appears that in some HIV-infected patients inhibition of the PAF/PAF-receptor system, along with a decrease/down-regulation of PAF-biosynthesis, illustrates a new potential role for Ginkgo biloba compounds in the treatment of HIV infection and its manifestations. However, more tests on a larger number of patients are needed in order to support these preliminary observations.

Anti-platelet-activating factor effects of highly active antiretroviral therapy (HAART): a new insight in the drug therapy of HIV infection?

Platelet-activating factor (PAF) is a potent inflammatory mediator, which seems to play a role in the pathogenesis of several AIDS manifestations such as AIDS dementia complex, Kaposi's sarcoma, and HIV-related nephropathy. PAF antagonists have been studied in these conditions with promising results. In order to examine the possible interactions between PAF and antiretroviral therapy, we studied the effect of nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors, and protease inhibitors against PAF biological activities and its basic biosynthetic enzymes dithiothreitol-insensitive PAF-cholinephosphotransferase (PAF-CPT) and lyso-PAF-acetyltransferase (Lyso-PAF-AT), as well as its main degradative enzyme PAF-acetylhydrolase, of human mesangial cell line (HMC). We also studied the effect of several backbones and highly active antiretroviral therapy (HAART) regimens against PAF activity. Among the drugs tested, several inhibited PAF-induced platelet aggregation in a concentration-depended manner, with tenofovir, efavirenz, and ritonavir exhibiting the higher inhibitory effect. In addition, when these drugs were combined in backbones and HAART regimens based on American antiretroviral therapy proposals, they also synergistically exhibited an inhibitory effect against PAF-induced platelet aggregation. Several of these drugs have also inhibited in vitro microsomal PAF-CPT activity, and concentrations of lopinavir-r or tenofovir-DF (similar to their IC(50) against PAF-induced platelet aggregation) exhibited the same effect against PAF-CPT and Lyso-PAF-AT when added in the cell medium of cultured HMC. In addition, in naïve patients treated with one of the most potent anti-PAF HAART regimens (efavirenz/emtricitabine/tenofovir-DF) for a period of 1 month, a significant reduction of the specific activity of PAF-CPT of washed human leukocytes of these patients was also observed, compared with its levels before the HAART treatment. These promising results need to be further studied and confirmed by additional in vivo tests in order to optimize HAART efficacy.

Looking beyond highly active antiretroviral therapy: drug-related hepatotoxicity in patients with human immunodeficiency virus infection

Management of human immunodeficiency virus (HIV) has become increasingly complex since the introduction of highly active antiretroviral therapy (HAART). Patients with HIV have become exposed to an increasing array of drugs to treat HIV, prevent opportunistic infections and immune dysfunction, and manage comorbid illnesses and therapeutic complications. Hepatic complications have become common and may lead to discontinuation of treatment and significant morbidity. Up to 90% of patients with acquired immunodeficiency syndrome (AIDS) receive at least one drug that can cause hepatotoxicity. Clinicians treating patients with HIV frequently face difficulty distinguishing abnormal liver transaminase levels and toxicities in patients receiving several drugs. Some potential causes of hepatic dysfunction are viral infections, alcohol and substance abuse, and hepatotoxic drugs such as HAART. Recent reports have focused on the hepatotoxicity of HAART and the role of hepatitis viruses to the exclusion of many other agents prescribed for patients with HIV. Many of the common antibiotics, antifungals, antivirals, and ancillary agents prescribed for patients with HIV are independently associated with hepatotoxicity. Clinicians should be aware of the potential non-antiretroviral hepatotoxic agents that are frequently administered in HIV management.

Hepatitis C virus and human immunodeficiency virus co-infection in women

Women account for almost one of four newly diagnosed cases of the human immunodeficiency virus (HIV) infection in the United States. It is believed that up to 20% of them are co-infected with hepatitis C virus (HCV). AIDS is now the third leading cause of death in women aged 25 to 44 years in the United States. The ability to better control the HIV infection and improve survival among the co-infected population will make managing chronic liver disease due to hepatitis C the next clinical challenge for these women. This article reviews the available data and summarizes the primary care approach to the female patient with HCV-HIV co-infection.