Increased red cell corpuscular volume and hepatic mitochondrial function in NRTI-treated HIV infected patients.

An increase of the mean corpuscular volume of the red blood cells has been repeatedly described in antiretroviral treated patients. Most commonly macrocytosis was associated with the use of certain nucleoside reverse transcriptase inhibitors. The aim of this study was to analyse if macrocytosis might be a marker of mitochondrial toxicity in antiretrovirally treated HIV-infected patients. Using the (13)C-methionine breath test we analysed the hepatic mitochondrial function in vivo in antiretrovirally treated HIV-infected patients with macrocytosis. MCV was significantly negatively correlated to the breath test results. For the first time we could show a significant association between an increase of the mean corpuscular erythrocyte volume by treatment with nucleoside reverse transcriptase inhibitors (NRTI) and the hepatic mitochondrial function in vivo.

The influence of HIV infection and antiretroviral therapy on the mitochondrial membrane potential of peripheral mononuclear cells.

OBJECTIVES: Clinical disorders occurring in HIV-infected patients on antiretroviral therapy (ART) have been linked to mitochondrial dysfunction, for example, lactic acidosis and lipodystrophy. Mitochondrial membrane potential (delta psi m) is the most direct measure of the state of energization of the mitochondria. We analysed delta psi m, of peripheral blood mononuclear cells (PBMCs) in HIV-negative, healthy subjects (n=8), HIV-infected, treatment-naive patients (n=30), and HIV-infected patients on ART (n=58). The influence of ART was analysed in six patients who started their first regimen. METHODS: The delta psi m of PBMC was measured by flow cytometry using the dye JC-1. RESULTS: The delta psi m was significantly lower in HIV-infected patients than in HIV-negative controls. This difference was detected in both treated (P = 0.0001) and untreated patients (P = 0.001). The delta psi m of PBMCs was highly correlated with CD4+ T-cell count in therapy-naive patients (P = 0.002, r = 0.546) and in treated patients (P = 0.028, r = 0.288). The delta psi m increased significantly in therapy-naive patients after starting ART (P = 0.001). Patients with lipoatrophy had significantly lower delta psi m than patients without lipodystrophy or with lipohypertrophy (P = 0.023). CONCLUSIONS: In HIV-infected persons delta psi m is significantly reduced. Patients with lipoatrophy have significantly reduced delta psi m. This is the first study showing that the delta psi m of PBMCs is highly correlated with CD4+ T-cell count in HIV infection.

Recurrent adrenocortical carcinoma after laparoscopic resection.

BACKGROUND: A 53-year-old man presented with left-sided flank pains to the Gastroenterology department of our clinic in September 2004. A left adrenal mass of 6.5 cm by 7.5 cm was detected by a CT scan. The patient showed no evidence of Cushing's syndrome, and had normal blood pressure and potassium levels. Endocrine tests ruled out excess levels of aldosterone or catecholamines. The patient underwent laparoscopic surgery to remove the tumor mass; histologic work-up revealed an adrenocortical carcinoma. A fluorodeoxyglucose (FDG)-PET scan 1 month, and a CT scan 8 months postoperatively showed no pathologic findings. The patient, however, again presented with left-sided flank pain to our Endocrinology department in August 2005. INVESTIGATIONS: In our department, laboratory work-up for endocrine activity was performed, as well as CT scans of the adrenal region, and FDG-PET scans in order to determine the extension of disease. Histologic work-up of the removed tumor tissue was performed. DIAGNOSIS: Recurrent adrenocortical carcinoma after laparoscopic adrenalectomy. MANAGEMENT: In our department, 10 months after initial laparoscopic surgery, local tumor recurrence was treated by repeated extensive surgery, tumor-bed radiation therapy, and mitotane treatment. A year later, a large lymph-node metastasis was surgically removed from the lower abdomen and mitotane treatment was again started postoperatively. The patient is now scheduled for polychemotherapy because of progressive metastatic disease revealed by follow-up CT and FDG-PET scanning in June 2006.

Peritumoral CpG DNA elicits a coordinated response of CD8 T cells and innate effectors to cure established tumors in a murine colon carcinoma model.

The immune system of vertebrates is able to detect bacterial DNA based on the presence of unmethylated CpG motifs. We examined the therapeutic potential of oligodeoxynucleotides with CpG motifs (CpG ODN) in a colon carcinoma model in BALB/c mice. Tumors were induced by s.c. injection of syngeneic C26 cells or Renca kidney cancer cells as a control. Injection of CpG ODN alone or in combination with irradiated tumor cells did not protect mice against subsequent tumor challenge. In contrast, weekly injections of CpG ODN into the margin of already established tumors resulted in regression of tumors and complete cure of mice. The injection site was critical, since injection of CpG ODN at distant sites was not effective. Mice with two bilateral C26 tumors rejected both tumors upon peritumoral injection of one tumor, indicating the development of a systemic immune response. The tumor specificity of the immune response was demonstrated in mice bearing a C26 tumor and a Renca tumor at the same time. Mice that rejected a tumor upon peritumoral CpG treatment remained tumor free and were protected against rechallenge with the same tumor cells, but not with the other tumor, demonstrating long term memory. Tumor-specific CD8 T cells as well as innate effector cells contributed to the antitumor activity of treatment. In conclusion, peritumoral CpG ODN monotherapy elicits a strong CD8 T cell response and innate effector mechanisms that seem to act in concert to overcome unresponsiveness of the immune system toward a growing tumor.

Combined dendritic cell- and CpG oligonucleotide-based immune therapy cures large murine tumors that resist chemotherapy.

The use of dendritic cells (DC) loaded with tumor antigen is one of the most advanced approaches in cancer immunotherapy. CpG motifs within microbial DNA detected by toll-like receptor 9 are responsible for the favorable properties of CpG oligodeoxynucleotides (ODN) as immune modulators. In this study, mature antigen-pulsed DC or peritumoral injections of CpG ODN, both effective for the treatment of small established tumors, were almost ineffective against large established tumors (1-cm diameter) in a syngeneic murine colon carcinoma model. For large tumors, the antitumor activity of mature antigen-pulsed DC was strongly increased by coinjection of CpG ODN, resulting in a transient control of tumor growth. Rejection of large tumors and long-term cure of mice was achieved by combining injection of antigen-pulsed DC plus CpG ODN at a site distant to the tumor with peritumoral injections of CpG ODN. Depletion of CD8 T cells abrogated the therapeutic activity. Large numbers of DEC-205-positive DC infiltrated the tumor in treated mice. Therapy with 5-fluorouracil and leucovorin was unable to control tumors of the same size. In conclusion, we demonstrate that the immune system, provided that appropriate stimulation with DC and CpG ODN is given, has the potential to cure animals of large solid tumors in situations where even chemotherapy is not efficient.