Effect of dialyzable leukocyte extract, sodium butyrate, and valproic acid in the development of anergy in murine leprosy

Background

Murine leprosy is a chronic granulomatous disease caused by Mycobacterium lepraemurium (MLM) in mice and rats. The disease evolves with the development of cellular anergy that impedes the production of interferon gamma (IFNγ), tumor necrosis factor-alpha (TNFα), and nitric oxide (NO) required to kill the microorganism. In this study we investigated whether histone deacetylase inhibitors (HDACi) (valproic acid and sodium butyrate [NaB]) and the immunomodulator transfer factor in dialyzable leukocyte extracts (DLE) can prevent anergy in murine leprosy.

Methods

Five groups of six Balb/c mice were intraperitoneally inoculated with 2 × 107 MLM. Thirty-days post inoculation, treatment was started; one group received no treatment, one was treated with rifampicin-clofazimine (R-C), one with sodium valproate (VPA), one with NaB, and one with DLE. The animals were monitored for the evidence of disease for 96 days. After euthanasia, their spleens were removed and processed for histologic, bacteriologic, and cytokine studies.

Results

R-C completely controlled the ongoing disease. DLE and NaB significantly reduced the development of lesions, including granuloma size and the number of bacilli; VPA was less effective. DLE, NaB, and VPA reverted the anergic condition in diverse grades and allowed the expression of IFNγ, TNFα, and inducible NO synthase, also in diverse grades.

Conclusion

Anergy in leprosy and murine leprosy allows disease progression. In this study, anergy was prevented, in significant degree, by DLE (an immunomodulator) and NaB (HDACi). VPA was less effective. These results suggest potential beneficial effects of DLE and NaB in the ancillary treatment of leprosy.

Sera from patients with active pulmonary tuberculosis and their household contacts induce nuclear changes in neutrophils

Background

Resident alveolar macrophages, dendritic cells, and immigrating neutrophils (NEU) are the first cells to contact Mycobacterium tuberculosis in the lung. These cells, and additional lymphoid cells in the developing granuloma, release a series of components that may concentrate in the serum and affect disease progression.

Purpose

The aim of this study was to investigate the effect of the serum from tuberculosis (TB) patients and their household contacts (HHC) on the nuclear morphology of NEU.

Materials and methods

NEU from healthy (HLT) people were incubated with sera from patients with active pulmonary TB, their HHC, and unrelated people. Changes in the nuclear morphology of NEU were analyzed by light and electron microscopy.

Results

Sera from patients with TB induced changes in the nuclear morphology of NEU that included pyknosis, swelling, apoptosis, and netosis in some cases. Sera from some HHC induced similar changes, while sera from HLT people had no significant effects. Bacteria did not appear to participate in this phenomenon because bacteremia is not a recognized feature of nonmiliary TB, and because sera from patients that induced nuclear changes maintained their effect after filtration through 0.22 µm membranes. Neither anti-mycobacterial antibodies, TNFα, IL-6, IFNγ, or IL-8 participated in the phenomenon. In contrast, soluble mycobacterial antigens were likely candidates, as small quantities of soluble M. tuberculosis antigens added to the sera of HLT people led to the induction of nuclear changes in NEU in a dose-dependent manner.

Conclusion

These results might help to detect subclinical TB within HHC, thus leading to a recommendation of prophylactic treatment.

Chronic infection with Mycobacterium lepraemurium induces alterations in the hippocampus associated with memory loss

Murine leprosy, caused by Mycobacterium lepraemurium (MLM), is a chronic disease that closely resembles human leprosy. Even though this disease does not directly involve the nervous system, we investigated a possible effect on working memory during this chronic infection in Balb/c mice. We evaluated alterations in the dorsal region of the hippocampus and measured peripheral levels of cytokines at 40, 80, and 120 days post-infection. To evaluate working memory, we used the T-maze while a morphometric analysis was conducted in the hippocampus regions CA1, CA2, CA3, and dentate gyrus (DG) to measure morphological changes. In addition, a neurochemical analysis was performed by HPLC. Our results show that, at 40 days post-infection, there was an increase in the bacillary load in the liver and spleen associated to increased levels of IL-4, working memory deterioration, and changes in hippocampal morphology, including degeneration in the four subregions analyzed. Also, we found a decrease in neurotransmitter levels at the same time of infection. Although MLM does not directly infect the nervous system, these findings suggest a possible functional link between the immune system and the central nervous system.

[Risk of contamination with blood during obstetric-gynecologic surgery]

To determine the risk of exposure to blood and body fluids potentially contaminated with infectious organisms, we instituted a prospective study of 100 gynecologic procedures performed at Hospital General Regional of Puebla, México. Accidental exposure to blood occurred during 8 procedures (8%). There were 8 glove tears (8%). Needlestick injuries occurred in 6% of the operations. The frequency of blood contamination, glove tears and percutaneous injuries is high; surgical personnel are at risk of contracting a blood-borne disease such as HIV infection or viral hepatitis. Implantation of universal blood and body fluids precautions is useful in preventing HIV exposures of which needlestick precautions are most important.