Osteonecrosis of the femoral head in people living with HIV: anatomopathological description and p24 antigen test

Objective

To examine the presence of HIV in bone tissue of people living with HIV (PLWHIV) with osteonecrosis of femoral head and describe clinical and anatomopathological findings.

Design

This is a case series which included 44 PLWHIV with osteonecrosis of femoral head who underwent total hip arthroplasty.

Methods

Clinical data were obtained through analysis of the patients’ medical records. Bone tissue obtained during total hip arthroplasty was retrieved and sent for conventional and immunohistochemical analysis. Monoclonal antibodies were used to mark the p24 (HIV), CD31 (vascular endothelial cells), CD68 (macrophages), and D₂40 (cells of the lymphatic endothelium) antigens.

Results

Dyslipidemia was found in 48% of the patients and lipodystrophy in 31%. Histological analysis showed similar characteristics for the entire sample. Degeneration of joint cartilage was visualized with the presence of fissures and fibrillations, as well as subchondral sclerosis and necrosis of the subchondral cancellous bone tissue. Lymphoplasmocytic inflammatory reaction was observed, with the presence of macrophages containing a foamy, vacuolated cytoplasm, as well as the presence of ceroid pigment and occasional granulation tissue. The reaction with the monoclonal anti-p24 antibody was negative in the samples from all 44 PLWHIV undergoing hip arthroplasty. Reactions with the anti-CD31 and anti-D₂40 antibodies were negative. Staining with CD68 antibody confirmed that the cells visualized with foamy, vacuolated cytoplasm were macrophages.

Conclusion

p24 HIV antigen was not detected in the bone tissue of PLWHIV and osteonecrosis. The most frequent anatomopathological findings were extensive necrosis of bone tissue, large vacuoles filled with fat cells, inflammatory lymphoplasmocytic reaction with macrophages containing vacuolated cytoplasm, and the presence of ceroid pigment.

Paradoxical effects of vitamin C in Chagas disease

Trypanosoma cruzi infection stimulates inflammatory mediators which cause oxidative stress, and the use of antioxidants can minimize the sequelae of Chagas disease. In order to evaluate the efficacy of vitamin C in minimizing oxidative damage in Chagas disease, we orally administered ascorbic acid to Swiss mice infected with 5.0 × 10⁴ trypomastigote forms of T. cruzi QM2 strain. These animals were treated for 60 days to investigate the acute phase and 180 days for the chronic phase. During the acute phase, the animals in the infected and treated groups demonstrated lower parasitemia and inflammatory processes were seen in more mice in these groups, probably due to the higher concentration of nitric oxide, which led to the formation of peroxynitrite. The decrease in reduced glutathione concentration in this group showed a circulating oxidant state, and this antioxidant was used to regenerate vitamin C. During the chronic phase, the animals in the infected and treated group showed a decrease in ferric reducing ability of plasma and uric acid concentrations as well as mobilization of bilirubin (which had higher plasma concentration), demonstrating cooperation between endogenous non-enzymatic antioxidants to combat increased oxidative stress. However, lower ferrous oxidation in xylenol orange concentrations was found in the infected and treated group, suggesting that vitamin C provided biological protection by clearing the peroxynitrite, attenuating the chronic inflammatory process in the tissues and favoring greater survival in these animals. Complex interactions were observed between the antioxidant systems of the host and parasite, with paradoxical actions of vitamin C.

Fibrosis Progression in Paired Liver Biopsies from HIV/HCV-Coinfected Patients without Prior Treatment of Hepatitis C

Several studies have demonstrated that HIV/hepatitis C virus (HCV)-coinfected patients experience more rapid fibrosis progression. In this study, to estimate the annual rate of direct liver fibrosis progression, we used analyses of paired biopsy samples from HIV/HCV-coinfected patients without prior treatment of hepatitis and assessed the possible association of fibrosis progression with certain clinical variables. We evaluated 30 HIV/HCV-coinfected patients, with no history of prior treatment of hepatitis C, who underwent paired liver biopsies. All patients were under antiretroviral therapy at first and second biopsies. The average annual progression rate was 0.13 fibrosis unit/year, with 36.7% of patients defined as progressors. Liver fibrosis progression was associated with alanine aminotransferase (ALT; P < .001) and aspartate aminotransferase (AST; P < .0340) levels over 3 times the upper limit of normal present at first biopsy. Elevated ALT and AST levels appear to be associated with more accelerated liver fibrosis progression among HIV/HCV-coinfected patients.

Respiratory syncytial virus (RSV) pneumonia in a southern muriqui (Brachyteles arachnoides)

BACKGROUND

An adult male Brachyteles arachanoides, kept in captivity since 1990, was found dead without apparent clinical evidence.

METHODS

Necropsy report, histopathology, immunohistochemistry, and ultrastructural examination were conducted.

RESULTS

Pulmonary syncytial cells were positive for respiratory syncytial virus (RSV), and ultrastructural examination revealed viral particles inside macrophages compatible with the Paramyxoviridae family.

CONCLUSIONS

Muriquis are susceptible to RSV pneumonia followed by respiratory distress syndrome and death.

Leptospirosis pulmonary haemorrhage syndrome is associated with linear deposition of immunoglobulin and complement on the alveolar surface

Leptospirosis is a zoonotic infection associated with severe diseases such as leptospirosis pulmonary haemorrhage syndrome (LPHS). The cause of pulmonary haemorrhage is unclear. Understanding which mechanisms and processes are involved in LPHS will be important in treatment regimens under development for this life-threatening syndrome. In the present study, we evaluated 30 lung specimens from LPHS patients and seven controls using histology and immunohistochemistry (detection of IgM, IgG, IgA and C3) in order to describe the pathological features associated with this syndrome. Immunoglobulin deposits were detected on the alveolar surface in 18/30 LPHS patients. Three staining patterns were observed for the immunoglobulins and C3 in the lung tissues of LPHS patients: AS, delicate linear staining adjacent to the alveolar surface, which was indicative of a membrane covering the luminal surface of type I and II pneumocyte cells; S, heterogeneous staining which was sporadically distributed along the alveolar septum; and IA, weak, focal intra-alveolar granular staining. Human LPHS is associated with individual and unique histological patterns that differ from those of other causes of pulmonary haemorrhage. In the present study, it was found that the linear deposition of immunoglobulins (IgA, IgG and IgM) and complement on the alveolar surface may play a role in the pathogenesis of pulmonary haemorrhage in human leptospirosis.

CHARACTERIZATION OF CELLULAR PHENOTYPES AND CYTOKINE EXPRESSION IN BALT FROM CHILDREN WITH CONGENITAL HEART DISEASES

The present study was performed to target and call attention to the bronchial associated lymphoid tissue (BALT), part of our immune system, from which, we believe, several forms of prophylactic and therapeutic approaches can be developed. The characterization of its immune components, cells, and cytokines, in absence of antigenic stimuli, is pioneer in literature. Eighteen cases of necropsies were chosen and selected the paraffin-embedded lungs. The ages of 11 females and 7 males varied from 5 to 31 months. Cause of death: congenital heart diseases.

EXCLUSION CRITERIA

lung infection at necropsy and/or arterial hypertrophy greater than Heath-Edwards' 1st degree. Immunohistochemical technique was applied to identify the cell phenotypes and the cytokines in situ. BALT was identified in all cases in this study. The main cellular phenotypes in BALT were T helper (TH) and B lymphocytes surrounded by T cytotoxic lymphocytes, natural killer cells, and dendritic cells in less quantities. Interleukin 10 and Tumor Necrosis Factor alpha were the predominant cytokines in BALT without antigenic stimuli. BALT is an important structure of the lung immune system in infants, with a tendency to maintain an environment favorable to the Th2 arm of immune response. It needs more exploration to define its behavior in front of infections, especially those with pulmonary tropism.

A quantitative and morphometric study of mast cells in cutaneous leishmaniasis

Background Mast cells (MCs) are related with healing process in chronic inflammatory diseases, although in cutaneous leishmaniasis (CL) its importance is unknown. The aim of this study was to determine the correlation of MC with clinical findings in patients with the localized form of CL. Methods A cohort of 85 patients with CL was evaluated. MCs count was performed in pre-treatment biopsies and correlation with clinical findings and Leishmania species determined by PCR were performed. Results The MCs count in patients with CL caused by Leishmania (V.) braziliensis was 14.3 +/- 9.8 cells/mm(2), and 7.0 +/- 6.5 cells/mm(2) in patients with L. (L.) amazonensis (P < 0.05). The linear regression of MCs count with the age showed a tendency of cell number decreasing, according to ageing of the patient (r2 = 0.05; P < 0.05). The association of disease's duration and MCs count was positive (r2 = 0.11; P < 0.05). There was not any association of MCs count with number of lesions neither with Leishmania antigen expression. The MCs count was higher in patients with earlier healing after treatment (P < 0.05). Conclusion MC can be important in CL and related with healing lesion.

Histopathology of mast cells and cytokines during healing of human mucosal leishmaniasis

Mast cells (MCs) are associated with chronic inflammatory diseases. However, there is no study evaluating the importance of MCs in the mucosal leishmaniasis (ML). The aim of this study was to quantify the most important cytokines associated with mucosal leishmaniasis, before and after disease treatment, correlating with the healing. A cohort of 12 patients with ML was evaluated, and biopsies were taken before and after the treatment. A quantitative estimation of MCs and some cytokines was analysed by density of the labelled cells through immunohistochemistry. The MCs count in the tissue from patients with ML before treatment showed a mean of 29.3 +/- 37.9 cells/mm(2). The MCs count in patients with ML after healing decreased to 14.8 +/- 23.9 cells/mm(2). There was an inverse relation of MCs with IFN-gamma and IL-4 expression (r2 = 29.4 and r2 = 22.3 with P < 0.05). The expression of IL-10 and TNF-alpha was not related with MCs count. MCs decrease after treatment associated with decrease of IL-4 and IFN-gamma. The explanations of cytokine correlation are discussed in the article.

The effects of human herpesvirus 8 infection and interferon-gamma response in cutaneous lesions of Kaposi sarcoma differ among human immunodeficiency virus-infected and uninfected individuals

BACKGROUND

Kaposi sarcoma (KS) is associated with human herpesvirus 8 (HHV-8). The cutaneous immune response in this tumour is not well established and a better understanding is necessary.

OBJECTIVES

To evaluate the HHV-8 expression and immune response in cutaneous lesions of classic KS (CKS) and AIDS-associated KS (AIDS-KS).

METHODS

We performed a quantitative immunohistochemical study of cells expressing HHV-8 latency-associated nuclear antigen (LANA), CD4, CD8 and interferon (IFN)-gamma in skin lesions from patients with CKS and AIDS-KS (with or without highly active antiretroviral therapy, HAART).

RESULTS

CKS showed higher LANA expression compared with AIDS-KS, regardless of HAART. We also found higher LANA expression in nodules compared with patch/plaque lesions. The tissue CD4+ cell proportion was lower in AIDS-KS patients without HAART than in patients with CKS. In CKS lesions, CD4+ and CD8+ cells expressed IFN-gamma, as shown by double immunostaining. AIDS-KS presented low numbers of IFN-gamma-expressing cells. CD8+ cell numbers were similar in all groups, which appeared unrelated to the clinical or epidemiological type of KS.

CONCLUSIONS

Our quantitative data on the pattern of KS lesions in selected groups of patients, as shown by in situ immune response, demonstrated a CD4+ T-cell involvement associated with IFN-gamma, an environment of immune response-modified human immunodeficiency virus (HIV) infection. In our sample, the promotion of KS in patients without HIV appears to be related to higher HHV-8 load or virulence than in those with AIDS. This higher resistance may be explained by a sustained immune response against this herpesvirus, that is only partially restored but effective after HAART.

Hantavirus infection induces a typical myocarditis that may be responsible for myocardial depression and shock in hantavirus pulmonary syndrome

Despite clinical evidence of myocardial dysfunction, there is no pathological evidence of myocardial injury in hantavirus pulmonary syndrome (HPS). The dominant opinion is that the primary cardiac lesion is functional rather than structural. The present study describes hantaviral antigen and particles in the cardiac endothelium and interstitial macrophages in association with a typical myocarditis in HPS. Human hearts from 14 individuals who died of HPS were compared with hearts from 14 individuals who died of acute necrotizing pancreatitis associated with acute lung injury and 4 individuals who died accidental deaths without thoracic injury (as controls); all cases were selected from autopsies. Transmural blocks of myocardial tissue were excised from the middle portion of the left-ventricular free wall and fixed in formalin. Small samples of myocardial tissue from 4 HPS cases and 4 non-HPS controls were fixed in glutaraldehyde for electron microscopic study. Histomorphometric, immunohistochemical, and ultrastructural methods were employed to detect the presence of hantavirus in the myocardium and to evaluate interstitial edema and the minor diameter of myocytes, to characterize the immunophenotype, and to estimate the number of inflammatory cells and in situ cytokine-producing cells and the T helper cell subset 1 and 2 immune responses (tumor necrosis factor [TNF]-alpha, interferon-gamma, interleukin [IL]-10, and IL-4). Cardiac remodeling; hantaviral antigen and particles in the endothelium and macrophages; scattered foci of myofiber necrosis; greater interstitial cellular infiltration, mainly composed of macrophages and memory T lymphocytes and a significant number of T helper and B lymphocytes; and TNF-alpha protein expression in macrophage-type cells and cardiomyocytes were observed to a greater extent in HPS myocardium than in normal and acute pancreatitis control myocardium. These findings give support to the opinion that structural changes could be responsible for myocardial depression and shock in HPS, and it should be properly named as "hantavirus cardiopulmonary syndrome" (HCPS).

Immunopathology of the duodenal mucosa of HIV-positive patients during combined antiretroviral therapy

The objective of the present study was to evaluate the duodenal mucosa of HIV-infected patients during antiretroviral therapy. This was an observational study conducted on HIV-positive patients and a control group. Group 1 comprised 22 HIV-negative individuals while 38 HIV-positive individuals were classified according to the CDC 1993 classification into group 2 (A1 or A2) or group 3 (B2, A3, B3, C2, C3). All subjects were submitted to upper gastrointestinal endoscopy with duodenal biopsies. Qualitative, semi-quantitative and quantitative histological analyses were performed. Results were considered significant when P < 0.05. A higher prevalence of inflammatory infiltrate and eosinophilia was observed in the HIV group, together with a reduction in mucosal CD4+ lymphocyte (L) counts [median (lower-upper quartiles), 12.82 (8.30-20.33), 6.36 (1.75-11.66) and 1.75 (0.87-3.14) in groups 1, 2 and 3, respectively] which was not correlated with disease stage. The extent of CD4+L count reduction was similar in blood and duodenal mucosa. Normal CD8+L and CD45RO+L counts, and normal numbers of macrophages and antigen-presenting cells were also found in the HIV patients. The cytokine pattern did not differ among groups. Tissue HIV, assessed by p24 antigen, correlated with a higher CD45RO+L count (77.0 (61-79.8) and 43.6 (31.7-62.8) in p24+ and p24-, respectively, P = 0.003), and IL-4 positivity (100 and 48.2% in p24+ and p24-, respectively, P = 0.005). The duodenal mucosa of HIV+ patients showed a relatively preserved histological architecture. This finding may be characteristic of a population without opportunistic infections and treated with potent antiretroviral therapy, with a better preservation of the immune status.

Short report: persistence of tumor necrosis factor-alpha in situ after lesion healing in mucosal leishmaniasis

Mucosal leishmaniasis (ML) is a disease characterized by intense activation of inflammatory cells and extensive tissue destruction. Among the cytokines involved in the immune response to ML, tumor necrosis factor-alpha (TNF-alpha) has attracted strong interest because of its roles in the modulation of the immune response. We studied 20 patients with ML who provided biopsy specimens before treatment and after lesion healing obtained by specific therapy. The biopsy specimens were subjected to immunohistochemical analysis for in situ quantification of cellular and extracellular TNF-alpha. The amount of TNF-alpha was significantly lower in the healed lesions compared with pretreatment biopsy specimens, although TNF-alpha persisted at the tissue level even after lesion healing. This relevant finding demonstrates for the first time an in situ tissue reduction of TNF-alpha after treatment and shows persistence of TNF-alpha in healed lesions may be related to the maintenance of an immunopathologic background for relapses observed in ML.