Juan Carlos Garcia

Abscesses in Crohn's disease. Outcome of medical versus surgical treatment

Goals: To compare the long-term outcome of medical, percutaneous, and surgical treatment of abdominal and pelvic abscesses complicating Crohns disease. Study: All patients with Crohns disease and an abdominal abscess treated at one institution during a 10-year period were retrospectively identified. We reviewed hospital and outpatient records and contacted patients for telephone interviews. Outcome measures included abscess recurrence, subsequent surgery for Crohns disease, and medications used at the time of most recent follow-up. Results: Fifty-one subjects were identified, with a mean follow-up of 3.75 years. Fewer patients developed recurrent abscesses after initial surgical drainage and bowel resection (12%) than patients treated with medical therapy only or percutaneous drainage (56%) (p = 0.016), One half of the patients treated nonoperatively ultimately required surgery, whereas only 12% of those treated with initial surgery required reoperation during the follow-up period (p = 0.010). Most failures of nonoperative therapy occurred within 3 months. Medication use was similar between the treatment groups at the time of most recent follow-up. Conclusions: In this series, surgical management of abscesses in Crohns disease was more effective than medical treatment or percutaneous drainage for prevention of abscess recurrence. However, nonoperative therapy prevented subsequent surgery in half of the patients and may be a reasonable treatment option for some patients.

HIV Controllers with HLA-DRB1*13 and HLA-DQB1*06 Alleles Have Strong, Polyfunctional Mucosal CD4+ T-Cell Responses

ABSTRACT A small percentage of human immunodeficiency virus (HIV)-infected individuals, termed elite controllers, are able to spontaneously control HIV replication in blood. As the gastrointestinal mucosa is an important site of HIV transmission and replication as well as CD4+ T-cell depletion, it is important to understand the nature of the immune responses occurring in this compartment. Although the role of the HIV-specific CD8+ T-cell responses in mucosal tissues has been described, few studies have investigated the role of mucosal HIV-specific CD4+ T cells. In this study, we assessed HIV-specific CD4+ T-cell responses in the rectal mucosa of 28 “controllers” (viral load [VL] of <2,000 copies/ml), 14 “noncontrollers” (VL of >10,000 copies/ml), and 10 individuals on highly active antiretroviral therapy (HAART) (VL of <75 copies/ml). Controllers had higher-magnitude Gag-specific mucosal CD4+ T-cell responses than individuals on HAART (P < 0.05), as measured by their ability to produce gamma interferon (IFN-γ), interleukin-2 (IL-2), tumor necrosis factor alpha (TNF-α), and macrophage inflammatory protein 1β (MIP-1β). The frequency of polyfunctional mucosal CD4+ T cells was also higher in controllers than in noncontrollers or individuals on HAART (P < 0.05). Controllers with the strongest HIV-specific CD4+ T-cell responses possessed class II HLA alleles, HLA-DRB1*13 and/or HLA-DQB1*06, previously associated with a nonprogression phenotype. Strikingly, individuals with both HLA-DRB1*13 and HLA-DQB1*06 had highly polyfunctional mucosal CD4+ T cells compared to individuals with HLA-DQB1*06 alone or other class II alleles. The frequency of polyfunctional CD4+ T cells in rectal mucosa positively correlated with the magnitude of the mucosal CD8+ T-cell response (Spearmans r = 0.43, P = 0.005), suggesting that increased CD4+ T-cell “help” may be important in maintaining strong CD8+ T-cell responses in the gut of HIV controllers.

Multifunctional Human Immunodeficiency Virus (HIV) Gag-Specific CD8+ T-Cell Responses in Rectal Mucosa and Peripheral Blood Mononuclear Cells during Chronic HIV Type 1 Infection

ABSTRACT The intestinal tract is a lymphocyte-rich site that undergoes severe depletion of memory CD4+ T cells within days of simian immunodeficiency virus or human immunodeficiency virus type 1 (HIV-1) infection. An ensuing influx of virus-specific CD8+ T cells, which persist throughout the chronic phase of infection, has also been documented in the gastrointestinal tract. However, little is known of the functionality of these effector cells or their relationship to the disease course. In this study, we measured CD8+ T-cell responses to HIV-1 peptides in paired rectal and blood samples from chronically infected patients. In both blood and rectum, there was an immunodominant CD8+ T-cell response to HIV Gag compared to Pol and Env (P < 0.01). In contrast, cytomegalovirus pp65 peptides elicited gamma interferon (IFN-γ) secretion strongly in peripheral blood mononuclear cells (PBMC) but weakly in rectal CD8+ T cells (P = 0.015). Upon stimulation with HIV peptides, CD8+ T cells from both sites were capable of mounting complex responses including degranulation (CD107 expression) and IFN-γ and tumor necrosis factor alpha (TNF-α) production. In rectal tissue, CD107 release was frequently coupled with production of IFN-γ or TNF-α. In patients not on antiretroviral therapy, the magnitude of Gag-specific responses, as a percentage of CD8+ T cells, was greater in the rectal mucosa than in PBMC (P = 0.054); however, the breakdown of responding cells into specific functional categories was similar in both sites. These findings demonstrate that rectal CD8+ T cells are capable of robust and varied HIV-1-specific responses and therefore likely play an active role in eliminating infected cells during chronic infection.

Increased Frequency of Regulatory T Cells Accompanies Increased Immune Activation in Rectal Mucosae of HIV-Positive Noncontrollers

ABSTRACT Gut-associated lymphoid tissue (GALT) is a major site of HIV replication and CD4+ T cell depletion. Furthermore, microbial translocation facilitated by mucosal damage likely contributes to the generalized immune activation observed in HIV infection. Regulatory T cells (Treg) help maintain homeostasis and suppress harmful immune activation during infection; however, in the case of persistent viral infections such as HIV, their role is less clear. Although a number of studies have examined Treg in blood during chronic infection, few have explored Treg in the gastrointestinal mucosa. For this study, paired blood and rectal biopsy samples were obtained from 12 HIV noncontrollers (viral load of >10,000 copies/ml plasma), 10 HIV controllers (viral load of <500 copies/ml plasma for more than 5 years), and 12 HIV seronegative control subjects. Noncontrollers had significantly higher percentages of Treg in rectal mononuclear cells (RMNC), but not in blood, compared to seronegative subjects (P = 0.001) or HIV controllers (P = 0.002). Mucosal Treg positively correlated with viral load (P = 0.01) and expression of immune activation markers by CD4+ (P = 0.01) and CD8+ (P = 0.07) T cells. Suppression assays indicated that mucosal and peripheral Treg of noncontrollers and controllers maintained their capacity to suppress non-Treg proliferation to a similar extent as Treg from seronegative subjects. Together, these findings reveal that rather than experiencing depletion, mucosal Treg frequency is enhanced during chronic HIV infection and is positively correlated with viral load and immune activation. Moreover, mucosal Treg maintain their suppressive ability during chronic HIV infection, potentially contributing to diminished HIV-specific T cell responses and viral persistence.

Oral serum-derived bovine immunoglobulin improves duodenal immune reconstitution and absorption function in patients with HIV enteropathy

Objectives:To examine the impact of serum-derived bovine immunoglobulin, an oral medical food known to neutralize bacterial antigen and reduce intestinal inflammation, on restoration of mucosal immunity and gastrointestinal function in individuals with HIV enteropathy. Design:Open-label trial with intensive 8-week phase of bovine serum immunoglobulin (SBI) 2.5 g twice daily with a 4-week washout period and an optional 9-month extension study. Methods:HIV enteropathy was defined as chronic gastrointestinal symptoms including frequent loose or watery stools despite no identifiable, reversible cause. Upper endoscopy for tissue immunofluorescent antibody assay and disaccharide gut permeability/absorption studies were performed before and after 8 weeks of SBI to test mucosal immunity and gastrointestinal function. Blood was collected for markers of microbial translocation, inflammation, and collagen kinetics. A validated gastrointestinal questionnaire assessed changes in symptoms. Results:All eight participants experienced profound improvement in symptoms with reduced bowel movements/day (P = 0.008) and improvements in stool consistency (P = 0.008). Gut permeability was normal before and after the intervention, but D-xylose absorption increased in seven of eight participants. Mucosal CD4+ lymphocyte densities increased by a median of 139.5 cells/mm2 from 213 to 322 cells/mm2 (P = 0.016). Intestinal-fatty acid binding protein (I-FABP), a marker of enterocyte damage, initially rose in seven of eight participants after 8 weeks (P = 0.039), and then fell below baseline in four of five who continued receiving SBI (P = 0.12). Baseline serum I-FABP levels were negatively correlated with subsequent rise in mucosal CD4+ lymphocyte densities (r = −0.74, P = 0.046). Conclusion:SBI significantly increases intestinal mucosal CD4+ lymphocyte counts, improves duodenal function, and showed evidence of promoting intestinal repair in the setting of HIV enteropathy.

Immunodominant HIV-Specific CD8+ T-Cell Responses Are Common to Blood and Gastrointestinal Mucosa, and Gag-Specific Responses Dominate in Rectal Mucosa of HIV Controllers

ABSTRACT Previous studies have suggested that polyfunctional mucosal CD8+ T-cell responses may be a correlate of protection in HIV controllers. Mucosal T-cell breadth and/or specificity may also contribute to defining protective responses. In this study, rectal CD8+ T-cell responses to HIV Gag, Env, and Nef were mapped at the peptide level in four subject groups: elite controllers (n = 16; viral load [VL], <75 copies/ml), viremic controllers (n = 14; VL, 75 to 2,000 copies/ml), noncontrollers (n = 14; VL, >10,000 copies/ml), and antiretroviral-drug-treated subjects (n = 8; VL, <75 copies/ml). In all subject groups, immunodominant CD8+ T-cell responses were generally shared by blood and mucosa, although there were exceptions. In HIV controllers, responses to HLA-B27- and HLA-B57-restricted epitopes were common to both tissues, and their magnitude (in spot-forming cells [SFC] per million) was significantly greater than those of responses restricted by other alleles. Furthermore, peptides recognized by T cells in both blood and rectal mucosa, termed “concordant,” elicited higher median numbers of SFC than discordant responses. In magnitude as well as breadth, HIV Gag-specific responses, particularly those targeting p24 and p7, dominated in controllers. Responses in noncontrollers were more evenly distributed among epitopes in Gag, Env, and Nef. Viremic controllers showed significantly broader mucosal Gag-specific responses than other groups. Taken together, these findings demonstrate that (i) Gag-specific responses dominate in mucosal tissues of HIV controllers; (ii) there is extensive overlap between CD8+ T cells in blood and mucosal tissues, with responses to immunodominant epitopes generally shared by both sites; and (iii) mucosal T-cell response breadth alone cannot account for immune control.

Magnitude and complexity of rectal mucosa HIV-1-specific CD8+ T-cell responses during chronic infection reflect clinical status

Background The intestinal mucosa displays robust virus replication and pronounced CD4+ T-cell loss during acute human immunodeficiency virus type 1 (HIV-1) infection. The ability of HIV-specific CD8+ T-cells to modulate disease course has prompted intensive study, yet the significance of virus-specific CD8+ T-cells in mucosal sites remains unclear. Methods and Findings We evaluated five distinct effector functions of HIVgag-specific CD8+ T-cells in rectal mucosa and blood, individually and in combination, in relationship to clinical status and antiretroviral therapy (ART). In subjects not on ART, the percentage of rectal Gag-specific CD8+ T-cells capable of 3, 4 or 5 simultaneous effector functions was significantly related to blood CD4 count and inversely related to plasma viral load (PVL) (p<0.05). Polyfunctional rectal CD8+ T-cells expressed higher levels of MIP-1β and CD107a on a per cell basis than mono- or bifunctional cells. The production of TNFα, IFN-γ, and CD107a by Gag-specific rectal CD8+ T-cells each correlated inversely (p<0.05) with PVL, and MIP-1β expression revealed a similar trend. CD107a and IFN-γ production were positively related to blood CD4 count (p<0.05), with MIP-1β showing a similar trend. IL-2 production by rectal CD8+ T-cells was highly variable and generally low, and showed no relationship to viral load or blood CD4 count. Conclusions The polyfunctionality of rectal Gag-specific CD8+ T-cells appears to be related to blood CD4 count and inversely related to PVL. The extent to which these associations reflect causality remains to be determined; nevertheless, our data suggest a potentially important role for mucosal T-cells in limiting virus replication during chronic infection.

Impact of highly active antiretroviral therapy initiation on CD4(+) T-cell repopulation in duodenal and rectal mucosa.

Objective:The objective of this study was to assess the effects of HAART initiation on CD4+ T-cell repopulation and T-cell immune activation in rectal and duodenal mucosa. Design:The effects of HAART on the gastrointestinal tract remain controversial, and studies have reached different conclusions regarding its effectiveness at restoring mucosal CD4+ T cells depending upon time of initiation, duration of treatment and gastrointestinal tract region studied. Methods:We obtained blood, rectal biopsies and duodenal biopsies from 14 chronically infected individuals at baseline and at 4–9 months post-HAART initiation. We examined CD4+ T-cell frequencies in blood, rectum and duodenum at both time points, and performed a detailed assessment of CD4+ T-cell phenotype, immune activation marker expression and HIV-specific CD8+ T-cell responses in blood and rectal mucosa. Results:CD4+ T-cell percentages increased significantly in blood, rectal and duodenal mucosa after 4–9 months of HAART (P = 0.02, 0.0005, 0.0002), but remained lower than in uninfected controls. HIV-specific CD8+ T-cell responses in blood and rectal mucosa declined following HAART initiation (P = 0.0015, 0.021). CD8+ T-cell coexpression of CD38 and HLA-DR in blood and mucosa, as well as plasma sCD14, declined significantly. CD28 expression on blood and mucosal CD8+ T cells increased, whereas programmed death receptor-1 expression on blood HIV-specific CD4+ and CD8+ T cells decreased. Conclusion:Within the first months of HAART, limited CD4+ T-cell reconstitution occurs in small and large intestinal mucosa. Nevertheless, decreased immune activation and increased CD28 expression suggest rapid immunological benefits of HAART despite incomplete CD4+ T-cell reconstitution.

Drug resistance mutations in patients infected with HIV-2 living in Spain

BACKGROUND In contrast with HIV-1, information about drug resistance in HIV-2 is scarce and mainly derived from small series of patients failing antiretroviral therapy. METHODS The spectrum of changes in the reverse transcriptase (RT), protease (PR) and integrase (INT) genes was examined in HIV-2 individuals enrolled in the HIV-2 Spanish register. RESULTS From a total of 236 HIV-2-infected individuals registered in Spain from 1989 to June 2010, 53 PR, 44 RT and 8 INT sequences were obtained. Low plasma viraemia precluded collection of this information from most of the remaining cases. No major mutations associated with drug resistance in HIV-1 were recognized in 29 PR, 20 RT and 5 INT sequences from antiretroviral-naive HIV-2 individuals, although natural polymorphisms with potential effects on susceptibility to PR inhibitors were recognized at 10 positions (L10V/I, V32I, M36I, M46I, I47V, Q58E, A71V/I, G73A, V82I and L89I/V) and for nucleoside reverse transcriptase inhibitors at three positions (T69N, V75I and K219E). In 24 antiretroviral-experienced patients with virological failure the most frequent major RT resistance mutations were M184V (58%), Q151M (33%) and K65R (21%), which are rarely seen thymidine analogue mutations. In PR the most frequent major changes were V47A (17%), I54M (17%), I82F (13%), L90M (29%) and L99F (29%). Two of the three patients who failed on raltegravir had N155H in the INT region. CONCLUSIONS Drug resistance mutations in HIV-2 are selected at the same positions as in HIV-1, although with different frequency. Polymorphisms in the RT and PR associated with drug resistance in HIV-1 as compensatory changes are common in untreated HIV-2 subjects. These findings highlight the need for specific guidelines for interpreting genotypic resistance patterns in HIV-2 infection.

Infecciones por VIH-2 y HTLV-I/II en España

Hasta diciembre de 2002, se han identificado en Espana un total de 56, 566 y 109 casos de infeccion por los virus de la leucemia humana T tipos I y II (HTLV-I, HTLV-II) y de la inmunodeficiencia humana tipo 2 (VIH-2), respectivamente. La mayor parte de los sujetos infectados por VIH-2 y HTLV-I corresponden a inmigrantes procedentes de zonas endemicas, o espanoles que han viajado a aquellas regiones o que han mantenido relaciones sexuales con oriundos de ellas. Por el contrario, la infeccion por el HTLV-II predomina entre espanoles adictos a drogas por via parenteral (ADVP) que con frecuencia estan coinfectados por el VIH-1. Entre los sujetos infectados por el HTLV-I, 12 pacientes han desarrollado mielopatia subaguda y cuatro leucemia de celulas T del adulto. Tan solo 20 (18,3%) de los pacientes infectados por el VIH-2 han desarrollado sida. No se ha observado un incremento en la incidencia de la infeccion por el VIH-2 y el HTLV-I en estos anos. Por el contrario, la infeccion por el HTLV-II se ha extendido rapidamente en el colectivo de pacientes infectados por el VIH-1 adictos a drogas por via parenteral (ADVP) en prisiones con una prevalencia del 18% en determinadas carceles espanolas. No obstante, la prevalencia de dicha infeccion sigue siendo baja fuera del ambito carcelario entre los pacientes infectados por el VIH-1 ADVP (4,7%).