[Secreted phospholipases A2 (sPLA2): friends or foes? Are they actors in antibacterial and anti-HIV resistance?]. / Fosfolipasas A2 segregadas (sPLA2): amigas o enemigas? Actores de la resistencia antibacteriana y antivirus de la inmunodeficiencia humana?

In this paper the authors update on the deletereous or beneficial roles of human and animal secretory phospholipases A2 (sPLA2). Although human sPLA2-IIA (inflammatory) was initially thought as a foe because its pathogenic implication in sepsis, multiorganic failure or other related syndromes, recent data indicates its role in in the antiinfectious host resistance. Thus, sPLA2-IIA exhibits potent bactericidal activities against gram-negative and gram-positive (in this case, together with other endogenous inflammatory factors) bacteria. Surprisingly, human sPLA-IIA does not show in vitro anti-human immunodeficiency virus (HIV) activity, whilst several sPLA2-IA isolated from bee and serpent venons do it: this is the case for crotoxin, a sPLA2-IA isolated from the venon of Crotalus durissus terrificus (sPLA2-Cdt). The mechanism for the in vitro anti-HIV activity of sPLA2-Cdt (inhibition of Gag p24) appears to be related to the ability of the drug to desestabilize ancorage (heparans) and fusion (cholesterol) receptors on HIV target cells.

AM3 (Inmunoferón) as an adjuvant to hepatitis B vaccination in hemodialysis patients.

BACKGROUND: Patients with end-stage renal disease (ESRD) undergoing hemodialysis have severe alterations in cell-mediated immunity (CMI) that increases their risk of contracting chronic hepatitis B virus (HBV) infection and decreases their protective responses to HBV vaccine. In an effort to improve the humoral response to an accelerated HBV vaccine protocol in these patients, the ability of an immunomodulator, AM3, to improve seroconversion was investigated. METHODS: A total of 269 patients were enrolled in a multicenter trial. All patients received a DNA recombinant vaccine (40 microg HBsAg/dose/day) on days 0, 10, 21, and 90. AM3 or placebo (3 g/day) was given orally for 30 consecutive days beginning 15 days prior to the first vaccine dose. Anti-HBsAg titers were measured on days 120 and 270 after the beginning of the trial. RESULTS: After one month, 207 patients could be evaluated and 132 patients after six months. The placebo and AM3-treated groups had comparable seroconversion and protective response rates one month after the final vaccine dose. The AM3 treatment group, but not the placebo group, maintained these protective titers up to six months after the final vaccine dose. At this time, the percentage of high responders (anti-HBsAg>100 IU/L) and mean anti-HBsAg titers in the AM3 group was significantly higher than in the placebo group. CONCLUSIONS: AM3 is a safe and easily tolerated oral agent that potentiates long-term serological immunity to hepatitis B in hemodialysis patients after vaccination.

Prognostic significance of tumor infiltrating natural killer cells subset CD57 in patients with squamous cell lung cancer.

Natural killer (NK) cells have been implied in the resistance against certain tumors and virally-infected cells. The prognostic significance of tumor infiltrating NK cells in primary squamous cell lung carcinoma (SqCLC) has not been fully studied. Fifty patients with primary SqCLC were evaluated for the presence of tumor infiltrating natural killer cells subset CD57 (TINK) after surgery. None of them received adjuvant therapy. Immunohistochemical studies of surgery pieces were performed by using the monoclonal antibody CD57. The number of TINK cells was counted by using a MICRON image analyzer. The total area studied for each tumor was of 1 cm(2). In this area, 50 intratumoral fields of 0.173 mm(2) were selected. The reference value used was the median (five TINK cells/field) of all tumors analyzed. After a minimum follow-up of 2 years the Kaplan-Meier method was used to obtain survival curves. Multivariate analysis were performed by using the Cox regression model. The survival was significantly better in patients with more than five TINK cells/field (Logrank P=0.0317). According to TNM classification, in those patients screened as stage IB (37 patients) the differences in survival were significantly higher (Logrank P=0.0016). In the multivariate analysis including TNM (surgical-pathologic stage), age, and endoscopy localization, the risk of death in patients with less than five TINK cells/field was 2.50 fold higher (CI 95%; range 1.07-5.85) than in those patients with more than five TINK cells/field. These results show that TINK cells appear to be a prognostic factor in the survival of patients with SqCLC. The possible antitumoral role of these cells in SqCLC is discussed.