The lungs of patients with acquired immunodeficiency syndrome (AIDS) are frequently affected by opportunistic and nonopportunistic infections and pulmonary localizations of Kaposi's sarcoma. The aim of this study was to verify whether, in patients with human immunodeficiency virus (HIV) infections, immunologic pulmonary abnormalities set the stage for the lung complications. For this purpose, a phenotypic and functional characterization of lymphocytes recovered from the bronchoalveolar lavage (BAL) fluid of 24 patients with clinical symptoms and signs of HIV infections was performed (six patients with constitutional disease, five patients with neurologic manifestations, and 13 patients with full-blown AIDS). Our data showed that (1) in patients with HIV, the percentage and absolute number of pulmonary CD8 cells were significantly increased over those in control subjects (in 25% of these patients, mostly with full-blown AIDS, CD8 cells sustained an alveolitis); (2) lung CD4 cells were reduced in percentage but not in absolute number, with the exception of patients with AIDS in whom a significant decrease of the absolute number of BAL CD4 cells has been found (further phenotypic analysis of CD4 lymphocytes showed a reduction of the expression of T4A, B, and E with respect to the T4, T4C, T4D, and T4F epitopes); (3) although the number of BAL cells bearing NK-related determinants was increased, we were unable to demonstrate any in vitro natural killer cell activity. We suggest that the impairment of a proper NK activity in the lungs of these patients might be central to the mechanisms leading to the in situ immunodeficiency state and to the pulmonary complications characterizing AIDS.
IntroductionHaemolysis is the leading cause of sample rejection in laboratory haemostasis. Most studies focused on artificially haemolysed samples. The aim of this study was a prospective assessment of spontaneous haemolysis on haemostasis tests, by comparing results of haemolysed (H) versus new, non-haemolysed (NH) specimens, collected within 4hrs. As new coagulometers can identify interfering substances, visual assessment of haemolysis was also compared with instrumental haemolysis index and stratified in subclasses.Materials and methodsTwo hundred and sixty nine paired samples were collected and analysed using ACL TOP750-CTS (Instrumentation Laboratory, Bedford, USA), for prothrombin time (PT), activated partial thromboplastin time (aPTT), D-Dimer (DD), fibrinogen (Fib) and antithrombin (AT). Bias between H and NH was calculated and compared with the respective critical difference (CD).ResultsMean bias was - 0.1 s for PT (P = 0.057), - 1.1 s for aPTT (P < 0.001), 1025 ng/mL for DD (P < 0.001), - 0.04 g/L for Fib (P = 0.258) and 1.4% for AT (P = 0.013). Bias exceeding the CD varied according to the method, with larger differences for aPTT (36.1%) and DD (17.1%) and < 8% for PT, Fib and AT. No correlation emerged between free haemoglobin values and difference in haemostasis tests in H and NH samples for any tests. Moderate/severe haemolysis involved > 95% of samples. The agreement between visual assessment and instrumental evaluation of haemolysis was 0.62.ConclusionSpurious haemolysis deeply influences aPTT and DD, and to a lesser extent AT and Fib. Prothrombin time seems only slightly influenced, suggesting that PT can be accepted also in haemolysed samples. Although a good inter-observer correlation of haemolysis evaluation was found, the instrumental assessment of haemolysis seems recommendable.
To characterize the cytotoxic events taking place in the lung of patients with HIV-1 infection, we studied the cells recovered from the bronchoalveolar lavage (BAL) of nine patients with AIDS, seven patients with AIDS-related complex, and two patients with lymphadenopathy. Phenotypic analysis was coupled to a series of functional evaluations of nonspecific cytotoxic abilities performed on lung effectors, including their property to bind K-562 targets, to release natural killer cytotoxic factor (NKCF), and to become cytotoxic following in vitro activation with rIL-2. Our results demonstrated that lung cells bearing the NK-related CD16, CD56, and CD57 antigens were quantitatively increased, irrespective of the disease stage. The majority of the cells also coexpressed the CD3 molecule and the alpha/beta T cell receptor (TCR), notably the phenotype characterizing MHC-unrestricted cytotoxic T cells. From a functional point of view, a severe impairment of the spontaneous cytotoxic ability was demonstrated in most patients. Evaluation at the single cell level showed a normal percentage of the effector/target conjugates formed by HIV-1 lymphocytes. The release of NKCF was undetectable in patients with AIDS even following lectin stimulation, whereas BAL cells from patients with earlier infection produced and/or could be triggered to release discrete amounts of NKCF by incubation with PHA. Studies designed to activate lung cytotoxic cells with rIL-2 showed that in most patients the stimulation of effector cells with rIL-2 enhanced the spontaneous killing and elicited a lymphokine-activated killer (LAK) phenomenon.(ABSTRACT TRUNCATED AT 250 WORDS)
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