Lung abscess in adults: clinical comparison of immunocompromised to non-immunocompromised patients.

Information related to the clinical characteristics and isolated microbes associated with lung abscesses comparing immunocompromised (IC) to non-immunocompromised (non-IC) patients is limited. A retrospective review for 1984-1996 identified 34 consecutive adult cases of lung abscess (representing 0.2% of all cases of pneumonia), including 10 non-IC and 24 IC patients. Comparison of age, gender, tobacco use, pre-existing pulmonary disease or recognized aspiration risk factors were not significantly different between the two groups. Upper lobe involvement accounted for the majority of cases, although multi-lobe involvement was limited to IC patients. There were no differences in the need for surgical intervention, and mortality was very low for both groups. Anaerobes were the most frequent isolates for non-IC patients (30%), whereas aerobes were the most frequent isolate for IC patients (63%). Importantly, certain organisms were exclusively isolated in the IC group and multiple isolates were obtained only from the IC patients.Thus, comparing non-IC to IC patients, clinical characteristics may be similar whereas important differences may exist in the microbiology associated with lung abscess. These findings have important implications for the clinical management of these patient groups, and support a strategy to aggressively identify microbial agents in abscess material.

IL-1beta induces eotaxin gene transcription in A549 airway epithelial cells through NF-kappaB.

Eotaxin is an asthma-related C-C chemokine that is produced in response to interleukin-1beta (IL-1beta). We detected an increase in newly transcribed eotaxin mRNA in IL-1beta-stimulated airway epithelial cells. Transient transfection assays using promoter-reporter constructs identified a region as essential for IL-1beta-induced increases in eotaxin transcription. Using site-directed mutagenesis, we found that a nuclear factor-kappaB (NF-kappaB) site located 46 bp upstream from the transcriptional start site was both necessary and sufficient for IL-1beta induction of reporter construct activity. Electrophoretic mobility shift assay demonstrated that IL-1beta-stimulated airway epithelial cells produced p50 and p65 protein that bound this site in a sequence-specific manner. The functional importance of the NF-kappaB site was demonstrated by coexpression experiments in which increasing doses of p65 expression vector were directly associated with reporter activity exclusively in constructs with an intact NF-kappaB site (r(2) = 0.97, P = 0.002). Moreover, IL-1beta-induced increases in eotaxin mRNA expression are inhibited by inhibitors of NF-kappaB. Our findings implicate NF-kappaB and its binding sequence in IL-1beta-induced transcriptional activation of the eotaxin gene.

Management and outcome patterns for adult Pneumocystis carinii pneumonia, 1985 to 1995: comparison of HIV-associated cases to other immunocompromised states.

STUDY OBJECTIVES: Encompassing periods preceding and following major advances in the diagnosis and management of HIV-related Pneumocystis carinii pneumonia (PCP), the purpose of this study was to determine whether management and outcome patterns of non-HIV PCP parallel the management and outcomes of AIDS-related PCP. DESIGN: Retrospective review of medical records. SETTING: A 375-bed tertiary-care urban teaching hospital and referral center. PATIENTS: All adult patients with morphologically confirmed PCP from 1985 to 1995. MEASUREMENTS AND RESULTS: From 1985 to 1995, 638 confirmed cases of PCP were identified, including 605 cases in 442 HIV-positive persons (HIV + PCP), and 33 cases in 33 non-HIV patients (non-HIV PCP). For HIV + PCP cases, a peak of 104 cases occurred in 1987, with a gradual decline to 23 in 1995. The proportion of cases requiring hospitalization declined from a peak of 91.6% in 1987 to a low of 51.6% in 1992. ICU admission was required for 6.3 to 8.2%, and mechanical ventilation for 4.7 to 5.7%. Overall mortality improved from 11.7 to 6.6%, although mortality for intubated patients remained at 50 to 60%. For the non-HIV PCP cases, 97% occurred from 1989 to 1995 with similar annual frequency, 97% required hospitalization, 69% required ICU admission, and 66% required intubation. Overall mortality was 39%, and mortality for intubated patients was 59%. CONCLUSIONS: Despite major advances in diagnosis and management, PCP remains a significant problem in non-HIV-infected patients, and respiratory failure remains associated with a high mortality rate for patients with both HIV + PCP and non-HIV PCP.

Peripheral blood CD4 + T-lymphocyte counts during Pneumocystis carinii pneumonia in immunocompromised patients without HIV infection.

STUDY OBJECTIVES: To assess the potential use of peripheral blood CD4 + T-lymphocyte counts (CD4 + counts) as a clinically useful biological marker to identify specific immunocompromised patients (without HIV infection) at high risk for Pneumocystis carinii pneumonia (PCP). DESIGN: Prospective observational study. SETTING: Three hundred seventy-five-bed tertiary-care urban referral teaching hospital, and 250-bed community-based referral hospital. PATIENTS: One hundred seventy-one consecutive confirmed HIV-seronegative hospitalized and ambulatory adults, including 22 patients with active PCP, 8 patients with bacterial pneumonia, 24 persons in two groups considered at high clinical risk, 38 persons in two groups considered at low or undefined risk, and 79 persons in four groups considered not at risk for PCP (including healthy individuals). MEASUREMENTS AND RESULTS: Compared to counts in healthy individuals, median CD4 + counts were significantly decreased in patients with active PCP (61 cells/microL vs 832 cells/microL; p = 0.001) where 91% of patients had a CD4 + count < 300 cells/microL at the time of PCP diagnosis. Median CD4 + counts were also reduced in the high clinical risk groups of recent organ transplant recipients (117 cells/microL; p = 0.007), 64% with < 300 cells/microL, and patients receiving chemotherapy (221 cells/microL; p<0.01), 80% with < 300 cells/microL. For the low or undefined clinical risk groups, the median CD4 + counts were not significantly reduced, although 39 to 46% of individuals receiving long-term corticosteroid therapy (alone or in combination with other agents) had CD4 + counts < 300 cells/microL. Median CD4 + counts in individuals considered not at risk for PCP were similar to those in healthy subjects. Compared to counts in patients with active PCP, median CD4 + counts were significantly higher in bacterial pneumonia patients (486 cells/microL; p<0.05), but similar to those in healthy subjects. CONCLUSIONS: These data suggest that for immunosuppressed persons without HIV infection (especially in low or undefined PCP risk groups), CD4 + counts may be a useful clinical marker to identify specific individuals at particularly high clinical risk for PCP and may help to guide chemoprophylaxis.

Safety of bedside percutaneous dilatational tracheostomy in obese patients in the ICU.

STUDY OBJECTIVE: To examine the safety of bedside percutaneous dilatational tracheostomy in obese patients. DESIGN: Case series of consecutive obese patients (body mass index > or = 27 kg/m(2)) with acute respiratory failure in a medical, cardiac, or surgical ICU unit who required tracheostomy for failure to wean and continued mechanical ventilatory support. RESULTS: Thirteen obese patients were identified and consented to the procedure. Bedside percutaneous dilatational tracheostomy was successfully performed in the ICU for all 13 patients. Procedural complications were limited to paratracheal tracheostomy tube placement in one patient, with immediate identification and appropriate correction. Postprocedural complications were limited to a cuff leak in one patient. CONCLUSION: Bedside percutaneous tracheostomy can be safely performed in obese patients.

Insulin antibodies and hypoglycemia in diabetic patients. Can a quantitative analysis of antibody binding predict the risk of hypoglycemia?

We report a noninsulin-dependent diabetes mellitus (NIDDM) patient with spontaneous, severe hypoglycemic reactions and the presence of insulin antibodies. He had a remote antecedent history of beef-pork insulin therapy as well as exposure to hydralazine. Detailed insulin binding kinetic studies were performed in this patient as well as in six other insulin-treated diabetic patients with anti-insulin antibodies (three with and three without an obvious cause of hypoglycemia). Sera from the current patient and five of the six other diabetic patients (one NIDDM, four IDDM) revealed two types of binding sites: high-affinity with low capacity (Kd, 0.4-12.4 x 10(-9) mol/L; binding capacity, 0.6-659 mU/L) and low-affinity with high capacity (Kd, 0.3 to 35.7 x 10(-7) mol/L; binding capacity; 202-113,680 mU/L). One NIDDM patient had only high-affinity antibodies (Kd, 22.9 x 10(-9) mol/L; binding capacity of 78 mU/L). Type of diabetes mellitus, insulin antibody titers or their binding capacities, insulin levels (total, bound, or free), and bioavailable insulin were not related to hypoglycemic reactions. Two calculated values by the method described tended to discriminate patients with and without hypoglycemia. The calculated amount of low-affinity antibody bound insulin ranged from 69.4-2090 mU/L vs < 4-70.6 mU/L in patients with and without hypoglycemia, respectively. The best discrimination was afford by the percent saturation of low-affinity binding sites; values were clearly higher in the patients with hypoglycemia (2.5-34.4%) than in those without hypoglycemia (not detectable, 0.06, 0.15%). Consideration of the possible drug-associated insulin antibody formation in insulin-treated diabetics and the novel quantitative analysis of the antibody binding kinetics should prove helpful in evaluating patients with high insulin antibody titers and assessing the risk of hypoglycemia.

Differences in hepatitis B markers between clinical and preclinical health care personnel.

Hepatitis B virus (HBV) infection is an occupational risk for health care personnel (HCP). Vaccination is an important preventive measure but high cost of vaccination limits the feasibility of giving vaccine to all HCP. To find an optimum approach for vaccination we conducted a study on HCP in Maulana Azad Medical College and associated LNJPN hospital. A total of 162 subjects were screened. Eight were excluded because of prior vaccination against HBV. Two groups of subjects were selected namely preclinical and clinical. The preclinical group comprised first year medical students and the clinical group comprised of HCP who have been exposed to clinical departments. The subjects were screened for HBsAg, anti HBs and anti HBc viral markers. 86 subjects were screened in the preclinical group. Two (2.3%) were positive for HBsAG; 16 (18%) and 9 (10.4%) were positive for anti HBs and anti HBc respectively. In the clinical group a total of 68 subjects were screened. Amongst them 1.4% were positive for HBsAg; 47 (69%) and 38 (55%) were positive for anti HBs and anti HBc respectively. The study revealed that there was a significant difference in the titre of the viral markers in the preclinical group as compared to the clinical group. Seventy (82%) of preclinical subjects were at high risk for the infection as they moved into clinical departments. Few subjects will be excluded from the vaccination schedule based on anti HBs screening and hence screening prior to vaccination is not cost effective. However in the clinical group 69% will be excluded from the vaccination schedule based on anti HBs positivity and screening will save up to 60% of cost involved in vaccination.