An immunological evaluation of type II diabetic patients with periodontal disease.

Peridontal disease is a frequent complication of diabetes, and diabetic subjects often exhibit decreased immune response with increased susceptibility to infection. We evaluated the possible relationship between immune response and periodontal disease in 40 type II diabetic patients, mean (+/- SD) age 59 +/- 8 years and mean disease duration 17 +/- 4 years, with good metabolic control (mean fasting plasma glucose, 10.5 +/- 3.8 mM/L, mean HbA1c 8.1 +/- 1.66%), and in 40 age and gender-matched controls. Interproximal alveolar bone loss (ABL), as the percentage of bone loss from the cement enamel junction (CEJ) to the apex, was measured with a modified Schei ruler at the deepest point on the mesial/distal surface of the teeth, except third molars, on a panoramic radiograph. Immunological evaluation involved study of NADPH neutrophil superoxide production, neutrophil chemotaxis, lymphocyte subpopulations, immunoglobulins and complement. Diabetic patients showed significant differences compared with controls regarding ABL (30.6 +/- 14.7% versus 17.6 +/- 4.3%; p < 0.0001) and the T-helper/T-suppressor ratio (2.3 +/- 1.0% versus 1.8 +/- 0.8%; p < 0.05). Other parameters of cell-mediated immunity and humoral immune response did not show any significant variations. No correlation between immunological and radiographic analysis parameters were found. Further studies are needed to verify the exact role played by immunological factors in type II diabetic patients with periodontal disease.

The TEST 1 automated system: a new method for measuring the erythrocyte sedimentation rate.

We evaluated performance of the TEST 1 (SIRE Analytical Systems, Udine, Italy), a fully automated analyzer for the measurement of the erythrocyte sedimentation rate (ESR). Intra-assay reproducibility was satisfactory for a wide range of ESR values, whereas there was a significant decrease in ESR data when the samples were stored at 4 degrees C for up to 24 hours. We compared TEST 1 with the Westergren ESR method approved by the International Council for Standardization in Haematology (ICSH) and with the Diesse Ves-Matic analyzer Linear regression analysis comparing the TEST 1 and the ICSH reference method yielded satisfactory correlations for K3 EDTA- and sodium citrate-anticoagulated samples. Bland-Altman analysis showed no evidence of a systematic bias between the TEST 1 and the reference method. A close correlation was found between the TEST 1 system and the Diesse Ves-Matic analyzer despite a significant positive systematic bias. Reference values for men and women were analyzed according to nonparametric statistics. The TEST 1 was easy to use, had a satisfactory operative practicability required minimal maintenance, and reduced contact with potential biohazards. This system enables the determination of ESR with any common standard-sized tube; the use of samples anticoagulated with K3 EDTA can widely reduce the workload in clinical laboratories.

Complete analytical and diagnostic performances of the Abbott Cell Dyn 3500.

METHODS: The study reports the analytical and diagnostic performances of Cell Dyn 3500 (Abbott), an automated haematology analyser that provides the electrical impedance and the optical detection of total leukocyte and a five population leukocyte differential count. The evaluation of complete blood count and differential leukocyte count parameters was performed following the guidelines of the International Council for Standardization in Haematology and those of the National Committee for Clinical Laboratory Standards document H20-A. RESULTS: The CD 3500 demonstrated a good linearity, minimal carry-over, as well as acceptable levels of within and between-batch imprecision and stability. An excellent correlation between CD 3500 and the routine systems used in our laboratory (Technicon H*2 and Coulter STKS) was found for the major haematological indices, though agreement was not as good for MCHC. There was a good correlation between CD 3500 and manual reference differential method for neutrophils, lymphocytes, eosinophils and basophils, with the exception of monocytes. CONCLUSIONS: Regarding clinical sensitivity, the CD 3500 showed a high specificity to detect morphological abnormalities, but low sensitivity especially for the identification of immature granulocytes and nucleated red blood cells; if we overall evaluate any qualitative flags, we found an appreciable increase in sensitivity.

Phagocytic activity of bronchoalveolar lavage neutrophils in intensive care unit patients on mechanical ventilation.

In ventilator-dependent patients the management of clinically suspected nosocomial pneumonia is often difficult. A diagnosis of pneumonia is based upon findings including pulmonary infiltrate, fever, leukocytosis, or purulent secretions. By using bronchoscopic techniques, we can obtain bronchoalveolar lavage specimens (BAL) from the affected area of the lung. Neutrophils (PMN), which are important for lung defense, are found in increased numbers in BAL of these patients. We therefore ascertained the phagocytic activity of PMN against bacteria and fungi by microscopic examination. BAL specimens from ten mechanically ventilated patients were evaluated to assess the cellular counts using a Bürker hemocytometer, the differential cell counts by cytospin preparations (MGG stain), and the phagocytic activity of PMN and macrophages using the intracellular bacteria index (ICB) values. Microscopical examination of BAL cells and evaluation of ICB values (cut-off > 5%) were higher in four out of twelve patients and the quantitative assessment of bacteria in PMN cytoplasm on cytospin preparations was found to be useful for the diagnosis of pneumonia. In these patients, pneumonia was suspected (in one patient fungal pneumonia) on the basis of microscopical examination of BAL cells and ICB values and the findings were confirmed later by microbiological cultures. In conclusion, in patients on mechanical ventilation a rapid diagnosis of bacterial or fungal pneumonia can be made using BAL cytology and by ICB values, and this in turn allows appropriate therapy to be initiated at an early stage. However, further studies of neutrophil functions are required to improve our understanding of the increased incidence of pulmonary infections in these patients.

Respiratory burst of neutrophils in diabetic patients with periodontal disease.

Periodontal disease, a frequent complication of diabetes mellitus, is the major cause of tooth loss. However, studies on neutrophil function in patients with this condition have yielded contradictory findings. The NADPH oxidase activity of 40 diabetic patients with periodontosis who were on metabolic control was evaluated and compared with that in 40 healthy subjects. Superoxide anion production was measured by a photometric method, with NBT reduction at 490 nm in a microplate reader and by a microscopic method, with a percentage of positive PMNs with granules of formazan in the cytoplasm. When the PMN respiratory burst was activated by phorbol myristate acetate (PMA), a protein kinase C (PKC) soluble activator, superoxide production of diabetics (4.31 +/- 1.67 A x 10(-3)/min) and normal subjects (4.25 +/- 1.25 A x 10(-3)/min) was comparable by photometric method, whereas a significantly defective response to opsonized zymosan was observed when the microscopic method was used (58 +/- 17% in diabetics and 66 +/- 18% in controls; p = 0.05). Therefore in patients with diabetes the impact on PMN function is of multifactorial origin, and is probably correlated to the glucose level and to glycation of PMN protein, such as NADPH oxidase or myeloperoxidase. Alternatively, glucose in PMN may be reduced by aldose reductase to polyols, and this pathway requires NADPH, the coenzyme for the respiratory burst. Moreover, we found that superoxide production in response to opsonized zymosan was reduced in diabetic patients. The activation of protein tyrosine kinase (PTK) is an important mechanism underlying transmembrane signaling and, moreover, protein tyrosine phosphorylations, stimulated by zymosan receptor-mediated activation, might be caused by the activation of specific PTK, whereas activation by PMA is probably mediated through another PKC type.

[Analytical evaluation of an automated hematologic analyzer: Cell Dyn 3500]. / Valutazione analitica di un analizzatore ematologico automatico: il Cell Dyn 3500.

In this study we evaluated the analytical performances of the Cell Dyn 3500, an automated hematology analyzer that provides the electronic and optical detection of leukocyte count and the complete cell counts in samples of whole blood. The protocol included evaluation of complete blood count and differential leukocyte count parameters, using the ICSH and the NCCLS H20-A protocols. Technical performances with regards, to linearity, carry over, precision and stability were quite well acceptable; the accuracy showed a good agreement between Cell Dyn 3500 and instruments used in our laboratory for the major hematologic indices and a good correlation for neutrophils, lymphocytes and eosinophils compared with the manual count.

NADPH oxidase activity and chemotaxis by neutrophils in two patients with glycogen storage disease type Ib treated with recombinant human granulocyte-monocyte colony-stimulating factor.

Polymorphonuclear neutrophils play an important role against pathogens through the production of toxic oxygen metabolites by the NADPH oxidase enzyme, which reduces oxygen to superoxide anion in the respiratory burst. Neutropenia, infectious complications and impaired neutrophil function are often reported in glycogen storage disease type Ib (GSDIb), a metabolic disorder characterized by increased glycogen and decreased glucose-6-phosphatase (G-6-P) activity in the liver. Two children with GSDIb and associated neutropenia with recurrent bacterial infections were treated daily with different doses of rHu-GM-CSF. NADPH oxidase activity and chemotaxis in patients were assessed before and during therapy in stimulated and unstimulated neutrophils. During rHu-GM-CSF treatment, any increase found in the NADPH oxidase activity of patients was not significant with respect to that in controls. In one patient chemotaxis was greater than of controls. This finding suggests that in patients with GSDIb both neutropenia and PMN abnormalities may be responsible for infections, and PMN dysfunction probably depends on the degree of inherited functional G-6-P deficit.

Neutrophil NADPH oxidase activity in chronic myeloproliferative and myelodysplastic diseases by microscopic and photometric assays.

Neutrophil NADPH oxidase is a membrane-bound enzyme complex responsible for the reduction of oxygen to superoxide anion in the respiratory burst. Impaired neutrophil function has often been reported in myeloproliferative diseases and myelodysplastic syndromes (MDSs), but its laboratory features have not been well characterized. Traditionally, NADPH oxidase activity has been evaluated with a microscopic method by nitroblue tetrazolium salt reduction to blue-black insoluble formazan granules identified in positive neutrophils by microscopy. We investigated neutrophil NADPH oxidase in 22 patients with chronic myeloproliferative disorders (cMPDs) and 15 patients with MDSs, using the microscopic method as well as a photometric microplate assay, which monitored the cytochemical reaction for 30 min. The relationship between cMPD and patient susceptibility to infections was also investigated. In the photometric assay, the mean enzyme activity in MDSs and cMPDs was lower than in normal subjects. NADPH oxidase activity was greater in cMPDs (except myelofibrosis) than in MDSs (except chronic myelomonocytic leukemia), and these differences were less evident with microscopy. Moreover, for cMPDs, patients with susceptibility to infections showed a lower NADPH oxidase activity than patients without infections.