Normal LDH Levels Research Articles

Diagnosis of Pneumocystis carinii Pneumonia by Induced Sputum in a City with Moderate Incidence of AIDS

Examination of induced sputum from AIDS patients has been reported to provide the noninvasive diagnosis of PCP in 10 to 76 percent of cases. Since previous studies were done in centers with a high incidence of AIDS, we asked whether this test could be implemented successfully in a center with a lower incidence of AIDS. Over a 13-month period 25 of 38 (66 percent) AIDS patients with PCP had positive Giemsa (Diff-Quik) stains of induced sputum. We were unable to predict before sputum induction which patients would be positive based on clinical severity (increased A-a gradient or serum LDH levels). We confirmed prior observations that a normal serum LDH level was found in only 5 percent of documented PCP cases. This noninvasive technique significantly decreased the number of bronchoscopies performed and led to a considerable cost savings.

Prognostic influence of TNM staging and LDH levels in small cell carcinoma of the lung (SCCL).

To better define the prognostic factors influencing the response to therapy and survival in small cell carcinoma of the lung (SCCL), an expanded "TNM" type staging system was developed and investigated in a series of 73 protocol treated patients. Because serum LDH levels at disease presentation have been correlated to disease extent, response to therapy, and treatment outcome in a number of malignancies, including SCCL, these interrelationships were also analyzed in the protocol patients. The TNM system was found to be a more descriptive and specific "shorthand" for denoting sites of involvement and for indicating the body burden of tumor than the traditional limited-extensive disease (LD-ED) system. A clear statistical advantage could not be shown over the LD-ED system for predicting chemotherapy response or survival, although there were trends suggesting the TNM system could divide patients into three prognostic subgroups. Serum LDH proved to be a useful index of disease extent and therapy outcome. LDH levels at presentation were proportionately higher with more extensive tumor, measured by either the LD-ED or TNM staging. High LDH predicted poorer responses to chemotherapy and lower survival within similar stage subgroups compared to patients with normal LDH levels. The negative effect of elevated LDH was independent of hepatic involvement and did not predict subsequent hepatic failure in any consistent way. The SCCL TNM staging system proposed needs further refinement and should be tested with larger patient numbers. LDH, along with other tumor markers recently identified, need to be integrated into the staging system to form an overall prognostic index.

Influence of LDH viruses on growth of Ehrlich ascites tumor in mice.

Summary1. Ehrlich Mouse Ascites Carcinoma (EMC) was freed from an endogenous LDH virus by passage in tissue culture, and subsequently carried virus-free for 27 generations in mice. 2. Plasma LDH was from 10- to 40-fold elevated in mice carrying the stock infected tumor. Over 90% of mice carrying the virus-free tumor, however, had normal plasma LDH levels. 3. Growth rate of the virus-free tumor was accelerated by the LDH virus from Ehrlich Mouse Carcinoma itself and also by LDH agents isolated from DBA/59 mammary carcinoma and CD/5 lymphoma. It is suggested that the virus may depress host resistance to the tumor.