Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024312 (lymphopenia)
 4,859 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Animal models of Pneumocystis carinii (Pc) pneumonia (PCP) play a central role in research on the Pc microorganism itself and the disease, especially the pathogenesis and the host defence. The classic rat model with corticosteroid-induced reactivation of a latent infection has been most widely used. In our search for alternative non-rodent models, six 31/2-week-old piglets were injected intramuscularly with methylprednisolone acetate, at 18 mg/kg body weight, once a week for 6 weeks. Six littermate piglets constituted the control group. The principals showed a markedly lower growth rate than the controls. Furthermore, they developed "moon face" and "pot belly", snoring sounds while eating, and pronounced respiratory distress during handling. Significant changes in haematological parameters, including lymphopenia, were observed in the principal group. The Pc antibody titres of the controls increased to high levels, whereas the principals were all low-titred or seronegative for Pc at the last blood sampling. At necropsy, the mean body weight of the principals was about half that of the controls. In addition, they had an extreme reduction of the thymus together with dark red consolidations of the frontal lung lobes and/or atelectatic looking diaphragmatic lobes. Histopathologically, there was a focal interstitial pneumonia. Alveolar walls and interstitia had mononuclear cell infiltrations and the alveolar lumina were occluded by foamy acidophilic honeycomb material with a varying number of Pc cysts. The reduced body weight, the thymus involution, and the lymphopenia, together with the reduced levels of specific Pc antibodies and the histomorphology of the PCP, were consistent parameters of the principal group and comparable to the findings of the classic rat model. Thus, the present study is the first to describe that prolonged administration of high doses of methylprednisolone acetate can induce PCP in piglets.
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PMID:Experimental corticosteroid induction of Pneumocystis carinii pneumonia in piglets. 1054 89

Lymphocytopenia has been reported in patients with connective tissue diseases, including dermatomyositis (DM). However, the risk of infectious complications and the changes of lymphocytic subsets during treatment have been poorly investigated in these patients. We investigated the alterations of peripheral blood lymphocyte counts in patients with DM. A retrospective analysis was conducted in patients with an ascertained diagnosis of DM admitted from 1994 to 2000 in both departments of Dermatology of the Saint-Louis Hospital in Paris. All patients had a peripheral blood absolute lymphocyte count available before therapy. From an initial set of 63 patients, 47 were included in the study. The median absolute lymphocyte count was 888/mm(3) (range, 400-4,070). Low peripheral blood CD4+ and CD8+ T-cell and B-cell counts were consistent findings (median CD4+: 382/mm(3); CD8+: 211/mm(3); CD19+: 122/mm(3)). There was a significant increase in lymphocyte count after 1 month (p < 0.0001), 3-6 months (p = 0.001), and 6-12 months (p = 0.0005) of corticosteroid treatment. Infectious events, mainly pneumonia (PCP), occurred in 12 patients. Their initial lymphocyte count was lower than that of patients who did not develop infections (p = 0.0001). These results support the high prevalence of lymphocytopenia in patients with DM and emphasize the risk for opportunistic infections, mainly PCP, in these patients. Further studies are warranted to evaluate the risk/benefit balance of PCP prophylaxis in patients with DM and severe lymphocytopenia.
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PMID:Peripheral blood lymphocyte subset counts in patients with dermatomyositis: clinical correlations and changes following therapy. 1264 Jan 84

Pneumocystis jiroveci (formerly carinii) pneumonia (PCP) is a serious opportunistic infection in children and adolescents with cancer. It was the most common cause of death among children receiving chemotherapy prior to the inclusion of PCP prophylaxis as part of standard care for children with leukemia. The incidence of PCP has decreased significantly since initiation of prophylaxis; however, breakthrough cases continue to occur. Hematologic malignancies, brain tumors necessitating prolonged corticosteroid therapy, hematopoietic stem cell transplantation, prolonged neutropenia, and lymphopenia are the most important risk factors for PCP in children not infected with HIV. Of children with leukemia, 15-20% may develop PCP in the absence of prophylaxis. Infection with P. jiroveci occurs early in life in most individuals. However, clinically apparent disease occurs almost exclusively in immunocompromised persons. Dyspnea, cough, hypoxia, and fever are the most common presenting symptoms of PCP. Chest radiography and high-resolution CT scans of the chest demonstrate a characteristic ground-glass pattern. Induced sputum analysis and bronchoalveolar lavage are the diagnostic procedures of choice. Gomori's methenamine-silver stain, Geimsa or Wright's stain, and monoclonal immunofluorescent antibody stains are most commonly used to make a diagnosis. However, identification of P. jiroveci DNA using polymerase chain reaction assays in bronchoalveolar lavage fluid is more sensitive. Trimethoprim-sulfamethoxazole (TMP-SMZ; cotrimoxazole) is the recommended drug for the treatment of PCP. Patients who are intolerant of TMP-SMZ or who have not responded to treatment after 5-7 days of therapy with TMP-SMZ should be treated with pentamidine. A short course of corticosteroids is recommended for moderate to severe cases of PCP within the first 72 hours after diagnosis. Mutations in the dihydropteroate synthetase gene may confer resistance to TMP-SMZ; however, the clinical relevance of these mutations is not well established. TMP-SMZ is the most commonly used agent for prophylaxis. Myelosuppression is the most important adverse effect of TMP-SMZ and the most frequent cause for choosing alternative prophylactic agents in children undergoing chemotherapy. Alternative agents for chemoprophylaxis include dapsone, aerosolized pentamidine, and atovaquone. Alternative prophylactic agents must be used in patients developing myelosuppression secondary to TMP-SMZ or dapsone.
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PMID:Management of Pneumocystis jiroveci pneumonia in children receiving chemotherapy. 1792 2