Mycoplasmal Pneumonia Workup
- Author: Michael Joseph Bono, MD, FACEP; Chief Editor: Robert E O'Connor, MD, MPH more...
Approach Considerations
Laboratory tests are generally of limited benefit in mycoplasmal pneumonia, as they tend to be nonspecific or within the normal range. For example, elevated erythrocyte sedimentation rates (ESR) may be present but are nonspecific. The white blood cell (WBC) count is generally not helpful in this condition, because results may be normal or elevated, and, although hemolytic anemia has been described, it is rare.
Radiography
Chest radiographic findings vary, but abnormalities are usually more striking than the findings upon physical examination. Bronchopneumonia often involves a single lower lobe, although lobar consolidation is rare. Platelike atelectasis is noted as thin, flat areas of collapsed lung and is often seen on a lateral image of the chest. Pleural effusions develop in less than 20% of patients; when present, they can be seen on lateral decubitus films.
Reticulonodular or interstitial infiltrates, primarily in the lower lobes, may resemble other diseases with granulomatous pathology, such as tuberculosis, mycoses, and sarcoidosis; hilar adenopathy is sometimes mistaken for malignancy.
CT Scanning
High-resolution computed tomography (CT) scans of the chest are more sensitive than chest radiography in elucidating lung disease.[16]
Sputum Culture
Sputum Gram stains and cultures are usually not helpful, because M pneumoniae lacks a cell wall and cannot be stained. In fact, M pneumoniae is difficult to culture and requires 7-21 days to grow; culturing is successful in only 40-90% of cases and does not provide information to guide patient management.
Serology
Serum cold agglutination is a nonspecific test for M pneumoniae, but findings are positive in 50-70% of patients after 7-10 days of infection. Serology tests that demonstrate a 4-fold or greater increase or decrease in paired sera titers or a single titer greater than or equal to 1:32 supports the diagnosis of mycoplasmal pneumonia. A quick bedside test can be performed by partially filling a purple-top tube with blood and placing it in ice; a positive finding is one in which "grains of sand" appear on the glass portion of the tube.
Cold agglutinin tests can be obtained from diagnostic laboratories. A negative result does not exclude infection, and this test may be affected by cross-reactions with other pathogens, such as adenovirus, Epstein-Barr virus, and measles viruses.
Other serologic tests include complement fixation, enzyme-linked immunoassay, and indirect hemagglutination. All of these have acceptable sensitivity and specificity.
Polymerase Chain Reaction
Polymerase chain reaction (PCR) has been shown to accurately diagnose atypical pneumonia.[17] This test has been used for epidemiologic studies but is not currently used in most clinical settings. Real-time PCR is a promising test that allows detection of M pneumoniae DNA in all phases of infection, including early periods when the serum may be negative for antibody.[18, 19]
DNA Probes
A radiolabeled DNA probe detects M pneumoniae ribosomal RNA in respiratory secretions with 90% sensitivity.
Eosinophil Cationic Protein
The role of eosinophil cationic protein (ECP) has been studied in M pneumoniae infection and asthma, in which ECP levels have been found to be increased.[20] This protein may play a role in damage to the respiratory epithelium and accelerated hypersensitivity in the respiratory system, although more studies are required.
McCormack WM. Infections due to Mycoplasmas. In: Kasper DL, Braunwald E, Fauci AS, et al, eds. Harrison's Principles of Internal Medicine. 16th ed. New York: McGraw-Hill; 2005:1008-11, 159.
Reimann HA. An acute infection of the respiratory tract with atypical pneumonia: a disease entity probably caused by a filtrable virus. JAMA. 1938;111:2377-84.
Eaton MD, Meiklejohn G, VanHerick W. Studies on the etiology of primary atypical pneumonia: a filterable agent transmissible to cotton rats, hamsters, and chick embryos. J Exp Med. 1944;79:649-67.
Kamizono S, Ohya H, Higuchi S, Okazaki N, Narita M. Three familial cases of drug-resistant Mycoplasma pneumoniae infection. Eur J Pediatr. Jun 2010;169(6):721-6. [Medline].
Isozumi R, Yoshimine H, Morozumi M, Ubukata K, Ariyoshi K. Adult community-acquired pneumonia caused by macrolide resistant Mycoplasma pneumoniae. Respirology. Nov 2009;14(8):1206-8. [Medline].
Matsubara K, Morozumi M, Okada T, Matsushima T, Komiyama O, Shoji M, et al. A comparative clinical study of macrolide-sensitive and macrolide-resistant Mycoplasma pneumoniae infections in pediatric patients. J Infect Chemother. Dec 2009;15(6):380-3. [Medline].
Lee SW, Yang SS, Chang CS, Yeh HJ, Chow WK. Mycoplasma pneumonia-associated acute hepatitis in an adult patient without lung infection. J Chin Med Assoc. Apr 2009;72(4):204-6. [Medline].
Quioc JJ, Trabut JB, Drouhin F, Malbrunot C, Vallet-Pichard A, Pol S, et al. Acute cholestatic hepatitis revealing Mycoplasma pneumoniae infection without lung involvement in an adult patient. Eur J Gastroenterol Hepatol. Feb 2009;21(2):220-1. [Medline].
Okoli K, Gupta A, Irani F, Kasmani R. Immune thrombocytopenia associated with Mycoplasma pneumoniae infection: a case report and review of literature. Blood Coagul Fibrinolysis. Oct 2009;20(7):595-8. [Medline].
Khan FY, A yassin M. Mycoplasma pneumoniae associated with severe autoimmune hemolytic anemia: case report and literature review. Braz J Infect Dis. Feb 2009;13(1):77-9. [Medline].
Wetter DA, Camilleri MJ. Clinical, etiologic, and histopathologic features of Stevens-Johnson syndrome during an 8-year period at Mayo Clinic. Mayo Clin Proc. Feb 2010;85(2):131-8. [Medline]. [Full Text].
Azumagawa K, Kambara Y, Murata T, Tamai H. Four cases of arthritis associated with Mycoplasma pneumoniae infection. Pediatr Int. Aug 2008;50(4):511-3. [Medline].
Csábi G, Komáromy H, Hollódy K. Transverse myelitis as a rare, serious complication of Mycoplasma pneumoniae infection. Pediatr Neurol. Oct 2009;41(4):312-3. [Medline].
Narita M. Pathogenesis of neurologic manifestations of Mycoplasma pneumoniae infection. Pediatr Neurol. Sep 2009;41(3):159-66. [Medline].
Neumayr L, Lennette E, Kelly D, Earles A, Embury S, Groncy P, et al. Mycoplasma disease and acute chest syndrome in sickle cell disease. Pediatrics. Jul 2003;112(1 Pt 1):87-95. [Medline].
Reittner P, Müller NL, Heyneman L, Johkoh T, Park JS, Lee KS, et al. Mycoplasma pneumoniae pneumonia: radiographic and high-resolution CT features in 28 patients. AJR Am J Roentgenol. Jan 2000;174(1):37-41. [Medline].
Blackmore TK, Reznikov M, Gordon DL. Clinical utility of the polymerase chain reaction to diagnose Mycoplasma pneumoniae infection. Pathology. Apr 1995;27(2):177-81. [Medline].
Di Marco E, Cangemi G, Filippetti M, Melioli G, Biassoni R. Development and clinical validation of a real-time PCR using a uni-molecular Scorpion-based probe for the detection of Mycoplasma pneumoniae in clinical isolates. New Microbiol. Oct 2007;30(4):415-21. [Medline].
Gullsby K, Storm M, Bondeson K. Simultaneous detection of Chlamydophila pneumoniae and Mycoplasma pneumoniae by use of molecular beacons in a duplex real-time PCR. J Clin Microbiol. Feb 2008;46(2):727-31. [Medline]. [Full Text].
Chen CJ, Hung MC, Kuo KL, Chung JL, Wu KG, Hwang BT, et al. The role of eosinophil cationic protein in patients with Mycoplasma pneumoniae infection. J Chin Med Assoc. Jan 2008;71(1):37-9. [Medline].
Llibre JM, Urban A, Garcia E, Carrasco MA, Murcia C. Bronchiolitis obliterans organizing pneumonia associated with acute Mycoplasma pneumoniae infection. Clin Infect Dis. Dec 1997;25(6):1340-2. [Medline].
Koskiniemi M. CNS manifestations associated with Mycoplasma pneumoniae infections: summary of cases at the University of Helsinki and review. Clin Infect Dis. Aug 1993;17 Suppl 1:S52-7. [Medline].
Smith LG. Mycoplasma pneumonia and its complications. Infect Dis Clin North Am. Mar 2010;24(1):57-60. [Medline].
Brown SM, Padley S, Bush A, Cummins D, Davidson S, Buchdahl R. Mycoplasma pneumonia and pulmonary embolism in a child due to acquired prothrombotic factors. Pediatr Pulmonol. Feb 2008;43(2):200-2. [Medline].
Drugs of choice for community-acquired bacterial pneumonia. Med Lett Drugs Ther. Jul 30 2007;49(1266):62-4. [Medline].
Yang E, Altes T, Anupindi SA. Early Mycoplasma pneumoniae infection presenting as multiple pulmonary masses: an unusual presentation in a child. Pediatr Radiol. Apr 2008;38(4):477-80. [Medline].
Print
