Heterophil-negative infectious mononucleosis and mononucleosis-like illnesses. Laboratory confirmation of 43 cases

Role of infection in Guillain-Barré syndrome: laboratory confirmation of herpesviruses in 41 cases

Serological evidence of either acute cytomegalovirus (CMV) or Epstein-Barr virus (EBV) infection was sought in a large series of patients with Guillain-Barré syndrome (GBS) and control subjects. Using an indirect immunofluorescent technique, IgM antibody directed against CMV was found in the serum of 33 of 220 GBS patients. The CMV-positive patients were mainly young adults (average age, 25.6 years), previously healthy, and the most common prodromal illness was mild coryza. Alternations in serum CMV IgM antibody level closely paralleled the patients' clinical course. Persistently elevated titers were found in patients with severe and protracted paralysis, whereas rapid disappearance of virus-specific IgM characterized benign cases. Striking time clusters of CMV-seropositive patients were found during three periods between January, 1971, and October, 1973. In a parallel study, EBV-specific IgM was found in 8 of 100 GBS patients (8%). All 8 also had heterophil antibodies. Thus, EBV and CMV appear related to a substantial number of cases of this primary demyelinating disease and, to date, are the two most common agents we have been able to link with GBS.

The lymphoid leukocytoses

The experienced morphologist can be extremely helpful to the clinician by virtue of his or her ability to distinguish among the various subtypes of reactive lymphocytoses. An awareness on the part of the clinician as to the nuances of subclassification may lead to earlier diagnosis of a disease process. Broadly, proliferations of normal lymphocytes point to infectious lymphocytosis or Bordetella pertussis infection. Proliferations of atypical lymphocytes, especially when minimum diagnostic criteria are present or there are four or more Downey III forms per 100 WBCs, suggest infectious mononucleosis. Proliferations of immunoblasts reflect hypersensitivity reactions to drugs or autoimmune disease. Proliferations of proplasmacytes or plasma cells favor viral hepatitis, drug reactions (notably to sulfa drugs), or rubella. Quantitative data may help refine the morphologic implications. Cumulatively, qualitative and quantitative data should lead the clinician to a judicious selection of confirmatory serologic tests and hence to earlier diagnosis.

Diagnostic aspects of the cytomegalovirus mononucleosis syndrome in previously healthy persons

The mononucleosis-like syndrome due to cytomegalovirus (CMV) has many clinical features in common with classic Epstein-Barr virus (EBV) induced infectious mononucleosis (IM). The hematologic and hepatic findings in both diseases are identical. Diagnosis of the CMV-IM syndrome usually can be made on the basis of indirect immunofluorescence for CMV macroglobulins (CMV-IgM). EBV virologic tests may also be necessary, as patients with primary EBV infections may have cross-reactions at low titer in the CMV-IgM test.

Cytomegalovirus granulomatous hepatitis

Three patients with granulomatous hepatitis due to cytomegalovirus are described. They are compared to the three previously described patients with this disease, and their clinical and serologic characteristics are discussed. Similarities and differences between infectious mononucleosis (Epstein-Barr virus) and cytomegalovirus infections are adduced. That cytomegalovirus may be a cause of granulomatous hepatitis in the adult is stressed.