Positive Monospot Test Research Articles

Persistent Falsely Positive Rapid Tests for Infectious Mononucleosis: Report of Five Cases with Four–Six-year Follow-up Data

In many laboratories, rapid slide tests incorporating differential absorption have replaced heterophil antibody tube tests in the investigation of suspect infectious mononucleosis. The present report describes serologic data from five individuals whose Monospot tests remained falsely positive for four years or more without other evidence of infectious mononucleosis or underlying disease states. Three of the five had never been infected with the Epstein-Barr virus. All five had negative results when studied with the ox cell hemolysin and the horse cell differential absorption tube tests. False-positive test results have also been encountered in healthy controls, as frequently as in patients with underlying disease states. The authors are unable to attach any clinical significance to the findings of an isolated falsely positive Monospot test even when it persists for many months or years.

Mumps Occurring as a Mononucleosis-like Syndrome With Positive Monospot Test

<h3>To the Editor.—</h3> Two patients had a clinical picture of infectious mononucleosis and a positive Monospot test on admission. However, a notable rise in antibody titer to mumps virus was also found. Serological follow-up studies were performed to determine whether these patients had possible concurrent infections with Epstein-Barr virus and mumps virus. The cases of five typical patients with mumps, who were admitted during the same month, were investigated as controls. <h3>Report of Cases.—Case 1.—</h3> An 18-year-old man became ill with high fever (39^°C), cervical lymphadenopathy, and membranous tonsillitis. He had 2,300 WBCs, with 50% lymphocytes. He was febrile for 12 days, during which time the enlarged lymph nodes and tonsils returned to normal size and appearance. At approximately that time, it became apparent that the parotid glands were slightly enlarged also. <h3>Case 2.—</h3> A 12-year-old boy was admitted because of fever and membranous tonsillitis. He

Mumps occurring as a mononucleosis-like syndrome with positive Monospot test

To the Editor.— Two patients had a clinical picture of infectious mononucleosis and a positive Monospot test on admission. However, a notable rise in antibody titer to mumps virus was also found. Serological follow-up studies were performed to determine whether these patients had possible concurrent infections with Epstein-Barr virus and mumps virus. The cases of five typical patients with mumps, who were admitted during the same month, were investigated as controls. Report of Cases.—Case 1.— An 18-year-old man became ill with high fever (39 ° C), cervical lymphadenopathy, and membranous tonsillitis. He had 2,300 WBCs, with 50% lymphocytes. He was febrile for 12 days, during which time the enlarged lymph nodes and tonsils returned to normal size and appearance. At approximately that time, it became apparent that the parotid glands were slightly enlarged also. Case 2.— A 12-year-old boy was admitted because of fever and membranous tonsillitis. He

A positive Monospot test in a diabetic with sarcoidosis.

A positive Monospot test in a diabetic with sarcoidosis.

Positive Mono-spot Test in Histiocytic Medullary Reticulosis

A case of rapidly fatal histiocytic medullary reticulosis in which two positive mono-spot tests were found is presented. In addition, there was a low liter antibody to EB virus. The patient died with a bleeding diathesis terminally. Postmortem examinations confirmed the diagnosis of histiocytic medullary reticulosis.

Hemolytic anemia associated with multiple autoantibodies and low serum complement

A 37 year old woman with extravascular hemolytic anemia had a positive Monospot test associated with positive antiglobulin and anticomplement Coombs' tests, cold agglutinins and warm autoantibodies. IgG-kappa (κ) antibodies, which reacted with all panel red cells at 37 °C, were eluted from her circulating red cells. However, neither immunoglobulins nor C3 was detected after her serum was adsorbed with heterologous red cell stroma at 37 °C and eluted at the same temperature in glycine buffer. In contrast, IgM-κ and IgM-Iambda (λ), IgG3-κ, IgG4-λ, IgA-λ and C3 were eluted at 37 °C from heterologous red cell stroma after adsorption with her serum at 0 °C. Thus, antibodies of several types, which were present in the patient's serum, reacted optimally with red cell antigens at low temperature. Cold-reactive IgG3-κ antibodies, which were also capable of interacting with red cells at 37 °C, probably accounted for the IgG-κ antibodies eluted from the patient's circulating red cells. The patient's serum C4 titers were decreased, with low normal to moderately depressed C3 and low normal C5, indicating that the anti-red cell IgM and/or IgG3-κ antibodies probably fixed complement. A localized cold stress test resulted in a transient increase in plasma hemoglobin and a decrease in serum C3 titer. These findings, and the beneficial clinical response obtained with small doses of prednisone, suggest that both the cold-reactive antibodies and the IgG-κ on circulating red cells were pathophysiologically significant. This is the first report of a patient with multiple red cell autoantibodies in whom serum complement component titers were determined in conjunction with characterization of the anti-red cell immunoglobulins. Subclinical infectious mononucleosis may have preceded the prolonged hemolytic episode. Clinical evidence of systemic lupus erythematosus has not appeared.

False-positive Monospot tests in malaria.

Two of fourteen consecutive patients with malaria had positive Monospot tests. Neither had a history of other recent febrile illness, and tests for heterophil and Epstein-Barr virus antibodies were negative. Another instance of a positive Monospot test in a patient with malaria in which the positive Monospot test contributed to a delay in the diagnosis of malaria has been reported. Because infectious mononucleosis and malaria can initially cause similar signs and symptoms, physicians should be aware of this possibility to avoid such delays in diagnosis and institution of proper treatment.

False-Positive Monospot or Rubella and Mononucleosis

To the Editor.— Phillips1reported a case clinically consistent with rubella, in which a positive Monospot test result was noted. Because of persistently negative heterophil antibody titers he concluded that the patient did not have mononucleosis and, therefore, the Monospot test result was a false-positive. However, Evans et al2previously reported a syndrome of heterophil-negative infectious mononucleosis and indicated that many of these patients have elevated EB virus antibody titers. Phillips1reported that EB virus titers could not be obtained in his case. One wonders if this were truly an instance of a false-positive Monospot result or whether it was in fact a case of coexistence of two viral infections—rubella and EB virus. With this in mind, we would like to describe a similar case that is even more suggestive of the coexistence of these two viral diseases. Report of a Case.— A 20-year-old boy from El Salvador