Acute parvovirus B19-induced pancytopenia in the setting of methotrexate therapy for rheumatoid arthritis

Is routine viral screening useful in patients with recent-onset polyarthritis of a duration of at least 6 weeks? Results from a nationwide longitudinal prospective cohort study

OBJECTIVE

To study the contribution of routine viral screening tests in patients with early rheumatoid arthritis (RA) or a potential for progressing to RA.

METHODS

Eight hundred thirteen patients with swelling of at least 2 joints for at least 6 weeks and a symptom duration of less than 6 months in the ESPOIR cohort were screened for parvovirus B19 (IgG and IgM anti-parvovirus B19 antibodies), hepatitis B virus (HBV; hepatitis B surface antigen), hepatitis C virus (HCV; anti-HCV antibodies), and human immunodeficiency virus (HIV; anti-HIV-1 and -2 antibodies).

RESULTS

Parvovirus B19 testing was performed in 806 patients and showed longstanding immunity in 574 (71.2%) and no antibodies in 223 (27.7%). Among the 9 remaining patients (7 IgG positive/IgM positive, 1 IgG negative/IgM positive, and 1 IgG indeterminate/IgM positive), only 2 (0.25%; 95% confidence interval [95% CI] 0-0.99%) had a positive polymerase chain reaction test for parvovirus B19; these patients (women ages 34 and 40 years) had no extraarticular signs. HIV seroprevalence was 0.12% (n = 1 of 813; 95% CI 0.01-0.8%) and HCV seroprevalence was 0.86% (n = 7 of 808, 95% CI 0.38-1.86%). HCV-related arthritis was diagnosed in 4 patients (0.5%). HCV-seropositive patients had significantly higher transaminase levels than the other patients (P = 0.001), with no significant differences for the other laboratory data. HBV seroprevalence was 0.12% (n = 1 of 808; 95% CI 0.01-0.8%); the positive HBV status was known before study inclusion, and the patient had no diagnosis of HBV-related arthritis. Finally, routine viral testing identified 2 patients with parvovirus B19 infection and 3 with HBV infection (0.6%; 95% CI 0.2-1.5%). Cost was €85.05 per patient (total €68,720).

CONCLUSION

Routine serologic testing did not contribute substantially to the diagnosis in this context.

Parvovirus B19 causing leucopenia and neutropenia in a healthy adult

A 27-year-old healthy female presented with a prolonged and intermittent febrile illness. She was found to have leucopenia, neutropenia and thrombocytopenia, but a normal haemoglobin. The patient recovered spontaneously and convalescent serology 1 month later was positive for specific parvovirus B19 IgM and IgG. Parvovirus B19 infection was confirmed by detection of viral DNA by dot blot hybridization in a specimen of blood taken during the acute illness. A review of the previously reported cases of parvovirus B19-induced leucopenia in normal adults is presented. Parvovirus B19 should be considered in the differential diagnosis of leucopenia and neutropenia in healthy adults.

The remarkable spectrum of methotrexate toxicities

This article outlines a general scheme for categorizing medication-related adverse events. This is followed by a review of the less well-recognized adverse events attributed to low-dose methotrexate therapy. Known and suspected risk factors are described and causative mechanisms are suggested. Ultimately, this article aims at increasing the readers awareness of uncommon or underreported methotrexate-associated adverse events so that prescribing and monitoring practices can be tailored to enhance the safe use of this valuable antirheumatic agent.