Circulating tumour necrosis factor-alpha and interferon-gamma are detectable during acute and convalescent parvovirus B19 infection and are associated with prolonged and chronic fatigue

To investigate whether cytokine responses may have a bearing on the symptom s and outcome of parvovirus B19 infection, circulating cytokines were measu red during acute infection (n = 51), follow-up of acute infection (n = 39) and in normal healthy controls (n = 50). At acute B19 virus infection (seru m anti-B19 IgM-positive), patients ranged in age from 4 to 54 years, with a mean age of 28-2 years. The male: female ratio was 1:41 and symptoms were rash (n = 15), arthralgia (n = 31), fatigue (n = 8), lymphadenopathy (n = 4 ), foetal hydrops (n = 3), transient aplastic crisis (n = 2), neutropenia ( n = 2), myelodysplasia (n = 1), thrombocytopenia (n = 1) and pancytopenia ( n = 1). Of these patients, 39 were contacted after a follow-up period of 2- 37 months (mean of 22-5 months). In comparison with normal controls, detect able IL-6 was associated with acute B19 virus infection (26%; P = 0.0003), but not with follow-up (6%; P = 0.16). Detection of interferon (IFN)-gamma was associated with acute B19 virus infection (67%; P < 0.0001) and follow- up (67%;P < 0.0001). Detection of tumour necrosis factor (TNF)-alpha was as sociated with acute B19 virus infection (49%; P < 0.0001) and follow-up (56 %; P < 0.0001). IL-1 beta was detected in acute infection (20%), but not at follow-up. At acute B19 virus infection, detection of serum/plasma IL-6 wa s associated with rheumatoid factor (P = 0.038) and IFN-gamma (greater than or equal to 7 pg/ml) was associated with fatigue in those patients of > 15 years of age (P = 0.022). At follow-up, fatigue was associated with IFN-ga mma (> 7 pg/ml) and/or TNF-alpha (> 40 pg/ml) (P = 0.0275). Prolonged upreg ulation of serum IFN-gamma and TNF-alpha appears to represent a consistent host response to symptomatic B19 virus infection.