Infectious complications continue to have a major impact on survival in patients with chronic lymphocytic leukaemia despite advances in immune therapy, haematologists  say.

Overall survival rates among CLL patients with infection are approximately half those of patients with no infection, according to a review of long term outcomes of patients treated by clinicians from the Department of Haematology, Royal North Shore Hospital, Sydney.

In a review of 9.5 years of follow up data for 150 patients with CLL, Dr Kyle Crassini and colleagues of the Chronic Lymphocytic Leukaemia Australian Research Consortium (CLLARC) found that 45% of patients had disease progression requiring treatment.

When they reviewed overall survival rates in terms of infectious complications, they found that at six years the  cumulative survival rates were around 40% for patients with infection and 80% for patients with no infection.

Writing in Haematologica, they say the findings mirror those of a recently published  Danish registry study covering 2905 CLL patients in which infection was found to be a major cause of mortality and morbidity.

The Danish study found that infections were common, with 23% of patients having an infection prior to treatment and 11% requiring treatment within a year of documented infection. Of those patients with an infectious complication, 10% died within 30 days and 35% died within a year.

Age, sex, Binet stage, Beta-2 microglobulin and unmutated IGHV were all associated with higher risk of infection, as were IgA, IgM and IgG deficiency.

The Australian authors note that treatment outcomes in CLL have been revolutionised by immune therapy regimens such as ibrutinib and venetoclax, but stress that the relationship between immune dysfunction and survival is still highly significant.

“These studies demonstrate that infection remains a major risk in CLL, with a highly significant impact on survival, and remains a challenge in the management of CLL in spite of the obvious advances in therapy,” they conclude.