Several studies have shown that some liver transplant recipients may tolerate immunosuppression withdrawal. Mechanisms and biomarkers of tolerance are not well known. Methods: Twenty-four LT patients with immunosuppression side-effects underwent progressive immunosuppression withdrawal. Peripheral lymphocyte populations and secretion of cytokines were analyzed at baseline and during withdrawal until tolerance (n = 15) or rejection (n = 9), as well as 3. months after tolerance achievement or rejection resolution (as follow-up). Immunological markers were compared among groups. Results: The percentages of CD3 + CD4 + cells progressively decreased in both groups. CD3 + CD8 + cells gradually increased in tolerant patients. B lymphocytes gradually decreased in tolerant and initially in non-tolerant patients, reverting at rejection. Regulatory T cells progressively increased until rejection in non-tolerants, decreasing to basal levels after renewing immunosuppression; no significant changes were found in tolerant patients. The percentages and absolute counts of natural killer cells significantly increased in both groups, being more evident in tolerant patients. The secretion of several cytokines was higher in non-tolerant patients when rejection was diagnosed. Conclusions: The greater increase of natural killer cells in tolerant patients suggests their potential role in the tolerance phenomenon

Recipients of liver transplantation (LT) may develop immunological tolerance. Factors predictive of tolerance are not clearly understood. Transplant recipients with normal liver function tests and without active viral hepatitis or autoimmune disease who presented with side effects of immunosuppression or a high risk of de novo malignancies were selected to participate in this prospective study. Twenty-four patients fulfilled the inclusion criteria and, therefore, underwent a gradual reduction of immunosuppression. Tolerance was defined as normal liver function tests after immunosuppression withdrawal. Basal clinical and immunological characteristics, including lymphocyte counts and subpopulations (T, B, natural killer, CD4+, CD8+, and regulatory T cells) and the phytohemagglutinin stimulation index (SI), were compared for tolerant and nontolerant patients. Fifteen of the 24 patients (62.5%) were tolerant at a median of 14 months (interquartile range¿=¿8.5-22.5 months) after complete immunosuppression withdrawal. Tolerant patients had a longer median interval between transplantation and inclusion in the study (156 for tolerant patients versus 71 months for nontolerant patients, P¿=¿0.003) and a lower median SI (7.49 for tolerant patients versus 41.73 for nontolerant patients, P¿=¿0.01). We identified 3 groups of patients with different probabilities of tolerance: in the first group (n¿=¿7 for an interval¿>¿10 years and an SI¿<¿20), 100% reached tolerance; in the second group (n¿=¿10 for an interval¿>¿10 years and an SI¿>¿20 or an interval¿<¿10 years and an SI¿<¿20), 60% reached tolerance; and in the third group (n¿=¿7 for an interval¿<¿10 years and an SI¿>¿20), 29% reached tolerance. In conclusion, a high proportion of select LT recipients can reach tolerance over the long term. Two simple basal variables¿the time from transplantation and the SI¿may help to identify these patients.

Listeriosis can be a cause of arthritis. Here, we present a case of Listeria monocytogenes septic arthritis of the right hip in a 66-year-old male treated with mycophenolate mofetil for polyarteritis nodosa. So far, septic arthritis due to this microorganism has not been reported in patients treated with mycophenolate mofetil. We review the literature of L. monocytogenes septic arthritis and discuss the role of mycophenolate mofetil treatment in precipitating listeriosis.