Leptospirosis in Retirees Living in Rural Areas: A Poorly Recognized Emerging Problem in Mainland France?

Among 40 patients diagnosed with leptospirosis in 3 hospitals of western mainland France between 2014 and 2018, half were at least 60 years old and retired. Their exposure factors were mainly rural residential environment with limited remarkable risk factors. Better awareness and information on leptospirosis appear necessary in this population.

Patients with drug-free long-term graft function display increased numbers of peripheral B cells with a memory and inhibitory phenotype.

Several transplant patients maintain stable kidney graft function in the absence of immunosuppression. Here we compared the characteristics of their peripheral B cells to that of others who had stable graft function but were under pharmacologic immunosuppression, to patients with chronic rejection and to healthy volunteers. In drug-free long-term graft function (DF) there was a significant increase in both absolute cell number and frequency of total B cells; particularly activated, memory and early memory B cells. These increased B-cell numbers were associated with a significantly enriched transcriptional B-cell profile. Costimulatory/migratory molecules (B7-2/CD80, CD40, and CD62L) were upregulated in B cells; particularly in memory CD19(+)IgD(-)CD38(+/-)CD27(+) B cells in these patients. Their purified B cells, however, responded normally to a polyclonal stimulation and did not have cytokine polarization. This phenotype was associated with the following specific characteristics which include an inhibitory signal (decreased FcgammaRIIA/FcgammaRIIB ratio); a preventive signal of hyperactive B-cell response (an increase in BANK1, which negatively modulates CD40-mediated AKT activation); an increased number of B cells expressing CD1d and CD5; an increased BAFF-R/BAFF ratio that could explain why these patients have more peripheral B cells; and a specific autoantibody profile. Thus, our findings show that patients with DF have a particular blood B-cell phenotype that may contribute to the maintenance of long-term graft function.

Two novel variants in CNTNAP1 in two siblings presenting with congenital hypotonia and hypomyelinating neuropathy.

Homozygous frameshift variants in CNTNAP1 have recently been reported in patients with arthrogryposis and abnormal axon myelination. In two brothers with severe congenital hypotonia and foot deformities, we identified compound heterozygous variants in CNTNAP1, reporting the first causative missense variant, p.(Cys323Arg). Motor nerve conductions were markedly decreased. Nerve microscopical lesions confirmed a severe hypomyelinating process and showed loss of attachment sites of the myelin loops on the axons, which could be a characteristic of Caspr loss-of-function. We discuss the pathophysiology of the myelination process and we propose to consider this disorder as a congenital hypomyelinating neuropathy.

Treatment responses in five patients with Ribbing disease including two with 466C>T missense mutations in TGFß1.

OBJECTIVE: To assess 5-year treatment responses and TGFB1 gene abnormalities in five patients with ribbing disease. METHODS: PCR analysis and bidirectional sequencing of TGFß1 exons 1 through 7 were performed in all five patients. RESULTS: The five patients, four women and one man with a mean age of 34 years at symptom onset, shared the following features: severe diaphyseal pain predominating in the lower limbs with diaphyseal hyperostosis; increased radionuclide uptake at sites of pain and, in some cases at other cortical sites; asymmetric or asynchronous lesions; long symptom duration (5-18 years) despite a variety of treatments; and a delay of several years (2-15) between symptom onset and the diagnosis. Of our five patients, two had a heterozygous missense mutation in exon 2 of TGFß1 (c.466C>T, p.Arg156Cys, previously described in Camurati-Engelmann syndrome) and three had commonly found TGFß1 polymorphisms. Intravenous bisphosphonate therapy was used in all five patients but induced substantial improvements in a single patient. Of the three patients given bolus methylprednisolone therapy, two experienced a lasting response; the exception was one of the two women with a TGFß1 mutation. CONCLUSION: Considerable heterogeneity in the clinical presentations, genetic abnormalities, and treatment responses contribute to the diagnostic challenges raised by ribbing disease. Detailed genetic studies are needed.