The IgM B. miyamotoi test detects early antibodies against Borrelia miyamotoi, a relapsing fever–type spirochete transmitted by the same Ixodes ticks that spread Lyme disease. Unlike classical Lyme borreliosis, B. miyamotoi causes Borrelia miyamotoi disease (BMD), which typically presents with acute, flu-like illness and recurring episodes of fever, and in some cases, neurological complications such as meningoencephalitis, particularly in immunocompromised patients. Importantly, BMD rarely produces the bull’s-eye rash seen in Lyme disease, making antibody testing critical for recognition. A positive IgM result generally indicates recent or active infection, but interpretation should take clinical symptoms, geographic exposure, and confirmatory testing into account, since cross-reactivity with Lyme Borrelia is possible. 

An equivocal result means the antibody level is close to the test’s cut-off, and may reflect very early infection, low-level cross-reactivity, or a nonspecific finding; in such cases, repeat testing or additional confirmatory assays are often needed for clarity.

The IgM Babesia test measures early antibodies against Babesia species, tick-borne protozoan parasites that invade red blood cells and can cause babesiosis, a malaria-like illness. In North America, Babesia microti is most common, while B. divergens and B. venatorum predominate in Europe, often leading to more severe disease. IgM antibodies typically appear within 1–2 weeks of infection, making this marker useful for identifying recent or acute cases before IgG antibodies or confirmatory findings emerge. Clinically, babesiosis can range from flu-like symptoms (fever, chills, sweats, fatigue) to hemolytic anemia, splenomegaly, and multi-organ complications, especially in elderly or immunocompromised patients, or those without a spleen. Because the same ticks can also transmit Lyme disease (Borrelia) and Anaplasma, co-infections are common and can complicate the illness. 

An equivocal IgM Babesia result means antibody levels are near the cut-off, making the finding uncertain; this may reflect very early infection, low-level reactivity, or nonspecific response, and repeat or confirmatory testing is often needed for clarification.

The IgM Bartonella test detects early antibodies against Bartonella species, a group of bacteria transmitted by ticks, fleas, lice, or scratches from infected animals (especially cats). The most common human pathogens are Bartonella henselae and Bartonella quintana, which can cause cat scratch disease, trench fever, or tick-borne bartonellosis. In some cases, Bartonella infections may contribute to chronic fatigue, neurological issues, or joint pain, especially when co-infections with Lyme disease or Babesia are present.

IgM Cytomegalovirus (CMV) measures the level of IgM antibodies, which are the body’s first line of defense when encountering a virus. These antibodies typically appear during a new CMV infection or during viral reactivation. Because CMV is a common virus—often acquired in childhood—IgM testing helps determine whether your immune system is responding to a recent or ongoing infection.

CMV IgM is often used together with CMV IgG, clinical symptoms, or PCR testing to clarify whether the infection is new, reactivating, or clinically significant.

What It Means When Your IgM CMV Result Is Within the Reference Range (Negative)

A negative or normal IgM CMV result means there is no evidence of a recent or active CMV infection at the time of testing.

When IgM is within the reference range:

• Your immune system is not producing new CMV-specific IgM antibodies.

• There is no laboratory indication of a current or very recent infection.

• Viral reactivation is unlikely based on this marker alone.

• If you have CMV IgG antibodies, they reflect past exposure only, not new illness.

A negative IgM result is reassuring and is the most common finding in healthy individuals.

IgM EB Nuclear Antigen (EBNA IgM) measures early antibodies directed against the Epstein–Barr Virus (EBV) Nuclear Antigen. Unlike other EBV markers, such as VCA IgM, EBNA IgM is not commonly produced and is generally not a standard marker of acute infection. When it does appear, it may indicate an early-phase immune response, but it is less specific and less commonly used in clinical decision-making.

Because EBNA proteins are expressed later in the EBV life cycle, IgM antibodies to EBNA are rarely detected during typical EBV infections. For this reason, clinicians rely more heavily on VCA IgM, VCA IgG, EBNA IgG, and Early Antigen when evaluating EBV activity.

EBNA IgM can sometimes be included in extended EBV panels to help rule out atypical or early immune responses.

What It Means When Your EBNA IgM Result Is Within the Reference Range (Negative)

A negative or normal EBNA IgM result means there is no evidence of a recent or acute immune response to the EBV Nuclear Antigen. In practical terms, this indicates:

• Your immune system is not producing early-phase EBNA-specific IgM antibodies.

• There is no laboratory support for an active or newly developing EBV infection based on this marker.

• This result is consistent with the vast majority of healthy individuals, as EBNA IgM is typically not elevated even during routine EBV infections.

When EBNA IgM is within the reference range:

• EBV infection is unlikely to be recent.

• If other EBV markers (VCA IgM, EA IgG) are also negative, it supports the conclusion that EBV is not active.

• Past infection—if present—would be reflected in EBNA IgG, not in this marker.

A negative EBNA IgM result is expected and reassuring, especially in the absence of symptoms suggestive of acute mononucleosis.

The IgM Ehrlichia test detects early antibodies to Ehrlichia species, tick-borne bacteria that invade white blood cells and cause ehrlichiosis, most often due to E. chaffeensis (human monocytic ehrlichiosis) or E. ewingii. IgM antibodies usually appear within 1–2 weeks of illness, making this marker useful for identifying recent or acute infection, particularly in patients presenting with fever, severe headache, fatigue, muscle aches, gastrointestinal upset, or neurological changes. Laboratory findings commonly include low white blood cells, low platelets, and elevated liver enzymes. Because ehrlichiosis can progress rapidly to severe complications in older adults, immunocompromised patients, or those with delayed treatment, timely recognition and empiric doxycycline therapy are critical. However, IgM alone is not definitive since early levels can be low and false positives may occur. 

An equivocal IgM Ehrlichia result means the antibody level is near the cut-off, leaving the test uncertain; this may reflect very early infection, a nonspecific immune response, or cross-reactivity, and repeat or confirmatory testing (PCR or IgG serology) is often needed.

IgM Epstein–Barr Virus Viral Capsid Antigen (EBV VCA IgM) measures early antibodies produced by the immune system during a new or recent Epstein–Barr virus infection. EBV is a common virus best known for causing infectious mononucleosis (“mono”), especially in adolescents and young adults.

VCA IgM antibodies are typically:

• Detectable during the acute phase of infection

• Present for only a short period (usually several weeks)

• Used to help identify whether symptoms—such as fatigue, swollen lymph nodes, sore throat, or fever—are related to a current EBV infection

Because IgM rises quickly and declines relatively fast, it is a key marker for determining if EBV infection is occurring now or very recently.

What It Means When Your IgM EBV VCA Result Is Within the Reference Range (Negative)

A negative or normal IgM EBV VCA result means there is no evidence of a recent or active Epstein–Barr virus infection at the time of testing.

When this marker is within the reference range:

• Your immune system is not producing early, active-phase EBV antibodies.

• There is no laboratory indication of a current mono-like infection.

• Any past exposure you may have had is not recent—and would instead be reflected in EBV IgG markers, not IgM.

• This result is reassuring and is the most common finding in individuals without active symptoms.

A negative IgM result is especially helpful when interpreting the rest of the EBV panel; it supports the conclusion that EBV is not driving current symptoms.

If symptoms persist, clinicians may look at additional markers—such as EBV EBNA IgG, EBV VCA IgG, or Early Antigen (EA)—to build a more complete picture.

The IgM Immunodominant C6 test measures early antibodies against the conserved C6 peptide of VlsE, a key surface protein of Borrelia burgdorferi sensu lato. Because the IR6 region of VlsE is highly conserved across major Lyme-causing subspecies (B. burgdorferi sensu stricto, B. afzelii, B. garinii), C6-based assays serve as valuable pan-Borrelia markers in Lyme serology. IgM to C6 typically appears within 1–3 weeks of infection, making it especially useful for detecting recent exposure, particularly in patients with early localized symptoms, neurological manifestations, or evolving musculoskeletal involvement. While C6 ELISAs show strong sensitivity and specificity, IgM alone is not diagnostic—isolated IgM after 6–8 weeks or cross-reactivity with other pathogens (including Borrelia miyamotoi) can lead to nonspecific results. 

An equivocal IgM C6 result means antibody levels are near the cut-off, leaving interpretation uncertain; this may reflect very early infection, low-level reactivity, or a nonspecific immune response, so repeat or confirmatory testing is often required.

The IgM LFA Antigen + CK10 test measures two important parts of the immune system. The IgM portion looks for the body’s early-response antibodies, which usually appear soon after an infection begins, such as from a virus, bacteria, or parasite. Detecting IgM often suggests a recent or ongoing infection, while unusually persistent IgM levels may also point to chronic immune activity. The CK10 portion of the test checks for antibodies against cytokeratin 10, a protein found in skin and epithelial cells. Antibodies to CK10 can be a clue that the immune system is mistakenly targeting the body’s own tissues, as seen in certain autoimmune skin or inflammatory conditions. Together, these markers can help distinguish whether symptoms are more likely due to infection, autoimmunity, or both. 

If results are reported as equivocal, antibody levels are near the cut-off, meaning the test is uncertain; in these cases, repeat or confirmatory testing is often recommended.

IgM OspA + OspC

The IgM OspA + OspC test helps detect an early immune response to Borrelia burgdorferi, the bacteria that cause Lyme disease. It looks for IgM antibodies against two important surface proteins:

• OspC (Outer Surface Protein C): Typically produced within the first 2–3 weeks after infection, making it a strong marker for early Lyme disease.

• OspA (Outer Surface Protein A): More often linked with later or persistent infection, and sometimes associated with chronic or autoimmune-like Lyme symptoms.

By measuring IgM antibodies against both proteins, this test provides a broader view of where a person may be along the Lyme disease timeline.

Why It Matters

The IgM OspA + OspC test can be useful for people who have:

• Early Lyme symptoms such as rash, fever, fatigue, or muscle pain

• Neurological signs including facial palsy or nerve discomfort

• Joint pain or swelling that appears weeks to months after infection

• A history of tick exposure in areas where Lyme disease is common

Things to Keep in Mind

IgM antibodies are most reliable in the early weeks of infection. On their own, they cannot confirm Lyme disease. False positives are possible, which is why doctors often order additional testing (such as IgG antibodies, VlsE/C6 peptide, or multi-antigen panels) to confirm results.

Patient Takeaway

A positive IgM OspA + OspC test suggests that your immune system is reacting to Borrelia and may indicate a recent or active infection. However, your healthcare provider will always consider your symptoms, exposure history, and other test results before making a diagnosis.

If your result is reported as equivocal (borderline), it means the antibody level is close to the cutoff and not clearly positive or negative. In this case, repeat testing or confirmatory panels are often recommended to clarify the result.

The IgM OspE test detects early antibodies against Outer Surface Protein E (OspE) of Borrelia burgdorferi, the bacterium responsible for Lyme disease. OspE belongs to the Erp (OspE-related proteins) family, which helps Borrelia survive in the human bloodstream by binding to factor H, a host protein that protects the bacteria from complement-mediated killing.

The IgM Variable Major Protein E (VmpE) test detects early antibodies against a surface protein that Borrelia burgdorferi—the bacteria responsible for Lyme disease—uses to survive through antigenic variation. VmpE can repeatedly alter its structure, enabling Borrelia to evade immune detection and, in some cases, contribute to persistent or relapsing infection.

IgM antibodies to VmpE usually appear within the first 1–3 weeks after infection, making this test valuable for identifying recent exposure to Lyme disease. In some cases, IgM reactivity may also remain detectable in ongoing immune activation, offering insights into possible bacterial persistence.

Clinically, IgM VmpE provides complementary information to markers such as OspC and VlsE, helping clinicians assess both early immune recognition and potential long-term Borrelia activity.

As with all IgM-based assays, results must be interpreted alongside patient history, symptoms, and additional confirmatory markers.

An equivocal IgM VmpE result means antibody levels are near the test cut-off, leaving the finding uncertain. This may reflect very early infection, a nonspecific immune response, or cross-reactivity. In such cases, repeat or follow-up testing is usually recommended to clarify the result.

IL-1 beta refers to Interleukin-1 beta. Interleukin-1 beta is one of the cytokines assessed in the CytoDx Cytokine Response Profile offered by Diagnostic Solutions Laboratory. Cytokines are critical mediators of immune responses, and their imbalances have been linked to chronic inflammation and autoimmune diseases.

IL-10 (Interleukin-10) is a powerful anti-inflammatory cytokine that helps control immune overactivation and maintain immune tolerance. Produced by regulatory T cells (Tregs), monocytes, and macrophages, IL-10 suppresses excessive inflammatory signals and supports healing once an immune threat is cleared. Elevated IL-10 levels may indicate the body’s effort to calm chronic inflammation or infection, while low IL-10 often reflects poor immune regulation and a higher risk of autoimmune or inflammatory disorders. Within the Cytokine Response Profile (CytoDx) by Diagnostic Solutions Laboratory, IL-10 serves as a key marker of regulatory immune balance, helping clinicians assess whether inflammation is being effectively resolved or remains persistently active.

IL-13 (Interleukin-13) is an anti-inflammatory Th2 cytokine that regulates antibody production, tissue repair, and mucosal immunity. Produced by Th2 cells, mast cells, and ILC2s, IL-13 helps resolve inflammation but can also drive allergic and fibrotic responses when elevated. High IL-13 levels are linked to asthma, eczema, allergic rhinitis, and fibrotic diseases, indicating Th2 immune dominance. Low IL-13 may occur in autoimmune or Th1/Th17-driven inflammation, reflecting reduced regulatory control. Within the Cytokine Response Profile (CytoDx) by Diagnostic Solutions Laboratory, IL-13 serves as a marker of anti-inflammatory activity and immune balance, helping clinicians determine whether the immune system is effectively resolving inflammation or skewed toward chronic allergic or inflammatory stress.

IL-15 (Interleukin-15) is a pro-inflammatory cytokine that activates natural killer (NK) cells and CD8+ T cells, strengthening the body’s defense against infections and tumors. It also promotes interferon-gamma (IFN-γ) production, amplifying immune responses. Elevated IL-15 levels can indicate chronic inflammation, autoimmune activity, or persistent infection, and are often seen in conditions like rheumatoid arthritis, celiac disease, and inflammatory bowel disease. Low IL-15 may suggest reduced immune cell function or immune suppression. Within the Cytokine Response Profile (CytoDx) by Diagnostic Solutions Laboratory, IL-15 serves as a marker of Th1-driven immune activation, offering valuable insight into immune system stress and helping guide targeted approaches to restore immune balance and resilience.

IL-17A (Interleukin-17A) is a pro-inflammatory cytokine produced by Th17 cells that plays a key role in defending against bacterial and fungal infections. It promotes neutrophil recruitment and stimulates other inflammatory cytokines like IL-6 and TNF-α. Elevated IL-17A levels indicate Th17-dominant inflammation and are commonly seen in autoimmune diseases, psoriasis, IBD, and chronic inflammatory conditions. Chronically high IL-17A can drive tissue damage and immune dysregulation, while low IL-17A may signal weakened mucosal immunity or immune suppression. Within the Cytokine Response Profile (CytoDx) by Diagnostic Solutions Laboratory, IL-17A helps identify chronic inflammatory patterns and autoimmune activity, offering valuable guidance for restoring immune balance and reducing inflammation.